Headers & exhaust

[TomZR1]

I have 90 zr1 bought it 5 months ago looking to up grade exhaust ,like to do headers is it woth the money & noticeable hp Gaines & what brand, wher to get em. What about mufflers or cat back system? I think resanator is stock,Car has flow master mufflers they look ugly looks like 4 tubes coming out of the rear, correct me if I'm wrong stock resonator has no cuts going to y pipe it's all one ,mines cut with clamps to muffler with clamps, resonator has no markings so I'm guessing stock sounds good but looks like crap.any info or pics would greatly appreciate it thanks.

[WARP TEN]

I have 90 zr1 bought it 5 months ago looking to up grade exhaust ,like to do headers is it woth the money & noticeable hp Gaines & what brand, wher to get em. What about mufflers or cat back system? I think resanator is stock,Car has flow master mufflers they look ugly looks like 4 tubes coming out of the rear, correct me if I'm wrong stock resonator has no cuts going to y pipe it's all one ,mines cut with clamps to muffler with clamps, resonator has no markings so I'm guessing stock sounds good but looks like crap.any info or pics would greatly appreciate it thanks.

Welcome to the group, tom. I would suggest a look at Marc Haibeck's website to give some ideas of power increases. http://www.zr1specialist.com/. Long tube headerrs are under "Products" and there is a presentation on exhuast systems from the 2011 BG gathering. Do you need cats for emissions? Long tube headers add about 25 hp, and a Corsa exhaust adds about 10 or so. You can get high flow cats but they do slightly reduce power, maybe 5-8 hp. Stainless Works and OBX (SW knockoffs) are header possibilities. Marc says Corsa shows the best power gains but others are close. --Bob

[We Gone]

The best way to tell if you have a stock resonator is two pipes in two out, the Flowmaster resonator has both pipes join into one 3" pipe at the inlet than 2 out.
I did my header Stainless Works coated long tube as my first mod many years ago 08 and was very happy with the results. They have held up very well still look great. I have them hooked to 3" high flow cats and Corsa passes the treadmill test for emission with no problem.

[TomZR1]

If reasanateris stock ,is there hp to gain if replaced with b&b or corsa.

[TomZR1]

Don't need converters ,so headers ,full exhaust will gain about 35-40 hp .

[We Gone]

If reasanateris stock ,is there hp to gain if replaced with b&b or corsa.

Not sure about B&B but the Corsa system only comes complete as a cat back set up. When you buy the SW headers you can get an adapter to hook from header flange to pipes with out cats.

http://www.stainlessworks.net/1990-95-vette-off-road-headers-fits-factory-conn-point.html

[TomZR1]

Don't really like tips on these after market mufflers,maybe can do flowmaster with single outlet & 95 tips. Lets go back in time does any one remember flowmaster had a cat system 3inch exhaust with 90-92 tips

[We Gone]

Tom,

I just took the old type ZR-1 cat back Flowmasters off they do not sell it anymore. I'm putting on my LT1 car.

http://imagizer.imageshack.us/v2/800x600q90/511/p3310029d.jpg

http://imagizer.imageshack.us/v2/800x600q90/24/c40c.jpg

[WARP TEN]

If reasanateris stock ,is there hp to gain if replaced with b&b or corsa.

If your resonator is a stock 90 unit, there are gains available. Marc's presentation on exhausts clearly demonstrates that. --Bob

[edram454]

I think long tube headers are well worth it. Very good gains throughout the whole rpm range and especially high rpms. The previous owner of my car bought the DRM ceramic coated long tube headers and he put the flowmaster force II exhaust system on it. He lived in pennsylvania and he had to pass emissions so he took the cats off and put the flowmaster resonator which he convinced them were cats. This car passed emissions every year and the stickers are on my windshield to prove it. the car sounds great with no mid rpm drone that most systems have. the corsa's sound tinny, ratty and the horsepower gains are not substantial and debateable. Unfortunately you cannot get the flowmaster system any more so you would have to make choices here. Definately get long tube headers if you want to really take advantage of your ZR1's power. I would go for the best sounding system as far as cat back exhaust is concerned. You are not talking a bunch of horsepower difference here. the gain in horsepower will be with your long tube headers. get the best sounding catback and dont get caught in that 1 horsepower or 2 horsepower counting game that most manufacturers want to you believe. does it matter if your catback makes 2 horsepower less on a particular day and on a particular car anyway... it just has to sound the way you like it.

