Which headers?

[Schrade]

While the car is at the 'speed' shop, I'm pondering headers, since I'll be 'hands on' as repairs are effected here.

Which brand are the easiest install? As in 'drop in'?

I don't keep the hammer on the floor - mostly light pedal. Which brand is suggested here?

Only other thing to consider is some modest intake work in the near future - porting most likely, and perhaps putting a can opener to the K&N box up front there...

And I've asked this before here, but missed responses if they were posted; what are the airflow bottelnecks in a '90 LT5? Intake? Exhaust? No mods now, except Marc's memory / calibration module in the ECM..............................

What brand do you have in yours?

[Dynomite]

What brand do you have in yours?

Stainless Works on 91' and 92'

SW Group Buy (http://www.zr1.net/forum/showthread.php?t=19910)

SW headers ZR1CORVOR
SW exhaust ZR1CHAMSW

Installing Headers (http://forums.corvetteforum.com/c4-zr-1-discussion/3005470-tech-info-lt5-modifications-rebuild-tricks-500-hp-5.html#post1581825195)
Installing Engine In ZR1 (http://forums.corvetteforum.com/c4-zr-1-discussion/3005470-tech-info-lt5-modifications-rebuild-tricks-500-hp-5.html#post1581825199)

http://i287.photobucket.com/albums/ll142/dynomite007/C%20Engine%20LT5/bb9babbf-fe78-48d4-9719-8a19a11feab3.jpg

perhaps putting a can opener to the K&N box up front there...


Stainless Steel Air Box and Air Filter (L98 and LT5) (http://forums.corvetteforum.com/c4-zr-1-discussion/3005470-tech-info-lt5-modifications-rebuild-tricks-500-hp-2.html#post1581460762)

[Paul Workman]

The 90 LT5 has the most to gain from porting the top end. The primary runners are 33mm compared to 34.5 (about) for the later 93s and up. Also, the primary injectors are sealed at the top of the injector instead of at the bottom. This allows you to remove ALL of the shroud on the primary side injectors -making the 90 IH thee ideal year for top end porting.

The starting point for most top end porting is approx. 36mm. There are nuances that improve over that (but Pete n Marc each have dibbs on one of my family jewels, should I divulge a sacred FBI secret[-X)

As far as port matching into the heads, I believe there is merit to tapering the port all the way down to the valve guide. But, there is some real concern for "punching through" if you don't have a road map, and pulling the head(s) means pulling the motor...not a cheap or easy thing to do.

P.

[Corbusa]

I have new OBX headers waiting for my lazy AZZ to install. I have wondered if the SW are better ? I have heard that the OBX needs to be dimpled near the steering box. If the group buy got the SW headers cheap enough I'd probably go that route and sell my OBX ( just thinking out loud.) Not to change the thread but also since the OBX need to be dimpled I wish someone could show where and how much . This way I wouldnt have to install twice.
Dude here locally that has a ceramic shop will coat the headers for $175.00..
Good question and timing Schrade. thanks

[sammy]

i like corey hendersons headers alot better than the stainless works which i took off my 92 to put coreys on .they are a copy of the jeal headers which i have on my 90 .

[boostedmaxPSI]

I have SW coated which Corey installed and tuned. If I could do it all over again I would go with Corey and support a local vendor. I was impatient.

[Fully Vetted]

Really? Not happy with them or is the extra cost not worth it?

[efnfast]

I wrote myself a big note. "Buy Coreys headers". Then the dollars signs took over and went with OBX. Hope this wasn't a really big mistake.

[FU]

No need too dimple the header's.

When there is a need to dimple the header's. The engine/trans need to be centered properly in the car.

And if I need another set of header's I'd get them from Corey , why ? Because he's Corey and he builds superior.

[boostedmaxPSI]

Really? Not happy with them or is the extra cost not worth it?

100% satisfied. Very good product. Would have preferred to support a local vendor. Plus Corey is just a great guy. I don't know anyone at SW.

[Corbusa]

I thought I read where a few Gents. had to shim the engine or dimple the obx headers . Correct me if I am wrong.. I too would rather support a local guy. Does anyone have the picture of Coreys headers or cost etc?

[Karl]

I am leaning towards purchasing the OBX headers also. I do not see why the others charge so much for LT5 headers since they are all made of the same stainless steel material.

[boostedmaxPSI]

I am leaning towards purchasing the OBX headers also. I do not see why the others charge so much for LT5 headers since they are all made of the same stainless steel material.

....and there's the difference. Not the same material at all. More specific it's the thickness of the pipes that are not the same. I watch one of Corey's guys make one of their headers. It is a time intensive process.

If you are interested in Corey's headers I would encourage you to get a quote. I will say I paid much more for my SW then what Corey quoted me. Again, I was impatient.... And it cost me. However, I am 100% satisfied with my SW headers. Amazing sound and I did improve my rwhp by just under 30hp with a hot motor. Not too bad.

Hope this helps.

[Karl]

I looked on his webpage and could not find out about the LT5 headers.

