yay! Got my car back together!

[Aurora40]

Got the IH's and plenum on, new injectors, and tossed in the new prom. Filled it up with coolant, and fired it up! It cranked long but then fired right up and idled great.

The slight pulsation at idle didn't go away, but it is really quite mild. I did try to balance a nickel but couldn't get it to stand up. Maybe I need to find a nickel with a less rounded off edge.

The only problems I had were that my MAP bracket got bent and one of the connectors under the plenum got chipped shipping it out. Then putting the car together, one of the PCV metal hoses had that bracket that gets bolted onto the plenum snap. It's still in place fine, but I ordered a new one.

I drove the car lightly up and down the street because it was misting out. It felt fine, but I can't wait for a nice day to open it up!

I replaced the PCV valve cover/top piece, and man does that make a difference. The old one would slide right off the valves with barely any effort. This one grips like mad and was actually pretty hard to install.

:thumbsup:

[Aurora40]

Took it for a spin tonight. It feels stronger for sure. I didn't get to do much flooring it in 1st/2nd, though. But in 1st it would break loose even at 40+mph easily. It used to just scramble and shift side to side at those speeds, now it flat out spins them with the tach shooting up. I need new tires...

That sort of mechanical sucking sound when you get on it is more pronouced. Very much an intake sound when you floor it.

Also, flooring it in 5th at like 60mph feels stronger. Of course it hardly pins you back or anything. But it feels more useable, the car accelerates like if you floored it in a V6 sedan that downshifted. It accelerates quick enough that the speedo jumps digits 2 at a time, and as you get to about 75-80mph the acceleration just gets stronger.

I would believe it made a ~10% increase in power for sure. It's not like some different animal now, but it definitely feels stronger. It always makes me wonder if ~400hp isn't all you need on the street. The car is quietish with the stock exhaust, it pulls like mad, you can break tires loose easy, what more do you need? I almost think some short-tube headers, cats, and a '93+ exhaust would be the way to go for some extra power but not too loud. WHo knows, though, I'll have to check out all the systems folks have at BG and maybe Carlisle to really hear them in person.

I did notice my car didn't idle below 800rpm now. Perhaps that's a function of the chip. I'll see what Mark says about this. It used to idle closer to 650 rpm or so once warmed up.

[tomtom72]

Holy smoke!!! That sure sounds sweet to me but then what do I know.
:thumbsup: Bob!! Also nice to know about the top holder/connector for the PCV's. Guess I should hunt one up so I can loose my Zip Tie, mine slips on & off with no resistance at all. It's proly leaking like stink around the edges!

Let me ask? Ported injector housings + ported plenum + port matching I/H's to plenum + a chip to use with the port job + what else I don't know to ask for from a vendor. Sorry for my ignorance, I'm just trying to not be totally ignorant if I make some calls to vendors that do this kind of stuff.

I had a thought the other day...the later I/H's are different from the 90-92 I/H's. Are the 405 hp I/H's transplantable to an early motor? The later ones are said to flow better than the early ones.

Sorry for being so nosey, Bob! Thanks for any light thrown my way!:thumbsup:

Tom

[Aurora40]

Hey Tom, you could buy the later injector housings. You'd probably need new primary injectors, though, unless yours can still have the o-ring on the end.

However, the 1990-style is ultimately better. Since the o-ring is up at the top in the IH instead of on the end of the injector, if you port it, the entire injector bump-in can be removed. Some little bit needs to be left on 93+ ones for the o-ring to seal against.

I don't know if the 1993+ heads have bigger ports. If so, the newer style injector housings wouldn't be port-matched to your 1990 heads. I think it definitely wouldn't match the plenum. All in all, for ~$300-400 for the housings, it might be better to just have yours ported. The later style plenum is not cheap, they are like $1800 or something.

But I think stock for stock, the 1993+ IH's and plenum would be an upgrade on the 1990 motor. Whether the money makes sense is another matter.

I got the IH's ported, they still match the heads, though. The plenum ported, the TB bored to 63mm secondary butterflies, and the TB extension ported to match and to reduce those bump-ins from the reliefs to fit over the P/S and AC pulleys. And it came with a chip and the gaskets necessary. All the porting was beautiful to look at, the ports are really pushing it as far as being about to join together. And the TB butterflies are absolutely huge. The only part that isn't so pretty is the TB extension. I guess as you cut away there isn't much left. The mounting surfaces for the screws are skeletonized, the screws look like they only make contact for about 3/4 of the surface. And that V'd in area for the top center mounting screw is sort of ugly and jagged ground away. I mean, it looks like nothing was spared in opening it up as much as possible, but in retrospect it's the only part of the intake you can really see, and it's pretty ugly to look at. If I had it to do again, or if the extension wasn't $400, I might have it less hogged out.

