nafornow

My car is a 97 corvette coupe, 6 speed w/ stock 3.42s.

Has:
-ls3 swap (from a camaro)
-227/239 .614 .624 115 +3 VR (stage 2) cam
-ported stock heads
-FAST 102
-ported ls2 tb
-vararam elbow w/ a big haltech filter
-doug rippie 1.75" long tubes
-unknown x pipe
-b&b bullets
-powerbond 25% crank pulley
-stock 42lb injectors on fast rails, and a racetronix fuel pump.

Here's what Im trying to decide. Right now I have ported 821 heads, fast 102 manifold, down to a ported ls2 tb, down to the stock 1997 75mm maf. It essentialy bottlenecks down.

The bought the car with these mods done already...except the fuel pump, rails, intake elbow and filter, and cat back (had borla stingers). I want to have it re-tuned, and figure itd be a good time to change the restrictive 75mm maf. I already have a brand new 85mm truck maf to install....but Im considering going with a card style, in a 90mm or 100mm housing.

I talked to the person at a very reputable local tuning shop, and he recommends NOT switching to the card style and bigger housing. He says it'll be a waste of money, ...and that they have 9 second cars running 75mm maf's.

Others have told me that I'd be holding back 10-15hp, by NOT going switching to the larger maf and housing. That 5mm less, is supposedly a restriction. The cost of the newer card style and 90mm housing, is not a concern. I mean hell....I just spent $400 on FAST fuel rails and fuels lines, cause I thought they looked perty.

It'd be neat to be able to say my car makes 500rwhp on pump...and if there might be a 10-15hp difference on the top end, seems like it'd be worth it.

Opinions from any experienced tuners?

Slowhawk

iTrader: (12)

I personally do not like LS3 type of sensors on the older PCM cars.A newer 85mm works good.

litle88

iTrader: (20)

Or just go SD!!
Quicker Throttle response. I love mine!

I'd run from that shop if they told you to keep that mafs, but I'd go with an 85mm if you can't live without one.

nafornow

jeez....I just realized I posted this in the wrong section.

This is my problem. If I ask two people...I get two different answers. Can either one of you, explain why?

Tainted

iTrader: (9)

Youre asking a question that is a 50/50 between maf and sd

Personally, for less than $100 you can make a 100mm maf with gm parts and thats my plan. Sd is great if you have the money or skills to tune it and dial it in just right.

Scoggin Dickey

iTrader: (34)

SD has it's place. MAF is superior for a street car in most circumstances. The problem with your car is that you have the old style 97-98 PCM and the operating system doesn't have all of the tables and parameters of the newer PCMs, therefore going to the LS3 isn't quite as doable. Hence Slowhawk's recommendation to run the 5 wire 85mm MAF instead.

I do like the 85mm over the 78mm and normally the card style over both, but in your application I'd run the 85mm MAF.

nafornow

Thanks for the advice. I guess Ill stick with the 85mm one.

With the head porting, 102mm fast manifold, and the ported ls2 tb....I hope the 85mm maf isnt holding everything else back.

Im considering driving it 575 miles, to bring it to Vengeance racing. Thing is, if something happens, man Id be screwed. I COULD trailer it there, but that would be an expensive trip. $500 in fuel (f250 pulling a trailer), plus the hotel and whatnot. I just dont know.