edramos #3028

[TomZR1]

Steve,that's it i can't even find a picture of that flowmaster on line anywhere,your z color is awsome, flowmaster has a similar set up to that, it looks like its painted silver but I like the tips

[TomZR1]

Any difference drm or sw headers besides price?

[We Gone]

Steve,that's it i can't even find a picture of that flowmaster on line anywhere,your z color is awsome, flowmaster has a similar set up to that, it looks like its painted silver but I like the tips

Thanks Tom, unfortunately Flowmaster does not make the ZR-1 system anymore I painted mine black. I think it does have a better tone than the Corsa's. I still have to run cats for a few more years. The Corsa did have a very tinny sound at first, but after I put the cats back on it gave them a deeper sound and they loss the tinny sound.

[TomZR1]

Is any one here running flowmaster force 11

[edram454]

yes. i am running flowmaster force 11 with long tube ceramic coated headers. no cats but am running the flowmaster resonator. great sound,,, no drone... not too loud idle.. great sound on the road and fantastic during full throttle.

[edram454]

the exhaust system has three power killers,, stock exhaust manifolds, cats,, stock resonator. if you eliminate these three power robbers, your car will definitely pick up quite a bit across the board. No shorty headers either, long tube only.

[TomZR1]

Do you have picture of exhaust ,where best place to order

[We Gone]

Do you have picture of exhaust ,where best place to order


Unless you can find one used Flowmaster no longer makes the force 2 setup for the ZR-1. I believe the mufflers are a series 50 but don't know if they come in a duel outlet.

[USAZR1]

Has anyone used the Stainless Works cat-back exhaust on their ZR-1? I really like its looks and am looking at it for our 94.
FWIW,I had Jeal headers and Flowmasters on my former 90 Z and it sounded awesome,IMO.

[1990 quasar blue]

Is any one here running flowmaster force 11

I am. The reason that I bought it was for
the "stockish" style tips. That being said
they sound great. I get compliments on
the sound all the time. I also have very little
resonance. They're behind SSW headers
and random tech cats.
With all that being said, I'm really thinking
about switching to the FBI set up. I think
those guys nailed it. Probably the best flow
while still keeping a quiet interior.

[TomZR1]

Been looking and calling everywhere for the flowmaster force11,part #17115 and nothing.Is there anything out there similar to it or someone willing to sell. How is the b&b set up

[Schrade]

I think there's a Group Buy, of some hardware, in the works there TomZR1; if you don't want in on it, maybe someone else who IS might unload their old pipes to ya' there...

[Halinmontana]

Does anyone else have the OBX racing exhaust on theirs? Mine came with this and it sounds great. Good deep sound with no tinny high pitch.

Hal

[efnfast]

Hal, I have the OBX headers and exhaust, don't know if it's the racing or not. I've been very happy with it, and happy with the sound. I have very little to compare it too other than stock.

[Schrade]

Does anyone else have the OBX racing exhaust on theirs? Mine came with this and it sounds great. Good deep sound with no tinny high pitch.

Hal

I think Jeff - user 'Shrek', from whom I got the outpipes, has OBX on his wife's car...

Hope he doesn't mind me linking his public file (http://s446.photobucket.com/user/2manyvettes24/media/Power%20Effects%20Exhaust/ZR-1PowerEffectsClosed_zps10cc28f4.mp4.html?sort=3&o=2) here... Sounds NASTY!

