Need help on 1991 L98 modifications
Racer
Joined: Feb 2018
Posts: 389
Likes: 77
Doh! I got caught up in his question. Still, from what I see, Innovate makes the "chip" which is some sort of thing you splice into the MAF to change the readings. Guess he will have a hard time doing that. Must be why they don't post instructions on the site if it is THIS. Oh well, I was going to use it myself. Nothing I like better than cheap and easy performance and eating flying pigs.
Team Owner
Joined: Jul 2004
Posts: 28,432
Likes: 3,285
From: Hartford WI
Kinda why I think it screws with the MAF values to fool the ECM into dumping more fuel. They know that it is cheap and the buyers don't know better and want something good for cheap.
Max G’s
Joined: Nov 2008
Posts: 2,751
Likes: 78
From: Monroe OH
NCM Sinkhole Donor
Most of the mods mentioned are good but one I didn't hear mentioned was the March Underdrive 3 piece pulley set for the 91 C4. This kit definitely decreased parasitic loss from accessories. This is a worthwhile mod that can stay with you even with larger displacement engines. As mentioned before Id start with the exhaust then on to the engine bolt ons. The frisbee mentioned is a large disc bolted to your water pump pulley. It was placed on the engine to dampen the engagement of A/C but no noticeable difference when removed. Good Luck 
Team Owner
Joined: Jul 2004
Posts: 28,432
Likes: 3,285
From: Hartford WI
Most of the mods mentioned are good but one I didn't hear mentioned was the March Underdrive 3 piece pulley set for the 91 C4. This kit definitely decreased parasitic loss from accessories. This is a worthwhile mod that can stay with you even with larger displacement engines. As mentioned before Id start with the exhaust then on to the engine bolt ons. The frisbee mentioned is a large disc bolted to your water pump pulley. It was placed on the engine to dampen the engagement of A/C but no noticeable difference when removed. Good Luck
Max G’s
Joined: Nov 2008
Posts: 2,751
Likes: 78
From: Monroe OH
NCM Sinkhole Donor
Team Owner
Joined: Jul 2004
Posts: 28,432
Likes: 3,285
From: Hartford WI
It turns the alternator and water pump slower so I do question whether the gain is worth the cost. The frisbee, well, that helps but you gain a little roughness, I'm sure. The water pump and alternator, one is cooling and the other is charging. Kinda more important. Not sure if the gains are worth it. Obviously, if you spin the motor to 10000, sure. At idle to mid, is there much of a loss in both alternator and water pump? Assuming there is something in the equation that helps power other than a feeling.
Melting Slicks
Joined: Nov 2013
Posts: 3,451
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From: Greater Cincinnati Area.
Max G’s
Joined: Nov 2008
Posts: 2,751
Likes: 78
From: Monroe OH
NCM Sinkhole Donor
It turns the alternator and water pump slower so I do question whether the gain is worth the cost. The frisbee, well, that helps but you gain a little roughness, I'm sure. The water pump and alternator, one is cooling and the other is charging. Kinda more important. Not sure if the gains are worth it. Obviously, if you spin the motor to 10000, sure. At idle to mid, is there much of a loss in both alternator and water pump? Assuming there is something in the equation that helps power other than a feeling.
And to take it a step further; the water pump and alternator do take an X amount of power to turn. That’s why electric water pumps are used by some in drag race application and even track application. There are some guys that don’t even run alternators when drag racing. There will, if not already be vehicles without alternators and belt driven water pumps in order to reduce parasitic loss and get better efficiency from the engines.
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Team Owner
Joined: Oct 2004
Posts: 81,241
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From: altered state
St. Jude Donor '05
If all you want is low 14s use some headers and a larger converter that should do it .2000 is so tight it feels stock
3.07 gear and a 26-2800 felt great.
A 3.45 gear would feel night and day, not too little not too much
Those 2.xx gears are horrible
3.07 gear and a 26-2800 felt great.
A 3.45 gear would feel night and day, not too little not too much
Those 2.xx gears are horrible
Team Owner
Joined: Jul 2004
Posts: 28,432
Likes: 3,285
From: Hartford WI
Well I can say I’ve had 10yrs of testing the under Drive pulleys in Racing application. AutoX and time attack. With a sbc 350 and sbc 406. No cooling issues or charging issues. And I do run a lightweight Battery with no issues charging. RPMs usually range between 2000 and 5000rpm with idleing in grid. And a faster increase in rpm is relative to faster acceleration.
And to take it a step further; the water pump and alternator do take an X amount of power to turn. That’s why electric water pumps are used by some in drag race application and even track application. There are some guys that don’t even run alternators when drag racing. There will, if not already be vehicles without alternators and belt driven water pumps in order to reduce parasitic loss and get better efficiency from the engines.
And to take it a step further; the water pump and alternator do take an X amount of power to turn. That’s why electric water pumps are used by some in drag race application and even track application. There are some guys that don’t even run alternators when drag racing. There will, if not already be vehicles without alternators and belt driven water pumps in order to reduce parasitic loss and get better efficiency from the engines.
In the future, who can say. I agree that the less you have to run with in a competition of speed, the better. More weight means more power to achieve the same results. What I am not sure about is that barring a race situation, is it really beneficial on the street?
Team Owner
Joined: Jul 2004
Posts: 28,432
Likes: 3,285
From: Hartford WI
I really wouldn't. If I were changing the TC, why put a new TC in front of an older trans? I'd wait till rebuild time to do the TC which should be matched to the cam's needs. As to the rear end, why spend any money on an old D36? Wait till you get the D44 to spend the money.
Safety Car
Joined: Jan 2014
Posts: 4,017
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From: Poughkeepsie New York
Originally Posted by aklim
As to the rear end, why spend any money on an old D36? Wait till you get the D44 to spend the money.
Team Owner
Joined: Jul 2004
Posts: 28,432
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From: Hartford WI
Safety Car
Joined: Jan 2014
Posts: 4,017
Likes: 492
From: Poughkeepsie New York
Originally Posted by aklim
I suppose that for $200, if it holds for a couple of years, it's probably a good deal.
Team Owner
Joined: Jul 2004
Posts: 28,432
Likes: 3,285
From: Hartford WI
Can't remember who it was but I bought a D44 on the forum too. Most abuse it had was the dust particles hitting it while it was sitting. Sent it out for a rebuild and was told it was cracked and junk. Bought a lot of used parts myself and found it was much easier for me to be pleasantly surprised than to expect it is good and be disappointed.