Hi,
I wanted to get some information on building a nice street/track vette. My 1987 C-4 is all stock except for the 17" rims. I would like to keep the cluster information if possible but if not that's ok. I was wanting to go with headers, a true dual exhaust system (maybe with glass packs) and a nice cam set-up.
Questions;
1) What is the max cam (biggest) that I can run?
2) How much and what kind of crap can I get rid of from under the hood (smog crap and so on. I have no restrictions where I live)?
3) What kind of changes will take place or will I need to do with the computer/OBD-1?
Thanks for any and all info.
Jim

 

cut out the air crap put some more free-flowing exhuast. dink around with openin gup the injection system.

 

Biggest cam you can run with which intake setup? Stock? Modded stock? Superram? Miniram? You must answer this question to get a recommendation.

EGR pipe can be deleted with the header install, with the block off plate put on the intake manifold. AIR can be replaced with the free pulley and its pipes removed/plugged.

When you have the EGR removed it will set a Code 32, have the EGR functions taken out of the custom chip you'll have done for the cam install. No other changes needed except a reprogrammed chip.

 

You need to focus on use, and what will be the main purpose of the vehicle. Too many want max HP, and sacrifice drivability only to realize they gave up more than they wanted too. With a stock intake you can go as much as a Comp 08-502-8 at 218 / 224 .480 on a 112 LSA. it will run on a stock memcal, but would benefit from tuning. Anything beyond this and you start to sacrifice idle, drivability, and MPG really starts to drop off. just my 2 cents

 

You need to build a plan for the car and the mods you want. One important thing to consider is the mileage on the engine. Adding more power will stress the various engine components.

Say the car has 200K on it. I would suggest a rebuild of the engine that focuses on the power levels you want and make sure the components are ones that will handle power increases. Also consider the trans and diff. Is the car an auto or a 4+3?

If you are going to work up to power gains, headers and a true dual system will be a good start. On my '87 I have installed Hedman Elites and the 2-1/2 dual exhaust uses an X-pipe located where the main cat was. I use DynoMax UltraFlo mufflers; these are fairly quiet at cruise speeds, no interior resonance, but at WOT, they produce about 105dB. As a side note, the stock (large) starter is a royal PITA to deal with when installing the headers. Get the small Hitachi-style starter!

My car also has a ZZ4 cam, bored .030 for 355 CID, the plenum, runners, and manifold are port matched, the rotating assembly is balanced, and I have a lightweight flywheel. I have also removed the AIR pump and hoses and the A/C condensor (more for weight saving than caring about cool air...). I also have a set of BOSCH III injectors from FIC.

Right now, I still have the stock chip, but a tune is on the short list. I think the HP is right around 300 at the flywheel and I can easily break my Hoosier A6's loose in 2nd gear. And the car will still get 26 MPG at 65 MPH (4+3 trans and 3.07 gears.

A different gear ratio in the rear end can be another to improve performance, Look at ratios in the 3.30 to 3.7 range; that will improve acceleration and still provide decent MPG on the highway.

And remember: "Speed costs money. How fast do you want to go?"

 

Thanks for the replies. A lot of good info. I took the car to the track last week and ran a 14.4 in the 1/4 at 96MPH cutting the light at .211. I'd like to get into the 12's without having a bunch of computer issues and killing the bank. The intake set up is stock and I have 132k miles on the car. If I go with the Hedman headers, true dual exhaust system with glass packs and a Comp Cam 08-305-8, 220/230, do you think I should get into the 12's with the stock intake system and do you see any other issues?
Again Guy's, Thanks for the info.

 

What was the RPM at the far end and what gear were you in? What trans?

Your ET and trap speed is right where the '87 was when new!

 

I don't know what my RPM was due to the cluster. You can't see the MPH or the RPM unless you are wearing sunglasses. I have another cluster on ordered. I keep it in drive (stock trans 700R4) due to not being able to see the tech and the slip showed 96.42 MPH.

 

Bone stock intake with that cam will not get you 12s. The cam can't breathe with the stock TPI on it.

It can break below 13.0 with a modded TPI intake, but you will also want DRs on it.

 

Congrats on buying the vette. Like C4 cruiser said, speed costs money and you have to determine what exaclty you want to do withthe car. I have an 85 and went through it from front to back and I can tell you that once you modify one thing you have to do something else to make it all work. One thing you got to focus on like the others are saying is getting more air in and out of the motor and freeing up some of the drag. TPI intakes are not big power makers even if ported. I swapped mine for a miniram and that really woke it up. The super ram is another good peice but won't fit under the stock hood which is whyI did the mini.

 

Highly, HIGHLY recommend heat-coated headers to save all that underhood plastic from melting. Guess how I know. I've had good results in a dry climate, with either ThermoTec wrap/paint and ceramic coating; latter preferred.

Did I mention, highly?

 

Superrams fit under the hood of a C4 just fine

A superram, that cam you have listed a 2800 stall you should be in the 12s. 3.45s even better.

Add a good set of heads, port the SR heavily youll be loving life.
one thing at a time, first thing is a good plan that you stick to all the way through .

 

I disagree, there was a test done in Australia that proved the stock TPI design makes more power below 4000 RPM than either of the two mentioned above. As long as a majority of your time is spent above 4000 RPM, or you just feel you need every single last bit of power from the top end then go with one of the above. If most of your driving is below 4000 RPM then why give up more power for a daily driver.

Also, the Superram fits under the hood, but the Holley Stealthram does not.

 

My apologies for passing bad info on the super. I did mean the stealth. I can't speek on the test done you are talking about but I can tell you the tpi was choking my engine even after porting it. Once we swapped to the mini it pulls all the way to 6k which is what I wanted. Just my two cents

 

If I were doing it, I'd go with the mini (sure would like to read that Australia report), trick heads if you can afford them. Cam, coated headers..2 1/2 exhaust, 2800 stall. And as long as I was that far I'd throw in some new rod bearings at least. I wouldn't worry about gears, I've got 3:07 and I really like them. A custom chip and Plan on getting some new rubber too.

And make sure you save all the stuff you take off........mistake I made on my last build.

 

Vettoz is the one who posted it. Basically, if you put a miniram on a stock engine you lose power over stock. With a 218 / 224 on a 112 LSA an edelbrock, or TPiS Bigmouth with oversized runners will produce better numbers below 4000 than the mini, but the mini wins above. The First is a compromise of both. So, for a guy that comes up to a stop sign, and wants power out of the hole without a high stall converter the answer is simple. For a guy that's wants everything he can get, and has no problem going above 4000 the mini should be his choice.

 

A lot of good info. What size injectors should I run with a mid can or are the stock ones OK?

 

Here's where I'm at now. I have remove the stock exhaust and going with Hedman hedders on a true dual exhaust system. I have also removed the AIR pump/system (hoses) and the A/C Compressor/system.
Question; What do I use to in-place of the AIR pump and A/C Compressor for the fan belt (pictures would also help out)?
What size injectors should I run with a mid can or are the stock ones OK?

 

Stockers are fine for a 350.

 

On my '87 with the TPiS AIR pump eliminator kit and a Dorman A/C compressor eliminator, I wound up using a Dayco 5060865 belt. The OEM belt is a 5060885 This is about a 2" difference. It was the AIR eliminator kit that required the shorter belt to be used. The pulley on the A/C eliminator was the same diameter as the pulley on the A/C compressor.

I'm using the Bosch III injectors I got from Jon at FIC. I think they are 24lb but your OEM Multec injectors should work as long as they are in good shape; mine were pretty well clogged up. I have a ZZ4 cam in the engine.