[1990 quasar blue]

Been looking and calling everywhere for the flowmaster force11,part #17115 and nothing.Is there anything out there similar to it or someone willing to sell. How is the b&b set up

http://www.flowmasterdirect.com/2081.html

[TomZR1]

I tried them they don't have it ,thanks I think I'm going to go with b&b 3 inch exhaust.

[TomZR1]

I really really love the look of 90 mufflers , thinking of b&b exhaust but I think to much bling found 91 stock cat back 1000 miles on it for $100 bucks, my question is I have flowmaster on now if I change to stock mufflers( like the look) will there be any noticeable hp difference.can I change resonator? And go with sw headers ,do I have to do anything with chip?

[We Gone]

You can get SW headers with cats, if you don't have to run cats SW sells an adapter to hook their headers to a stock exhaust. As to flow Marc H. has some good write ups on his site.

http://www.zr1specialist.com/HAT%20Web/presentations/Presentations%20Page.htm

[edram454]

I think I would try the obx headers and exhaust. the headers will give you the power and the rest of the cat backs is just sound. I would get rid of the cats and get a resonator for droon control. make sure nothing is under 2.5 inch width on the pipes and resonator. I think you will see a power increase. I have seen some people that have bought the obx say they are good and the price is right.

edramos #3028

[Schrade]

Does anyone else have the OBX racing exhaust on theirs? Mine came with this and it sounds great. Good deep sound with no tinny high pitch.

Hal

I found my OBX HAB055; something that Jeff [Shrek] said when I picked up the 3'' PE pipes from him, was leading me to believe that they were dis-continued.

Both places are eBay sellers however. Anyone dealt with MOTORSPORTAUCTIONS, or Racing Parts Depot???

Anyone know of other OBX sellers?

[Karl]

I purchased my OBX headers directly from Racing Parts Depot. Everything went great! Lowest price on the web that I found for the headers is directly through RPD.

[Paul Workman]

Performance is quantifiable, sound is more subjective.

Performance wise, Marc suggests the Corsa with headers, sans cats, if allowed. The package delivers performance gains w/o resonance (I'm told), but they do have a "tinny" sound that some like and others do not.

The 3" Magnaflow system gives a nice, deep tone w/o resonance. However, the resonator chokes down the inlet to a single ≈ 3" perforated tube running the length of the resonator. Furthermore, there are several abrupt(!) choke and sudden transition points throughout the Magnaflow system (6 on the right side, 5 on the left) (which I believe any flow dynamics expert will tell us is NOT conducive to performance. FWIW).

The B&B has evolved from a pretty much wide open 3" cat-back with significant drone in the 1900-2200 rpm range, to a more restrictive system and "lesser" drone.

Pete, ever experimenting to get the most hp, is running a modified version of the earlier B&B system with Watson headers, and now using the NPP valves to control in-cabin drone. (The word is he can now carry on a conversation since installing the NPPs. Others too have gone that route and agree). Nobody is going to convince Pete that a Corsa is better for performance.

Experimenting goes on. I'm a Warrior (at least in my mind and I try to be:p) which means I'll put up with a little racket if there's hp to be made. I've watched the FBI efforts with great interest, and I believe the gurus have come up with what I consider the best of both worlds - to date at least:

The system that impresses me is the headers (SW or Watson), sans cats, SW type X pipe, no resonator, the Dynamax 17228 muffs with the NPP type gate affixed to one of the two active muffler outlets.** It is a true 3" system from the header collectors to the muffler inlets for least restriction and max performance, and the valve on one of the muffler outlets reduces resonance to a very tolerable level. What's not to like???

I'm not sure what Marc's setup is, but I don't believe it is a Corsa. And, I know he likes quiet for normal driving and has a pair of the Flowmaster dual outlet muffs on the back with 4-bolt flanges on the inlet side so they can be easily removed at the track. A variation of that is to install cut-outs just behind the differential which is perhaps an alternative to the NPP and perhaps just as effective.

Fact is, all of them are a compromise in some respect. Sound, vs. performance, vs. cost... Always room for more experimentation - and new "stuff"!;)

[XfireZ51]

Paul,

As you know several of us are also adapting a Mild 2 Wild capability with the
C6Z NPP exhaust valves. Hoping to get mine re-installed sometime next week weather depending.

