Lets just say that I wanted to wake up my 90 vert a little bit and still keep it a nice street car. What would be the mods for it? My motor is a L98 with 31,000 miles on the clock.

 

Hi,

I am trying to do the samething on my 87 Vert. At the moment I have the heads off of it due to a bad head gasket so that is where I am starting.

I am looking at new heads or porting mine not sure which will be cheaper. If my research is correct my heads are currently the 128 cast being an 87, I think yours' are 113 cast but please double check as my memory fails me often.

Regarding the heads; haven't decided how radical I will go but am thinking 64cc 190 - 210 flow rates, 2.02 / 1.6 valves. I will also do roller rockers not sure if 1.5 or 1.6 probably 1.5 still researching.

The next thing I am doing is porting my plenum, I found a shop in a different thread on this board that does porting and polishing of TPI systems. I will port the plenum to 52CC's, the runners I am not sure what I will do there. Ebay has Hi-Flo runners for a little over 400, but really don't want to pay that much; same is true for a Hi-Flo base intake as well. I also found a complete TPI Intake system from FIRST FUEL INJECTION for about 1000. So more decisions to be made.

Next I have already removed the smog pump with a TPIS delete kit, that was a pretty easy 2 hour job and was inexpensive. The next modification due to component failure were the CATs, they have been removed and true dual exhaust now flow incredibly well. That alone woke the car up substantially and made it much more fun to drive.

Finally, since my heads are off I am removing the factory headers and egr components and going with an aftermarket set of ceramic shorty headers I found on ebay for 170 bucks.

The only other item I may need to change will be my pcm, which I will have a chip burned that has an egr delete and probably go with vats delete as well.

I am ultimately going to do a 383 but it isnt in the budget right now so I am trying to select components which can easily support the larger lower end when the time comes.

Best of luck and please keep in mind I am a very much shade tree mechanic so I may find certain things I am doing will not work but most of what I am doing I found here in other threads just not the same combinations. Oh yea, I am opting not to do a cam at this point because the motor is still in the car and I really dont know what cam to go with, CAM discussions seem to be like political or religious discussions everyone gets passionate about them so that one I will wait until the 383 lower end is acquired and just work with it. However i will say the L98 vette motors are Hydraulic Roller cams not Flat Tappet so if you decide to do a cam keep that in mind.

Depending on how much you change air flow you might need larger fuel injectors and an adjustable fuel pressure regulator. I am hoping I don't need to do that right now as my budget is getting stretched and I really miss driving my vert.

Best of luck...

 

Cup of coffee and turn the key on!

If that doesn't do it for ya (and/or get a laugh), replace your entire exhaust and change the gears. Leave the motor alone...it's still too "new". (Do pan/v-cover gaskets if necessary)

 

Thats a good Idea, A cup of coffee and turn the key. My car already has the cat removed with 3in SS tubes that sounds great. So I think that I can afford a small cup. LOL
Thanks guys

 

It costs less than 200 more to do than a 350. Most times half that

Porting the stock heads will never ever come close to what the good aftermarkets do. youll be lucky to squeeze 220-230 cfm out of those without a bunch of hacking and large valves. Not worth the $ spent. Stay away from the Chinese ebay heads.

t. Plenum by itself ported wont do ya much regardless of a few guys claims out there.

Just finished up an aftermarket base, bang up job on some SLPs (polished too) and a plenum. He was in it a whole lot of money.

 

No secret there; more power==more air & more fuel.
Here are a few (relatively) low $$ mods:
Open up the exhaust a little more, ie maybe hi-flow cat-back.
Cut open the air filter & add a K&N filter.
Remove the frisbee from the WP pulley.
Install OEM spark plugs with cut-back electrodes (cut back the ground electrodes to edge of center one).
Do the TB coolant bypass to cool incoming air.
Add an AFPR and bump fuel pressure a little to match increased air flow.
Install a 160 deg T-stat and a manual fan sw.

If you have an A4 you could consider a TransGo shift kit to add a little "snap" to the gear changes.

 

Cam and a tune!
Nothing exotic, just a nice bump up from the stock.
The car will run and sound much better.

 

That might be true if I was building a motor, but I have my existing short block which is in good shape which means I am not spending money there. To build a 383 I will need a lot of block work, boring, clearance, and then crank, rods, pistons, rings, that is surely going to cost more than 200. I am guessing to get my block dipped, bored, clearanced and assembled I am looking at 1500-2000 including parts for the short block. As it stands now I am looking at roughly 1500-2000 for the top end by the time I do the heads, intake, and other odds/ends.

 

Jim,

I just noticed your in Groveland, I am right down the road from you. Maybe when I get my car running again we can meet for a cup of coffee?

 

Yes the big city of Groveland, And yes again I'm always ready for a cup of coffee.

 

My gears in my car are 3.33 now. What will I be looking at if I change to 3.54s? My car is a 90 6 speed

 

Got it. Nice set of heads/intake would sure help. Cam of course but sounds like you dont want to dig that far. Worth it but not a fun job

If you can port heads yourself youll pick up some....paying someone not worth it was what I was getting at.

The intakes usually dont give back what youd think but it sure is better than stock.

 

Here it is. The new Lunati cams are leading edge stuff.
Give them a call and they will set you up with what your looking for.
http://www.lunatipower.com


Unless you are going to go wild your stock heads will work just fine.

The 6 speed will let you be more flexible with your cam selection.
Might consider the hottest cam you can run with a stock automatic.
Nice lope smooth power and good gas mileage still.

Ralph

 

If you're willing to go part way, I'm going to say AFR180's, TPIS cnc'ing of your 113 heads, or TFS175) heads -- even with a stock cam -- would go along way to waking things up. (The later two are good for their smaller chamber size -- with a 350).

At the very least, large bore tube (even a FIRST) intake would be necessary to get that extra air inside. Superram would be good too.

No need to go with anything revving higher using the stock cam.

An upgrade from 3.33 gears would get you thru each slot of your ZF6 faster, but you won't be able to rev up as high as most who wind it up with gears. 3.33's aren't really a bad set for a torque (long-runner) intake. As such, I say skip the gears and do your heads/intake.

Since it's an L98 (with notoriously bad exhaust), a set of headers (even if 1 3/4" shorties) will help. Increase all piping to 2.5" with high-flow cats/mufflers. (1 5/8" long tubes are good for your application too. OBX might be my first choice in your shoes...).

With $3k-$4k, you can get started.

(FWIW, I'm thinking that gets you 50-75 rwhp/35-50rwtq higher. Depending on what you did.)

Of course a tune will be required. So...mods aren't cheap. Coffee is tho!

This is the most you can get w/o cracking into the motor.

 

I have a set of brand new headman long tube headers, they have all the stuff on them for the AIR system $350 plus shipping, they are close to $500 new