One thing I noticed today, is the car seems more tractable at lower rpms. It feels less luggy and slow when giving it gas in 5th or even 6th to pass. I don't feel a need to downshift at all, unless you really want to smoke someone. This may just be due to the new injectors, or maybe due to the porting. It's not like the car is a beast in 5th or 6th at 60mph, but it feels more useable now.

[Z Factor]

I would believe it made a ~10% increase in power for sure. It's not like some different animal now, but it definitely feels stronger. It always makes me wonder if ~400hp isn't all you need on the street. The car is quietish with the stock exhaust, it pulls like mad, you can break tires loose easy, what more do you need? I almost think some short-tube headers, cats, and a '93+ exhaust would be the way to go for some extra power but not too loud. WHo knows, though, I'll have to check out all the systems folks have at BG and maybe Carlisle to really hear them in person.



Now that you have it breathing in better, wait until you have it breathing out as well.:thumbsup:


The only part that isn't so pretty is the TB extension. I guess as you cut away there isn't much left. The mounting surfaces for the screws are skeletonized, the screws look like they only make contact for about 3/4 of the surface. And that V'd in area for the top center mounting screw is sort of ugly and jagged ground away. I mean, it looks like nothing was spared in opening it up as much as possible, but in retrospect it's the only part of the intake you can really see, and it's pretty ugly to look at. If I had it to do again, or if the extension wasn't $400, I might have it less hogged out.



You would not happen to have a pictures of it would you?

:cheers:

[tomtom72]

Big thank you, Bob, for being patient with my Q's. I would say this about your 6th & 5th observations...I still need to downshift in 6th if I want to pass right away so I would say that all your work must have given the results you observe. Mine runs great with the new injectors but in 6th if I want to pass now I must go to 5th. So I would say a marked improvement with your set up is evident.

I was just trying to figure a way to do what you did & not need a place to lay the car up while waiting for parts to come back from a vendor. I can dream...guess I'll have to ask my uncle if I can take over the garage again later in the year so his Mercedes don't sit out in the snow.

Thanks again for explaining to me about the process and the late lt5 parts.

:thumbsup:
Tom

[Aurora40]

Big thank you, Bob, for being patient with my Q's. I would say this about your 6th & 5th observations...I still need to downshift in 6th if I want to pass right away so I would say that all your work must have given the results you observe. Mine runs great with the new injectors but in 6th if I want to pass now I must go to 5th. So I would say a marked improvement with your set up is evident.
Well, maybe I should clarify. Acceleration in 6th won't wow anyone. But the car will accelerate at a rate you can notice. In fact, the speedo was even jumping 2 mph increments by about 70mph in 6th.

But I mean passing like on a multi-lane road. Not like pull-out-to-pass on a two-lane road. No way I'd keep it in 6th for that, probably not 5th either, though 5th might be acceptable if you had some space.

[tomtom72]

I understood exactly what you were saying, non-ported = almost non-existant 6th accleration. Now you can actually feel the improvement in 6th. Ya gotta like them results & the part about 1st & 2nd really got me to sit up & take notice. All in all I see you are impressed & that says that this stuff does work if done correctly and with the limitations in mind that the heads were not done & no headers & exhaust work. I say good luck with the new hp & have fun!:thumbsup:

tom:mrgreen:

[Aurora40]

I should also say, the car was idling normally today. I guess the 800rpm thing was maybe the wiped "memory" state of the ECM, or maybe the cold air, or who knows.

[Aurora40]

You would not happen to have a pictures of it would you?

:cheers:
No, I guess I could pull the duct off and snap one. It's not ugly when you pop the hood, but it's the only part someone could concievably see easily if they pulled the duct off.

It's not really that bad, it's just that it's quite obviously modified.

[Jeffvette]

Passing..... drop it down to 3rd. :D

[Aurora40]

You would not happen to have a pictures of it would you?

:cheers:
Here you go. It was still mounted on the car, though. So it wasn't easy to get a good shot. But this shows you the V part that is sort of jagged. And you can kind of see the skeletonized screw mounting surface on the left.

The TB bores looked huge to me when it was off the car. If you could see the primary butterfly in this pict it would help for scale.

http://members.aol.com/corvettezr11990/misc/TBext.jpg

[Jeffvette]

Going for stock to the 63mm is only a 5mm change or roughly 1/4" . So that gets you a true 2" blade opening.

Good job on port matching the air horn to the TB, most pieces I've seen done, have not had that matching.