[Paul Workman]

Paul,

As you know several of us are also adapting a Mild 2 Wild capability with the
C6Z NPP exhaust valves. Hoping to get mine re-installed sometime next week weather depending.

Yes - thought I alluded to that system. Yours, BTW, to me is the best sounding one so far.

And, speaking of NPP conversions, "Mike 100" has installed a very well thought out and proven electro-mechanical modification to the passive vacuum-only NPP conversion approach. It was engineered to addresses some low plenum pressure issues the simpler conversion that us "FLAT LANDERS" don't run into, e.g, Mountains and high altitude (low manifold) pressure issue. A really well documented and tested system!

Registry members have first DIBBS. It will be a feature article in the next HOTB!

[TomZR1]

What's the difference between resonance & drone? I know one of them means inside the cab is very loud, the more research I do the more these catback system have drone or resonance from what I'm reading on various forums especially b&w triflow, not to much with older style flowmaster with squarish tips wich I'm leaning towards. Or leaving on stock exhaust and putting on sw headers, and see if I can find a high flow resanator ?

[TomZR1]

So basically most hp gain with no annoying noise in cab.

[Karl]

My b&b with x-pipe isn't that bad. Sounds good to me and I can talk on my cell phone and drive without the exhaust being a problem.

But I have not installed my headers yet.

[Karl]

My b&b with x-pipe isn't that bad. Sounds good to me and I can talk on my cell phone and drive without the exhaust being a problem.

But I have not installed my headers yet.

[Karl]

What's the difference between resonance & drone? I know one of them means inside the cab is very loud, the more research I do the more these catback system have drone or resonance from what I'm reading on various forums especially b&w triflow, not to much with older style flowmaster with squarish tips wich I'm leaning towards. Or leaving on stock exhaust and putting on sw headers, and see if I can find a high flow resanator ?


If I could do it over I would install an x-pipe to replace the resonator and swap out the mufflers and connect everything to a set of full length headers.

The factory system is overall 2 3/4" & stainless steel.

[Gunny]

Performance wise, Marc suggests the Corsa with headers, sans cats, if allowed. The package delivers performance gains w/o resonance (I'm told), but they do have a "tinny" sound that some like and others do not.


Corsa w/headers, sans cats has absolutely no resonance but is LOUD. The sound is different (subjective observation). I had this system but grew weary of the LOUD (i.e. I could no longer drive around my small town without attracting a LOT of unwanted attention; resonance was never an issue.

My current solution is headers, no cats, and an LT-4 stock exhaust from the collectors back. No resonance and sounds stock in the cabin, but somewhat louder outside. Without a dyno comparison I can't comment on HP loss but in real-world driving it doesn't seem that I lost much, if any, and it "feels" like I picked up a little torque. Again, without a dyno that doesn't really mean anything but I'm reasonably happy with the system ... for now.

The system that impresses me is the headers (SW or Watson), sans cats, SW type X pipe, no resonator, the Dynamax 17228 muffs with the NPP type gate affixed to one of the two active muffler outlets.** It is a true 3" system from the header collectors to the muffler inlets for least restriction and max performance, and the valve on one of the muffler outlets reduces resonance to a very tolerable level. What's not to like???
I haven't heard this setup yet but this might be my next direction should I want to change the exhaust again.

[emmvette]

What's the FBI set-up consist of?

[Paul Workman]

What's the FBI set-up consist of?

Marc favors the Corsa cat-back, but what Pete and others are using with success (in a fashion) is a "work in progress", but this may come pretty close as of now:


SW or Watson headers,
3" pipes throughout,
sans cats and resonator,
SW or B&B type X pipe*,
Dynamax 17228 or B&B muffs 3" in, twin 2" out
NPP** valve on one of each twin outlet, OR cut-out valve at the differential
B&B or C6 Z06 tips.


