Hey all. I have an '87 L98 automatic. I've done the usual bolt-ons and even paid for a scam or two. Right now, here are my mods:

Changed rear from 2.59 to 3.04
Hypertech mild chip
Removed precats
high flow cat in the center
high flow mufflers
Open face airbox with K&N filter
Removed screen mesh in MAF
Air foil in TB... (insert laugh here)

Is there anything else bolt on or under $200 that would give a boost in power or torque that I will feel? I'm going to the show in Carlisle, PA on the 30th and might try to pick up some goodies.

Thanks!
Mike

Personally I'd say save your money.

Why did you remove the screen from the MAF?

Is there anything else bolt on or under $200 that would give a boost in power or torque that I will feel?Mike

If you can turn your own wrench, a cam.

You can get Hedman headers from Summit for around $150, you can't beat that.

Why did you remove the screen from the MAF?

While the mesh doesn't look like much, it restricts the air flow. So, I (very carefully) took the mesh out. If the air filter is doing its job, the mesh shouldn't matter. I did notice a tad of a difference. It didn't cost anything and took 5 minutes, so I figured "why not"?

Hmmm - I've never done a cam, but I'm not afraid to turn a wrench and I have the shop manual... Suggestions? And can I use the stock programming with my Hypertech chip?

Thanks!
Mike

You can get Hedman headers from Summit for around $150, you can't beat that.

I just checked them out - that's a great price for the headers. How are they? Do they bolt right up? I'm not into numbers on a dyno, I like to feel the gain. Can you feel it? :-)

I just checked, it says modification the AC bracket is required. Also, it doesn't appear that it will mate to my current front Y pipe. How did you get around that?

Thanks for the info guys!
Mike

While the mesh doesn't look like much, it restricts the air flow. So, I (very carefully) took the mesh out. If the air filter is doing its job, the mesh shouldn't matter. I did notice a tad of a difference. It didn't cost anything and took 5 minutes, so I figured "why not"?




But isn't that mesh the actual sensor that monitors the air flow coming in that sends the signal to the ecm for A/F adjustment?
I wouldn't think that the mesh would obstruct air flow that much

But isn't that mesh the actual sensor that monitors the air flow coming in that sends the signal to the ecm for A/F adjustment?
I wouldn't think that the mesh would obstruct air flow that much

No, there is wires inside that monitors the air flow, the mesh was just fashionable in the 80's, its coming back though, people are putting mesh in the side vents to keep the mice out I presume.

Oh for cheap mods put on some under drive pulleys, about $160, and you will need a new belt, and you could get one of those air pump eliminator pulleys for $150. Relocate your temp sensor to the air filter housing $40. Coolant bypass for the TB about $14. Shift kit, that will make it feel faster(harder shifts).

My guess is you will reduce your 0-60 by .3 seconds:thumbsup: Mostly due to the under drive pulleys, they say they are good for .2 seconds.

If you're reasonably good at wrenching, replace the camshaft. You can get GOOD ones for well under $200. A camshaft is the BEST bang for your buck, and it only requires taking out a bunch more bolts. I would venture to guess you could change the camshaft in about 2 days time.

I just checked them out - that's a great price for the headers. How are they? Do they bolt right up? I'm not into numbers on a dyno, I like to feel the gain. Can you feel it? :-)

I just checked, it says modification the AC bracket is required. Also, it doesn't appear that it will mate to my current front Y pipe. How did you get around that?

Thanks for the info guys!
Mike

I didn't need to mod the AC bracket, but I did need lenthen the alt brace. They bolt right up, but you will need to weld the collectors to the Y pipe, or you can get a dual exhaust from one of the venders, that's what I did.
You will feel a difference! Easier than a cam change aswell.

I just checked, it says modification the AC bracket is required.

Exh mods are the best bang for $$ you can do on a L98.

The A/c mod refers to the fact the flat header plates do not have the stock style tube extentions on the mounting bolts.
Easily solved by using a piece of tube and the stock bolts in the required locations.Needed fot the Alt brace and A/c brace.

was your car much loader after removing the precats??

If you're reasonably good at wrenching, replace the camshaft. You can get GOOD ones for well under $200. A camshaft is the BEST bang for your buck, and it only requires taking out a bunch more bolts. I would venture to guess you could change the camshaft in about 2 days time.

So I'm reading this post, and I'm curious about any effect that a different cam would have on the computer stuff. Does it work like a thermos? (you know, it knows wether to keep stuff hot or cold, all by itself!)