[Z Factor]

Thanks for the picture, it looks good:thumbsup:

:cheers:

[tomtom72]

:dancing Man that looks very cool! Sweeeet job that they did, Bob! If the rest of the work was that quality I'd say you have a great combo going!

I'm envious!;)

Good luck with your evolving project!

:thumbsup:
Tom

[Aurora40]

Good job on port matching the air horn to the TB, most pieces I've seen done, have not had that matching.
Heheh, thanks. But really all I did was pack it up and pay the bill. :)

Man that looks very cool! Sweeeet job that they did, Bob! If the rest of the work was that quality I'd say you have a great combo going!
Well, I thought the rest seemed better. Everything else was very uniform and smooth and attractive. I guess I'm the only one who things that jagged V area at the top is kinda an eye sore? It's not a biggie, though. I guess if the car is ever making big power then it will be good to have. :)

[Aurora40]

So I changed out my plastic-lensed Wagner headlamps with Silverstars. I wanted XtraVisions because they are quite similar to Silverstars but last much longer, but the dang auto parts place never stocked them (I checked like 5 times and each time they are like "they should be in this week"). Anyway, I decided to take the car for a spin at about 10:30 to see how they were and make any adjustments to the beams.

As I was driving along, I found myself at a red light on a 4-lane divide highway with a 55mph speed limit, and no one around. The car was nice and warmed up, so I rolled on it somewhat gently up to about 15-20mph to get through the intersection, then dropped the hammer. This car really takes my breath away! It pulls so hard now at the top, it just keeps pulling and pulling. I hit the rev limiter in 1st and in 2nd, and took it up to about 110mph, the fastest I've ever had it on the street. It went through 1st and 2nd so fast that I just had to try 3rd... It's insane!

Probably one of the neatest and also eeriest things is having the car accelerate so easily and quickly, but be so quiet. It has that sort of electric motor sound of a DOHC motor with a quiet exhaust. The intake sound almost overwhelms the exhaust. These cars really sound nice, though obviously fairly restrained.

I turned around at a later intersection and punched it again, and I hit the limiter again in 2nd. I'll have to really pay attention to the tach, it just keeps pulling so easily.

One thing that I guess I find so cool is my perspective. This is obviously not close to the fastest car around. But it's by a long stretch the fastest car I've ever driven or ridden in. My '87 vette was probably the next fastest. It was fun but you could punch it at will. It was fast but really not so fast. The Z almost makes me feel like I have to plan ahead before punching the gas. It's just so quick.

I recall one time driving on the interstate from work to my wife's house (girlfriend at the time). I was in school and worked nights, so it was like 1-2am. A '95ish Supra Turbo was in front of me, and I was going quicker than him. I suspected something might be up, so as I passed him I was ready to punch it. He nailed it, and I punched it and let the 4+3 kickdown to 4 on its own. The guy walked away from me, especially once the overdrive kicked in at about 4500 rpm (it did that if it kicked down on its own, but wouldn't if you manually kicked it down). I raced the guy a few times, up to about 120mph. Above about 90mph, the L98 would really start to slow down. Part of it was the gearing, and part that I wasn't the most aggressive shifter for downshifts (I still am not). But thinking about that car accelerating to 120, and this car accelerating to 110... Wow what a contrast! Only 3 years of 'vette evolution separated them.

Anyway, sorry for the rambling, I was just really wowwed!

[tomtom72]

Now That sounds sweet!! :thumbsup: Bob! So glad you are happy with the results!

I hear ya about comparing these cars to other previously owned vettes, it is something to marvel at the leap forward from an old fashioned sb 350 to an LT5. Man that gap is huge! What was that I read..."it's not the numbers but what's under the curve..." I forget that sometimes when I'm in a hurry and step too hard on the gas in 1st, even if I'm going 20 or 30 mph the car looses traction. I can't concieve of what your project has done to exacerbate that situation! It sure sounds like a pleasant problem to have!

Good luck with your "new" Z! Enjoy!!!

:mrgreen:
Tom

[Z Factor]

Anyway, sorry for the rambling, I was just really wowwed!

I think you will find that we all enjoy reading about others who experience the same thing we have at one time or another. If and when you go the exhaust route, you will be marveling even more at all the available power at the upper end. Our cars just keep on pulling long after others beg for mercy.

:cheers:

[WB9MCW]

it is all about the pull....pulling away as u know the other guys heart sinks and your beats faster with the increasing rpms...it is the luv affair we have for the LT5...the TRUE hartbeat of our american exotic the mighty ZR-1....LONG LIVE THE KING.........................