* Bob G is using what could be described as an X "box"
**NPP valves are controlled by simply supplying vacuum from the plenum to the valves, or manually electrically activated.

http://i185.photobucket.com/albums/x220/6PPC_bucket/tech%20files/StainlessWorks2001Large.jpg (http://s185.photobucket.com/user/6PPC_bucket/media/tech%20files/StainlessWorks2001Large.jpg.html)

Note: The simple vacuum system works well in relatively flat terrain. However, in mountainous areas, the simple plenum vacuum approach results in the valves being open "too much". The fix is what I was alluding to in the next HOTB.

P.

[Blue Flame Restorations]

Pretty sure the 17228 mufflers are 2.5" dual outlets. Not 2"

FYI

[Schrade]

What did you end up doing there Tomz?

Take any snappics? Did you pull the FlowMasters on there now?

I'm about to put on OBX's + PE pipes, and looking for more shots of the work...

[WARP TEN]

Corsa w/headers, sans cats has absolutely no resonance but is LOUD. The sound is different (subjective observation). I had this system but grew weary of the LOUD (i.e. I could no longer drive around my small town without attracting a LOT of unwanted attention; resonance was never an issue.

My current solution is headers, no cats, and an LT-4 stock exhaust from the collectors back. No resonance and sounds stock in the cabin, but somewhat louder outside. Without a dyno comparison I can't comment on HP loss but in real-world driving it doesn't seem that I lost much, if any, and it "feels" like I picked up a little torque. Again, without a dyno that doesn't really mean anything but I'm reasonably happy with the system ... for now.

George, this is exactly what I went through. Primarily Corsas over the years but just got tired of the Loud. I have headers, no cats and last year had Marc reinstall my stock '95 system from the headers back. The only difference is I had him add electric QTP cutouts and I installed a rocker switch hidden under the carpet on the right side of the console. The only issue is I had to sacrifice the spare tire carrier. On longer trips away from home I carry the spare in the back. I added small tips to direct the exhaust to the side. So far I like the setup a lot. It is stock quiet when I want and when open I can scare children and pets and set off car alarms. I normally run slightly open for a little rumble.--Bob

[TomZR1]

Hey schrade,ordered flowmaster catback actually yesterday took a while to find them cause they were discontinued but I found them,will figure out how to post pics when done installing them,headers will be next what's difference between obx & sw? Is it sound,looks I know thers big price difference . Thanks ill keep you posted.

[Schrade]

Hey schrade,ordered flowmaster catback actually yesterday took a while to find them cause they were discontinued but I found them,will figure out how to post pics when done installing them,headers will be next what's difference between obx & sw? Is it sound,looks I know thers big price difference . Thanks ill keep you posted.

I don't know much about the differences - when I said I know less than most on the boards, I was meaning exactly that...

Cliff [Dynomite] has one method step-by-step for uploading snappics here (http://www.zr1.net/forum/showthread.php?t=16196). You can practice a few carshots upload before the hardware gets here... Learning stuff like that has application in how some of the Z diagnostic stuff works too - promise.

Work shots are good in MANY ways - it forces you to take your time (always good), gives you more time to see where stuff is, good for re-assembly reference, feedback from others, if you ever sell, you got photo-doc'ed proof, you 'learn' the stuff better (I will NEVER forget steps involved in the Top End Resto thread (http://www.zr1.net/forum/showthread.php?t=21439) ('til tomorrow anyway :mrgreen: )

[edram454]

Hey schrade,ordered flowmaster catback actually yesterday took a while to find them cause they were discontinued but I found them,will figure out how to post pics when done installing them,headers will be next what's difference between obx & sw? Is it sound,looks I know thers big price difference . Thanks ill keep you posted.

Tom,

where did you find them?? I have flowmaster force II system and they are discontinued so I thought. Are they making them on a custom order method or did you just get lucky and find an old set somewhere?

ed ramos #3028

[TomZR1]

Hi Ed, i got lucky typed 17115 flowmaster and bunch of company's popped up called every one,and all but one said nope don't have discontinued,finally one company said I have one on shelf,holy crap ill take it!!! So if you can't find something don't give up its out there somewhere.