I'd like to put a different cam in and I've done it before. But I would rather not screw up a perfectly good running engine :stupid: if you know what I mean.

Exh mods are the best bang for $$ you can do on a L98.


Noramlly, I'm with you. This time... not. I think a cam will lower your ET an increase your trap more than exhaust. Exhaust is a SMARTER mod, IMO...but won't give you the ultimate gain that a cam can.

You don't NEED to reprogram w/a mild cam, but for optimal results, you would.

So I'm reading this post, and I'm curious about any effect that a different cam would have on the computer stuff. Does it work like a thermos? (you know, it knows wether to keep stuff hot or cold, all by itself!
Youre car is Mass Air (as you know) so it will "self adjust" somewhat. As I said above, optimum gains would be seen w/a dyno tune, but you can get 90% of the benefits w/10% of the money getting it "close enough" w/a AFPR and thoughtful tinkering. Feed it what it wants.

Normally, I'm with you. .

:cheers:
Problem as I see it there are few cams worth swapping in that will give much improvement with a stock TPI.

was your car much loader after removing the precats??

Well, hard to say. I removed the precats at the same time I put on the high flow mufflers. I will say this, it gives a nice little "I'm a V8 - F you Hondas" girgle at idle, nice deep rumble at street levels, and is almost deafning at WOT. I can't help but think some of that was thanks to the precats coming off.

Would be more than happy to post a sound clip sometime. :-)

Mike

Well, hard to say. I removed the precats at the same time I put on the high flow mufflers. I will say this, it gives a nice little "I'm a V8 - F you Hondas" girgle at idle, nice deep rumble at street levels, and is almost deafning at WOT. I can't help but think some of that was thanks to the precats coming off.

Would be more than happy to post a sound clip sometime. :-)

Mike

:burnout: :beerbang: this thread is useles without a sound clip. But I could imagine that it sounds good.

The problem I've seen with cams is at idle. If the cam has much overlap, it will ilde rough or unstable or not at all, without rertuning the ECM.
As long as you install the the O2 in the headers, you'll have no drivability issues. That's why I'd do the headers first.

True about the idle issue, but l love that nice lumpy idle my car has with a cam. nice power gain too. :burnout:

Relocate the the intake air temperature sensor to the air clearer duct. The heat load where it is located on a stock C4 gives the ECM (Electronic Control Module) a false reading and the ECM responds by cutting back on the fuel/air mixture to a leaner value than is actually required.

There is a reported 3-5 horsepower increase but there are no published dyno runs to back this up.

Another suggested change involves the air filter. The stock filter and air cleaner lid restrict air flow. Discard the stock filter and replace it with a K&N air filter At the same time, either open up the stock air cleaner lid with a pair of tin snips
The claimed horsepower increase is 3-5 for the filter and another 3-5 for the opened up air filter cover. The change is relatively inexpensive and very easy to do.

Another source of air flow restriction are the two screens in the Mass Air Flow Sensor on the 85-89 models. Just removing the screens will increase the airflow by approximately 125-150 CFM and that works out to around another 10 horsepower gain. (This was a common practice in the days of the Corvette Challenge races. Everyone did it).

This mod costs you nothing except your time. It is easily the cheapest, easiest way to get an increase in performance you can feel (NOTE: Make absolutely sure you clean the MAF device bore of all metal fragments from your screen removal activities but don't touch the wires on the inside of MAF sensor or you will ruin it).

While you have the MAF off, take some carb cleaner and a shop rag and clean out the throttle body bore of any residue. clean both sides of the butterfly. It will improve the idle.

Streetrunner Hypertech chip and replace your stock ECM PROM with it. The advertised increases are 15-20 HP and 20 ft/pounds of torque.

you can also spring for performance mufflers and obtain a 30-50 HP increase plus a torque increase you can feel.

Streetrunner Hypertech chip and replace your stock ECM PROM with it. The advertised increases are 15-20 HP and 20 ft/pounds of torque.

Or you could adjust your FP and timing yourself and save $$$ while accomplishing the same thing. A cam is cheaper than a chip anyway.

The problem I've seen with cams is at idle. If the cam has much overlap, it will ilde rough or unstable or not at all, without rertuning the ECM.
As long as you install the the O2 in the headers, you'll have no drivability issues. That's why I'd do the headers first.
Thanks a bunch, guys. This helps me formulate a plan. I'll keep you posted what and how things go. :sm_party:

Lee