Hey guys,

I've been reading up on the forrum, looking at bold on mods that people have done, thing they are selling in the Covette Mall items.

Here is what I came up with
I have an 88 vette

cat back exaust 183$ = 10 hp
K&N (already installed)0$ = 3 hp
Air Foil 78$ = 10 hp
Intake air sensor 67$ = 3 hp
repositioning
hypertech chip 270$ = 10 hp
Headers full/short 749$ = 15 hp / 5 hp
Engine Pulleys 210$ = 5 hp
Total: 1287.5 = 61 hp / 56 hp

These prices are in Canadian dollars.
I also put the minimum Horse power gained advertised or by what people have told me on the forrum.

My car has 245 hp stock, would all these mods really make my car up 300 hp.

And is there anything else that would be bolt on that I could do?

 

In my opinion, probably not because the advertised horsepower of some of those bolt-ons is higher than most actually see (like the air foil is not going to give 10 hp). On top of that, the HP claims are typically not cumulative. You'll definitely see some gains, but not the total of the advertised gains.

Good luck!

 

How do you really know how much HP you've gainned after performing all the bolt ons?

do you really have to bring your car in a dyno? or is there some other way I don't know about.

 

We know we gained HP because of Track ET's and MPH, or a dynojet test.

The airfoil does not give 10hp, more like 1hp. Dont waste your money.

They hypertech chip gives almost no hp either, dont waste your money. Do not get a chip until youre done with modifications. Otherwise you may want someone on the forum to burn you a custom chip if you just want the fans to come on earlier. Chip changes dont really give any HP until major modifications are done, like cam/head/intake changes.

Other things you can do on an 88, remove the frisbee from the water pump, its a large weight that was added by GM because of another accessory, but it serves no purpose other than 10lbs of extra mass to get moving. This will free 5-10hp.

Remove the screens from the MAF sensor, there are screens in front of and behind the sensor element that can be removed for a small hp gain. DONT touch the sensor element inside.
Cut open the air lid so the K&N is entirely exposed.
Bypass the TB coolant, mate the two hoses together.

Porting the stock intake will also give some real gains in hp, 10-20 most likely depending on how much porting/siamesing you do.

 

Lets say I was to change my Intake manifold and put a better flowing one?
what kind?
about much would it cost?
What kind of HP gain would I be expecting?

Do I have to change the cam and the Heads at the same time?
or can I wait for that?

do I have to remove the hole engine from the car of simply leave it in there and change the intake manifold?

I've seen a lot of you positng stuff about heads and cam's, but never about the intake manifolds?
Do you leave the stock Trotle body after changing the intake manifolds?

Just trying to learn what type of perfomance upgrades I could do in the future and what would be best.

Thanks

 

There are 3 popular intake manifolds that come to mind: the Edelbrock, Lingenfelter/Accel base, and the TPiS BigMouth. All are good, all cost about $400-500 US. All should give approx 20hp gain, give or take depending on other mods.

You should set a power goal before you do anything serious to the intake. There are a few routes to consider. Run a search on the Miniram and Superram and Stealthram.

You dont have to change the heads and cam to do the manifold. The engine can stay in the car, nothing wrong with doing them now.

Leave the TB alone, sizewise, until you put in a bigger engine, like 383, 396, etc.

 

I read somewhere that the MAF sensor grids is there to make the air flow straight and constant... and removing it isn't a good idea.
"not sure if this is true or not" :confused:

I didn't know we could remove that frisbee in front of the water pump... I've seen it in my engine bay plenty of times and never understood why it was there.

The TB bypass sounds really good also, but I need to get an adapter for the water hoses. I've seen someone use a copper pipe.. I'd rater order something that would make it look more original
I don't want to see a peace of copper pipe under the hood. I've seen a package I could order for like 10 or 15 $ on this web site, but they only advertise it for LT1 engines. Would this fit on my car ?

One last thing.... hp for money, what would be the best investment in HP gain.

About how much would putting high performance head, cam, and Intake cost?

Thanks Dark vader, you rock!

 

The engine was rebuilt 2 years ago, I know it was rebuilt by a very good engine rebuilder in my area.. one of the best.

I know for fact that the piston were overbored to a 383, but not sure about the piston rods?
Would a bigger intake be more logical being my pistons have been overbored?

 

I'd really like to reach 400 hp.

Don't currently have the $ (just finished paying the vette) but I will one day :)

 

The MAF screens are there to straighten the air, but its not necessary, the air comes in straight already. It is proven to help L98s.