[edram454]

man u lucky dog. I think its the best system out there. I have had flowmasters in various cars and its always been a good product. I love the sound and the lack of drone. dont use the cats if you dont need too. Just the resonator and mufflers and you will love the sound. I dont need a new exhaust system or anything just the thought that you cant get any more makes me want to buy another spare. The pipes are galvanized steel so they will last a very, very long time. Good luck and enjoy your new flowmaster exhaust.

ed ramos #3028

[Schrade]

Tom,

where did you find them?? I have flowmaster force II system and they are discontinued so I thought. Are they making them on a custom order method or did you just get lucky and find an old set somewhere?

ed ramos #3028

Who DID have 'em there Tomz? We might be able to get more parts from 'em...

Did you get some snappics of the car uploaded there?

[TomZR1]

Got them from tko performance .com guys name is Ed ,as for pics I'm working on it wright now hopefully I can post them.

[TomZR1]

Here's the exhaust I have on it right now looks hacked up

[TomZR1]

I will post more pictures when exhaust is done and car is detailed. The car is a mess right now and the garage in under construction.

[Schrade]

I will post more pictures when exhaust is done and car is detailed. The car is a mess right now and the garage in under construction.

What's wrong with the car? Looks pretty good to me...

(and INSIDE TOO http://www.zr1.net/forum/images/icons/icon14.gif ; if it was my setup, the sleeping bag and toothbrush would be near the car - I can't hack under 40' - to easy to drop bolts with cold digits)

[edram454]

About exhaust systems in general. When I was racing the quarter mile, we did many test on exhaust systems. We discovered that the biggest exhaust system is not always the best system as far as making power. 3 inch dual exhaust system is for cars making tons of power.. lets say 600 hp or more. big inch pipes will move more exhaust out but if you dont have the power, it will kill your torque numbers too. LT5's are not known for there torque so cars that are not stroked to a bigger size or heavily modified will suffer in the low end big time. I had a 468 cube Corvette that I decided to put full competition side mount headers on it and even after a fresh rebuild I lost torque compared to my stock exhaust manifolds. I should have bought the regular competition header which were smaller and created some back pressure to maintain good torque numbers. I finally decided, since those exhaust cost me so much money, to change the rear gear to a 3.55 from a 3.08 diff to try to make up for the torque that I was losing.

On the other hand, on my 1200 hp mustang I had 4 inch exhaust dumping to 5 inch supertrapp mufflers. That car had to have that kind of exhaust but I dont think our zr1's will benefit much with 3 inch exhaust and will lose a certain amount of torque. I would imagine that on big inch 415 cube lt5's it would work good but on the rest I would bet it would not work as good as 2.5 inch exhaust. Of course if you put cats on anything you are destroying top end and torque numbers. If all you require is a visual the hollow out the cats. One 3 inch pipe flows more than 2 2 inch pipes for example. 2 2.5 inch pipes is just what the doctor ordered on most of our torqueless cars. Our cars are rpm horsepower makers and everybody knows that torque always wins on the street. I would not sacrifice any of my torque just to put a bigger pipe and maybe some more peak horsepower. By the time you get to your peak power at 7200 rpm... the race is over.

fyi.

ed ramos #3028

[Schrade]

I think I've read that bigger pipes allow the gasses to cool quicker. And cooler gasses are heavier.

If so, more 'power' is needed to push the heavier mass to the rear.

Is there some additional theory here?

Turbulence? Laminar flow?

Header wrap to retain the gasses' heat?

At what point is the resonator restriction inlet of '90 overcome with bigger pipes? What size???

ed.:
How much torque did you lose on those machines there Ed? Did you ever get dyno graphs before and after?

[mike100]

...3" pipe discussion...