The OBX I found out about:

1990-1995 Chevy Corvette ZR1 LT5

(2") primaries
(3") slip fitted to stock
(16) gauge runner wall
(2) o2 sensor ports
304 stainless steel
CNC Machined 3/8 inch Thick Flange
CNC machined
Mandrel bend for smoother flow
Individual port designed
Backed by OBX warranty

[mike100]

I'm in the process of installing a used set of mystery headers (2" primaries). Previously, I ported the intake. The intake work was probably good for a little mid range torque gain, but the headers seem to be the key to getting the big rwhp improvements in conjunction with the intake work.

[Fully Vetted]

100% satisfied. Very good product. Would have preferred to support a local vendor. Plus Corey is just a great guy. I don't know anyone at SW.

Oh, yeah. I totally get that. Had my car not come with SW's I def would have gone with Corey. And he is absolutely a class guy. I thought at first you were having an issue.

[Corbusa]

Will Corey be at BG?

[USAFPILOT]

I like my SW headers, installed by me. Though I need to make a drive out to Corey's for a tune. It has been like 2 years since I put them on and I still haven't.

[Corbusa]

Schrade I reread your post and thought I'd add. To go along with my headers I bought dynomax mufflers #17228 and will be using the factory exhaust since its 2 3/4, It should breath just fine. I'll change out the resonator to an X pipe. and today I made some brackets for the mufflers before taking them to have the ceramic coating installed. ( I want to try and use the factory type hangers)The X pipe will be coated as well.

[Schrade]

I am leaning towards purchasing the OBX headers also. I do not see why the others charge so much for LT5 headers since they are all made of the same stainless steel material.

Welcome onto the boards there...

-----------------------------

What work do you have in your top end there, boosted, to get the extra twist in the rear wheels???

....and there's the difference. Not the same material at all. More specific it's the thickness of the pipes that are not the same. I watch one of Corey's guys make one of their headers. It is a time intensive process.

If you are interested in Corey's headers I would encourage you to get a quote. I will say I paid much more for my SW then what Corey quoted me. Again, I was impatient.... And it cost me. However, I am 100% satisfied with my SW headers. Amazing sound and I did improve my rwhp by just under 30hp with a hot motor. Not too bad.

Hope this helps.

------------------------------------

and is header wrap beneficial?

With no portwork up top (yet), and exhaust gases not pushing capacity, the gases would cool quickly, and cooler gases are heavieir to push out the back...

:confused:

[Hog]

These headers on Tepepmeie's 703hp 427 LT5 are the best appearing headers for the LT5.
Quote from said member I believe they are ex-Baker racing headers from the road racing program in the 90's. Had them re-coated this year. 2 in. primaries / 28 in. long. They fit in a C4, I had them in my 91 previously. Torque is improved over the standard Watson/Jeals.

These headers supported 703 on the engine dyno, or 640 rwhp on the chassis dyno,corrected.

http://i1202.photobucket.com/albums/bb373/Paul_Schermerhorn/rossheaderback.jpg (http://s1202.photobucket.com/user/Paul_Schermerhorn/media/rossheaderback.jpg.html)

http://i1202.photobucket.com/albums/bb373/Paul_Schermerhorn/rossheaderfront.jpg (http://s1202.photobucket.com/user/Paul_Schermerhorn/media/rossheaderfront.jpg.html)



These headers would provide for power increases in a narrow rpm band because of their equal length, or near equal length primaries, the other headers I have seen have unequal length primaries lending themselves to a more broad power band.
I could be argued that unequal length headers could be better for a street car, and vice-versa. Certainly ANY sort of tubular exhaust header is better than the stock manifolds.

I would love to see some video so we could here the idle of that car once he gets her all tuned up. Heck even untuned, I love to hear a clip.


Stainless Works LT5 headers (both)
http://i1202.photobucket.com/albums/bb373/Paul_Schermerhorn/stainlessworks.jpg (http://s1202.photobucket.com/user/Paul_Schermerhorn/media/stainlessworks.jpg.html)
http://i1202.photobucket.com/albums/bb373/Paul_Schermerhorn/stainlessworkslt5.jpg (http://s1202.photobucket.com/user/Paul_Schermerhorn/media/stainlessworkslt5.jpg.html)
OBX LT5 header
http://i1202.photobucket.com/albums/bb373/Paul_Schermerhorn/obxlt5header.jpg (http://s1202.photobucket.com/user/Paul_Schermerhorn/media/obxlt5header.jpg.html)

Here is a Jeal header
http://i1202.photobucket.com/albums/bb373/Paul_Schermerhorn/jeallt5.jpg (http://s1202.photobucket.com/user/Paul_Schermerhorn/media/jeallt5.jpg.html)


peace
Hog

[FU]

Lovin those 2" primary's !!

[Karl]

Thank you for the welcome.




Welcome onto the boards there...

-----------------------------



What work do you have in your top end there, boosted, to get the extra twist in the rear wheels???



------------------------------------

and is header wrap beneficial?

With no portwork up top (yet), and exhaust gases not pushing capacity, the gases would cool quickly, and cooler gases are heavieir to push out the back...