You dont need any kits or anything, buy some PVC pipe from the hardware store and two clamps. Or just buy a 5/8" heater hose and route the coolant straight.

At the moment, for the L98, the best money would be spent on exhaust. Headers+catback.

Cost for this stuff varies, Superram plenum/runners $700 then you need the base which is $400-500. (new, but you can get it off ebay cheaper)
Cams are usually $200-300.
The stock heads on the 88 are good, so all you need is portwork and valvetrain upgrades for whatever cam you pick, the work will push $1000.

If you have the automatic, Id get the Superram.
If the manual, probably the miniram, but the Super and Stealth would work on either.
Run the search, youll see some debates on MR vs SR, etc. Read that stuff.

 

If your engine was bored .030" over I believe that would give you a 355cid; if stroked it would be a 383cid.

Check out my site for info on how much HP you can get from various L98 mods; then you can look up the $$ cost of each in catalogues. Also the story of the "frisbee" is on my site. But don't do the chip change till you're done with other mods and see if you realy need it.

In addition you can upgrade your ignition, cut back your spark plugs (on my site) and gap to .045" or more for a real 10hp gain.

You may be pushing it to get 400chp from a 355cid TPI L98 but toss in a TransGo shift kit and a 2,000 RPM TC and you will have a great street/strip Corvette that builds over 370chp and runs low 12s.

After you do cam & heads do the siamese base (on my site) to gain top end breathing with the TPI intake at a low cost. You should then have your shift points raised to around 6,000rpm. If you later go with a super ram or mini ram you won't be tossing much $$ away with your stock intake.

 

Don't spend your money on a high dollar manifold without considering the heads and cam change. If you're comfortable spending 1K plus on a SuperRam to only get 20HP, your money can be better spent elsewhere.

If you don't want to change your heads and cam, get your stock TPI plenum ported and switch to Arizona Speed and Marine runners or equivelant.

Ron

 

My vote for your first question would be an ATI Procharger. For $4k, you could get 100+ HP.

You can easily spend 4K or more depending on what intake that you go with and how wild you get with head work. Don't forget that changing the cam will require some valvetrain components (or rather, it would be a really good idea to change them) like valvesprings, lifters, pushrods etc...

IMHO, the Supercharger would be cheaper especially if you're starting with a stock motor which is what the mainstream manufacturers have designed their bolt on systems for. Check out ATI Procharger, Vortech or Carroll Supercharging for more info.

Ron

 

I understand most of the options I have for modifying my engine now. heads, cam, valve train on the cams, intake manifold, exhaust manifolds, cat back exhaust..... and other small bolt on modifications/removals/adds OR I could simply have a turbo or supercharger installed.
I know I also have to make certain that every thing matches together to make the best performance.

I'm pretty sure I have a 383 stroker in my car and I know this is a good start for performance.... I've never been told 355 by my step dad, witch is the one who had the engine rebuilt by an engine rebuilder in my area. So it has to be a 383. He did mention 0.030 pistons bored and told me it would only coast a bit more $ to have it rebuilt to a 383 instead of the stock same 350.
( I was ignorant back then and didn't know anything about cars)

I know that the tranny has a stall kit, I can tell there's one in there just by the way the car stalls for a bit and lets the rev's go up and then takes off by pressing the pedal to the metal. :)
I don't know what shift point the stall kit has though? Is there a way to find this out on my own? I've seen lost of stuff about 2600 to 3000... does this mean RPM's it stalls before is launches.

I also know the RPM level was pushed up before the tranny shifts... not sure how they did this but I think the trainny was simply adjusted by the guy who installed the stall kit.
One more question, since the engine is a 383 stroker does that mean they changed the cam??? or just the pistons and the pistons rods.... and are the piston rods connected to the cam or is the cam only to controle the exhaust and intake valves?

I honestly love the way the engine looks like, I know it won't look the same if I change the intake manifold to a higher flowing one, but after reading every ones post... the only way I can take full advantage of a 383 is to make certain there there is plenty of air flow and the stock instake has lots of air restrictions.

I'll see what I'll end up doing one day

Thanks for every ones help!


Ps: if you guys have any good web sites that explains how engines works... more specifically to V8's and piston size, cam's, heads, .. stuff like that could you post them.

:cheers: :cheers:

 

About the Frisbee removal.

Will this effect the A/C in any way?
And can I use the same bolts and use washers for the difference in space after I remove the frisbee?

 

no probs with AC. & yes washers are OK.