The LT5 defies convention... 3" pipes seem to work very well along with the oblong 2" primary header diameter. I would like to try out a 1-7/8 set of longtubes, but seeing as how that's about the same size as stock, it is obvious that this engine is a little unique on tried and true hot-rodder dogma doesn't strictly apply.

Given that, I'd probably prefer to run the metric sized stock pipe which is right at about 2.7" diameter (which in itself is a clue that GM knew 2.5" was too small). My 5.0 mustang and LS3 cars both have pipes smaller than that and make similar power at similar revs, but the LT5 just seems to like the big pipes and i can't totally explain it. If anything, it moderates the torque at and below 3500 rpm making it a little less likely to spin off the rear tires on the roll. Also, the ZR-1 has never been the king of 60 ft times - it's all about the top end and not having to shift as much.

[XfireZ51]

I agree w you there Mike. As an FYI, my stock block uses 1 7/8" primary tube Watson headers. Not sure the collector is even 3" but it all dumps into 3" pipes, no cats, from there to the 2 outlet DynoMax muffs. My torque peak, 402SAErwtq/411 actual, peaks at 5200rpm. Of course we are talking about a stock block 5.7L but ported heads, TB, and top end using both intake and exhaust cams. I think the "lack" of low end torque has more to do w the characteristics of 4V motors and less to do w the exhaust system diameter. For me, I'd rather trade that low end grunt for what happens once the car gets beyond the 1/8th mile.

[edram454]

To each his own. seems to me that there is a reason why GM did not run 3 inch exhaust in the zr1. they probably thought they would have tons of complaints from the customers of the new zr1's complaining as to why the lt1's were smoking them off the line and why they had to rev up like a ricer to make power. My experience with too big of an exhaust proved it to me. In the end, I wound up selling that sweet 1971 mulsanne blue big block coupe because I just was not getting the torque I should have been getting from a healthy 468 big block. I didnt want to spend another 2500 for new smaller diameter side pipes so I sold it. I wish I kinda had it back again. That car was completely restored and won lots of trophies. After that car I stopped being a waxer owner and became just a regular owner.

ed ramos #3028

[bradley]

my black 90 has run 119.47 in the 1/4 with a 21/2 in drgas system and spin tech mufflers . the car only has plenum and injector housing porting headers, and a tune. wish I had the time to switch it to the 92 and see what the difference is.it has a 3 in system with a xpipe and super turbo mufflers callaway porting which is suppose to inc the heads and has only run 118.10 as the best mile an hr .both run about the same et.makes one wonder what is the best way to go ???????

[Schrade]

my black 90 has run 119.47 in the 1/4 with a 21/2 in drgas system and spin tech mufflers . the car only has plenum and injector housing porting headers, and a tune. wish I had the time to switch it to the 92 and see what the difference is.it has a 3 in system with a xpipe and super turbo mufflers callaway porting which is suppose to inc the heads and has only run 118.10 as the best mile an hr .both run about the same et.makes one wonder what is the best way to go ???????

So do we!!! That would be VALUABLE info.

Unless Ed has before and after dyno graph info here....................

Does Marc have dyno graphs on his site? I haven't see any info there...

[edram454]

no i dont have dyno graph info on my corvette or my old fox mustang. where i really noticed it was with my big block 71 corvette going to the super-competition hooker sidemounts killed low end torque in a torque monster like a 468 hydraulic cam big block coupe. I did have supertrapp mufflers on my fox mustang and I had something like 20 spacers just to drive around on the street but when I would go racing I would remove all spacers and the cap and run wide open exhaust. my exhaust was 2.5 at the header flange into a 4 inch pipe then into 5 inch super trap mufflers. but at 1200 hp it needed that. My big block corvette definitely felt like it had more torque before the header install. I am not surprised that bradley's 90 ran such a good mile an hour with 2.5 inch exhaust. If he had 3 inch he would probably have a slower 60 time unless he drops the hammer at 5k rpm which would only blow the tires away or chew up some u-joints.

