gazskiman1

I own an 88 with an L98 with TPI. I have had some work done on it which includes:

A cold air intake
Hooker Super Competition headers
Borla Exhaust
Upgraded fuel injectors (24ib) and fuel regulator
Custom programmed chip, programmed for the work already done.
Car has been dynoed at 290 hp and 372 lbs torque

I want to replace the camshaft to get the car to 350-360 horse without replacing the TPI setup. I know the TPI has its limitation but would prefer to keep it.

I would like to find out if anyone has any recommendation for a camshaft to use, or if anyone has already done something similar to what I want to do.

Thanks in advance for any input.

mlm0

Question about your headers. Did they fit easily without much modification

gazskiman1

I had them installed at a shop but I've looked at everything and it looks like there was very little modifications that needed to be done. I did not lose any clearance under the car. The only modification I saw was that there was some kind of valve attached to the exhaust manifold (I believe its referred to as a check valve) which has about 18 inches of metal tubing. This was removed when the exhaust manifolds were taken off and a bypass was put in place that goes into the header.

K87ZZ4

I'm not sure how much help this will be, but I put a ZZ4 in my 87, added a custom chip, kept the TPI and it works. So, it can handle at least that much cam.

gazskiman1

Thanks, what kind of performance gain did you get from doing it?

vader86

With a TPI or TPI-like (modded runners/plenum) intake, too much duration on the intake side really won't help you. I would not go bigger than about 210-212 degrees @050" on the intake side. Some more on the exhaust side is OK.

So the popular Accel 74211 or TPiS ZZ4 cams are better suited to this, but you can find many others.

You will want the chip redone after this modification is completed, so if you are going to do other things to the intake, then they should be done at the same time. The engine will run fine without the chip done, but I recommend you do it anyway.

gazskiman1

Thanks for the info. I was at a car show and got talking to someone who recommended using a 151 Cam said it was what was put in the 350/350hp engines. Have you heard of this and if so what is your opinion on how it would work in an 88 vette?

Churchkey

Grats you removed one of the major l98 choke points the exhaust manifolds.

Look at l98 dyno charts the HP begins to flat line around 4200 rpm & 250 HP = the engine is suffocating.

Suggest a good intake before a cam. Stock heads are also on the small side port data is available on line.

Suggest adding a cam after the top end is sorted.

Good luck.

vader86

Disregard all power numbers that come from crate engines and the like, only trust numbers that come from engines with your TPI intake system.

These engines are rated with carbs on top, TPI chokes the hell out of them and they do not make that advertised power.

But to your question, I do not know of the '151' cam off the top of my head.

cv67

GM used a different rating for power..that 151 cam in todays world is more like 290-300hp out of a 350.... Probably the same mentality that actually thinks camel hump heads are great, too. Same with buying "big" parts not for a build later on;so in the meantime you got a pig

If youre married to a flat tappet, TPI intake and can port heres what Id do(keep in mind this is the "cheap DIY" mentality)
Port the snot out of the stock base;spend enough time you can easily pick up 30+cfm
Take a used set of aftermarket runners get rid of at least the first half of the divider wall go after the rest til youre about to bust through
Most 256-264 type cams will work fine
Do what you can wiht the heads, a 170-180 cc head that is strong up to about .500 lift is fine; a 194 intake valve is fine

Youll only get so much out of it but wont cost a fortune if you DIY can pass smog and will be plenty of fun. TPI hp #s will always be low its tq youre after dont worry about your hp # it will be what its gonna be

At least you wont be embarrassed by a V6 Mustang

Yariv

Sorry to dig this post from the grave. are the heads stock? 290hp in engine dyno?
Vader86 wrote: " ...210-212 degrees @050 " cam . I have a stock heads and cam in my 85, I just sent my plenum an intake to port match the AS&M runners.
Any suggestion for a cam? I'll dyno my car after the intake replaced. Then I know if I go nothing/cam only/cam + heads.

Thanks

GregMartin

I have.a Crane Cam Z-256-2 in my 84 and a set of Edelbrock ED5089 heads. It’s a bit different because it’s a crossfires with a renegade intake but that cam and heads certainly livened it up. I reckon that cam would work in a L98 as well. The L98 would benefit some better heads as well anything with 180cc intake port volume And 64cc modern style combustion chambers would be a good upgrade. I also have 1.6:1 roller rockers to give it a little more lift.

vader86

You would need a similar size/duration to the 88, but it needs to be hydraulic flat tappet instead of a roller cam he can use.

Unless you want to get a kit and convert the 85 to a roller setup.

Really you would need to do something with the 85's '624 heads, those really choke the engine.

KyleF

Has to be, if not it is wishful thinking. No Chip/Headers L98 is putting that much to the wheels. The exhaust and CAI is not adding much.

The TPI just doesn't RPM well so it can't get good calculated Horse Power. What it can do is make low end torque. Cam should be treated a bit like a "blower" cam since the tuned runners make a ramming effect into the engine, but the ports are tuned to do this at a certain RPM. There is not magic Cam and Tune that is taking a 290hp engine to a 350hp engine while setting under a TPI. With Porting, and runner modifications, your can exchange some torque for horsepower and then swap cams and maybe get there.

The Cam I would suggest for a near stock L98 would be on the order of a 206/214 on a 112 or 114 LSA. With runner modifications like a set of SLP's, I would lookk at possibly going up to a 210 duration on the intake.

Tom400CFI

Correction: midrange tq. L98 doesn't make a meaningful amount more or less "low end" tq and any other 5.7ish liter EFI V8.

BuckeyeROC

Does Lingenfelter still make the LPE211/219 cam? I had their 219/219 in my SuperRam/AFR 190 headed IROC and it was fantastic for the time (almost 20 years ago).

GregMartin

Thats why I suggested the Crane Can Z-256-2
Hydraulic Flat Tappet, Lift 0.432 / 0.459 in, Duration 256 / 268,, 206 / 218 @0.050, 112 LSA, 1200 / 5200 RPM, Small Block Chevy. But anything in their catalog between the 2030 and the 2040 would do the job and still work with the standard ECM and tune (although a tune world help). Lots of early C4 guys have used the Crane Cam 2040 over the years and are happy with it. I think the Z cam offers a bit more with less of a trade off. But that’s of course my humble opinion. Also you can up the lift a little with 1.6:1 rockers.

c4mo

I ran a lunati voodoo 60101k with good result and it won’t be hard to tune.

cv67

So have I, excellent TPI cam makes tons of toruqe.
That 151 cam is a pos I dont know why guys recommend old garbage like that

auburn2

Is the TPIS super L98 cam any good?