:confused:

[USAFPILOT]

These headers on Tepepmeie's 703hp 427 LT5 are the best appearing headers for the LT5.
Quote from said member I believe they are ex-Baker racing headers from the road racing program in the 90's. Had them re-coated this year. 2 in. primaries / 28 in. long. They fit in a C4, I had them in my 91 previously. Torque is improved over the standard Watson/Jeals.

These headers supported 703 on the engine dyno, or 640 rwhp on the chassis dyno,corrected.

http://i1202.photobucket.com/albums/bb373/Paul_Schermerhorn/rossheaderback.jpg (http://s1202.photobucket.com/user/Paul_Schermerhorn/media/rossheaderback.jpg.html)
http://i1202.photobucket.com/albums/bb373/Paul_Schermerhorn/rossheaderright.jpg (http://s1202.photobucket.com/user/Paul_Schermerhorn/media/rossheaderright.jpg.html)
http://i1202.photobucket.com/albums/bb373/Paul_Schermerhorn/rossheaderfront.jpg (http://s1202.photobucket.com/user/Paul_Schermerhorn/media/rossheaderfront.jpg.html)



These headers would provide for power increases in a narrow rpm band because of their equal length, or near equal length primaries, the other headers I have seen have unequal length primaries lending themselves to a more broad power band.
I could be argued that unequal length headers could be better for a street car, and vice-versa. Certainly ANY sort of tubular exhaust header is better than the stock manifolds.

I would love to see some video so we could here the idle of that car once he gets her all tuned up. Heck even untuned, I love to hear a clip.


Stainlkess Works LT5 headers
http://i1202.photobucket.com/albums/bb373/Paul_Schermerhorn/stainlessworkslt5.jpg (http://s1202.photobucket.com/user/Paul_Schermerhorn/media/stainlessworkslt5.jpg.html)


Here is a Jeal header
http://i1202.photobucket.com/albums/bb373/Paul_Schermerhorn/jeallt5.jpg (http://s1202.photobucket.com/user/Paul_Schermerhorn/media/jeallt5.jpg.html)

OBX LT5 header
http://i1202.photobucket.com/albums/bb373/Paul_Schermerhorn/obxlt5header.jpg (http://s1202.photobucket.com/user/Paul_Schermerhorn/media/obxlt5header.jpg.html)

peace
Hog

my SW headers are the longer version than those depicted.

[USAFPILOT]

http://www.stainlessworks.net/products/headers/chevy-corvette-1990-95-headers.html they will set them up for the air system if you want to pay extra, I did. If I could go back I would just ditch the air system, but I wanted to retain the emissions equipment for resale if it ever became necessary.

[Hog]

my SW headers are the longer version than those depicted.
I added a longer set as well, from Stainless Works.

peace
Hog

[Fully Vetted]

Will Corey be at BG?

No, he will not.

[boostedmaxPSI]

Welcome onto the boards there...

-----------------------------

What work do you have in your top end there, boosted, to get the extra twist in the rear wheels???



------------------------------------

and is header wrap beneficial?

With no portwork up top (yet), and exhaust gases not pushing capacity, the gases would cool quickly, and cooler gases are heavieir to push out the back...

:confused:


See post 37. I outline all that has been. Hope this helps.
http://zr1.net/forum/showthread.php?t=17214&page=4

[Schrade]

The 90 LT5 has the most to gain from porting the top end. The primary runners are 33mm compared to 34.5 (about) for the later 93s and up. Also, the primary injectors are sealed at the top of the injector instead of at the bottom. This allows you to remove ALL of the shroud on the primary side injectors -making the 90 IH thee ideal year for top end porting.

The starting point for most top end porting is approx. 36mm. There are nuances that improve over that (but Pete n Marc each have dibbs on one of my family jewels, should I divulge a sacred FBI secret[-X)

As far as port matching into the heads, I believe there is merit to tapering the port all the way down to the valve guide. But, there is some real concern for "punching through" if you don't have a road map, and pulling the head(s) means pulling the motor...not a cheap or easy thing to do.

P.

This I do not understand; NOT an O-ring seal at the top and bottom??? At the fuel rail, and at the port inlet?

Does FSM have a pic of the setup? Anybody got a snappic here? I suppose I'll see it when I get there, if ever....................

--------------------------------------------

And what's the definition of 'tubular' headers? As opposed to ? headers?

[efnfast]

Schrade, tubular headers are made with tubes as opossed to well, I don't know. maybe someone tried making them out of square stock, or flat stock (wouldn't flow very well).

[Corbusa]

?? USAF is there a big weight difference b/t the headers and factory exhaust manifolds?

[Corbusa]

I also see you have studs in the heads for the headers , Do those come in a kit? size?

[USAFPILOT]

they are lighter...but the manifolds have cats attached to them.

[NVMYRC51]

Sorry to resurrect and old thread but I am header/exhaust shopping. Does anybody have a URL for Corey's shop. I found OBX's on ebay for $500 and some change but I am looking for opinions and observations. This price seemed pretty good.