I know that the ex-owner of my car said the few times he went to a track day that a buddy of his who had a 368 lt5 stroker, could not pull away from him on the straights at all and that surprised him. the only time his buddy would pull away a little is when they were coming out of a turn because his friend had 4.10 gears in his z and he had the stock 3.45. Sometimes these cars are like fine wine, some just have the right tweaks and runs like a bat out of hell while some have the wrong combination of tweaks and runs normally but not like one anticipates it to run. On another note, we know that each of these z's were dyno tested before leaving bowling green and I am sure, for whatever unexplained reason, some cars ran better than others which is why they wont release those dyno sheets.

[TomZR1]

I agree with Ed I think 2-1/2 is perfect for the z just wondering if I will lose any torque with headers? I know everyone saying you will get around 20 hp

[TomZR1]

That's why I went with those discontinued hard to find flowmasters force11,plus love the look & I'm sure they'll sound awsome!!!!!

[edram454]

you will not lose torque with the headers. your 2.5 inch exhaust system will have just the right back pressure to insure your torque stays around to do its work. its those big pipe systems that will not supply enough back pressure and the engine having to rev more to produce the backpressure it needs to have the torque. headers and flowmasters without cats and the resonator is perfect. It will last forever and the sound will be great when you are on it and nice when you are just cruising. no tinny sound out of the flowmaster system.

[TomZR1]

I will post pics when done,as for headers can't find anyone to install them here in Michigan once I get em.any one know of anyone in Michigan ?

[TomZR1]

I know what you guys are thinking ,install them your self ,hell no it looks like a pain in the azz,not going to start something that i can't finish.

[TomZR1]

got my exhaust,they look awsome!!!!!!!!:-D

[Schrade]

I know what you guys are thinking ,install them your self ,hell no it looks like a pain in the azz,not going to start something that i can't finish.

I think you can do this with 1 hand. If you we're gonna' do the PS hoses, you can do the pipes...

[edram454]

they look great!! You will love these and they will tuck in nicely under your car. Congratulations on your purchase.

ed ramos #3028

[project c4]

got my exhaust,they look awsome!!!!!!!!:-D

If you don’t mind me asking... what diameter is the y-pipe where it goes into the resonator ?

[TomZR1]

Don't know, I'll measure & let know

[project c4]

thank you sir

[TomZR1]

11inches

[project c4]

thank you very much :cheers:

[Tony Davila]

George, this is exactly what I went through. Primarily Corsas over the years but just got tired of the Loud. I have headers, no cats and last year had Marc reinstall my stock '95 system from the headers back. The only difference is I had him add electric QTP cutouts and I installed a rocker switch hidden under the carpet on the right side of the console. The only issue is I had to sacrifice the spare tire carrier. On longer trips away from home I carry the spare in the back. I added small tips to direct the exhaust to the side. So far I like the setup a lot. It is stock quiet when I want and when open I can scare children and pets and set off car alarms. I normally run slightly open for a little rumble.--Bob


This what is inside of your stock mufflers. Just in case you or anybody else was wondering. 2.75" shrinks down to 2.25" at the outlet. No wonder muffler swap gains good power improvement. I'm doing the same mod with my B&Bs.
http://i69.photobucket.com/albums/i66/Zrace1/C4LT1muffler_zps25a6482c.jpg

[Karl]

11inches

How large is the inlet pipe where the two pipes meet and enter the resonator... 3.5"??? Can't be 11"

[We Gone]

How large is the inlet pipe where the two pipes meet and enter the resonator... 3.5"??? Can't be 11"

Just checked mine, 3.5" across, 11" if you wrap the tape around the pipe.

[Schrade]

How large is the inlet pipe where the two pipes meet and enter the resonator... 3.5"??? Can't be 11"

I knew project c4 wasn't interested in circumference...

If Tomz pipe gauge is uniform (not likely) where he measured it - oval or circular, then the inlet is about 3 1/2", MINUS pipe gauge x2.

Website for his hardware might show guage.

We need to see the tape on the pipe.....................


ed.:
Know the thickness of your pipes Steve?