I pretty much have a stock motor, just an EPS cam and some headers right now.

My car is pulling vacuum, so I know I have an intake restriction. I have a FAST 92mm throttle body sitting around, the question is which FAST intake should I get?

Prices for the FAST 92 or FAST 102 are the same. I know there are collateral things I need to buy to make the FAST 102 work, like fuel rails, injectors, etc.

Just based on performance, which is the better one to get? FAST 92/92 or FAST 102/92?

 

102/92 hands down.

 

when is your car pulling vacuum ?at idle or high rpms ?the fast 102 intake is worth maybe 4 more hp.I like the 102 intake but I will stick with my 92mm intake.they don't make the fast 92 mm intake any more,so you have to find 1 used.

 

Pulling the vacuum up top. I've found a FAST92, so I can buy it if I want. Just a question of whether the 102 out performs the 92 enough to warrant the extra work and money to install the 102...

 

I've a question, if it's dumb just ignore me..i'm confused how'd you pull vacuum with cam only motor with ls6 intake, while i have heads and cam, and my ls6 intake was fine (not pulling vacuum) at all..

 

Your cam isn't the same as mine. Your headers aren't the same as mine. Your motor isn't the same as mine. My chassis (Porsche 944) isn't the same as yours.

Beyond that, I have no idea...

 

I think Vengeance has a sale right now for $900 on PORTED 102's. Might help make your decision.

 

What kind of intake path is in front of the ls6 intake?

A Fast might not help as much as you would like if you aren't sure that is the restriction. Also how much vacuum are you pulling?

 

I'm using the K&N fpik filter, the silicone boot it came with, going into the stock MAF, then into a metal pipe, then into a ported stock throttle body. Completely straight path, whole intake is maybe a foot long...

Can't remember exactly how much vacuum, but it was obvious while logging on the dyno.

 

Go with the 102

 

Does the 102 out perform the 92 by a substantial margin? If it's just 5hp it's not worth the extra cash to get the 102 to me...

 

Well, if I were I'd go with 102 but it's me, I'd spend the extra $ for 102 instead of getting the 92 and always second guessing what would happen if you go with 102. Bigger is not always better BUT in this case, if you look hard enough, you'll see some posts from tony mamo saying the main difference between 92mm and 102 is not only on the plenum size but the runners design too.

Just my .02

 

Talked with my tuner and decided to go with the 92. He did say the 102 would perform better, but it sounded like it'd be a small incremental difference.

I flat out told him I'd get the 102 if it added 10+ over the 92, he told me to get the 92...

 

I want to bring this back just because I'm looking at the 92 vs 102. For a while I was set on the 102, but I've seen plenty of great results from the 92.

Has anyone actually tested the difference on an aggressive heads/cam car?

The money difference is not huge, but there is a difference. If there is essentially no HP difference, then spending any additional money seems like a waste to me. I say that, but I'd actually consider getting it ported/port matched if it was worth 10HP for example...

The only example I saw was from Vengeance ported 92/92 to ported 102/92 and I think it was like 9HP...

 

I also would like to know some more benefits of the 102 over the 92mm. I think I read that withthe fast 102mm you need to trim certain things to get the manifold to fit correctly??

EDIT

Thist thread seems to cleaer up alot.

https://ls1tech.com/forums/generatio...sx-yes-no.html

 

only place i can see a 102 over a 92 is anything other than a stock cube motor. i think even a healthy 383 would see 10+hp using a 102 over a 92.

 

Well if the runners are better in the 102 and can be more easily port matched to the heads, that might be worth something even on a healthy heads/cam car.

102/92 combo with the LS2 rails comes in about 200 more than the 92/92 combo. I'm not sold that the 102 TB is needed on a h/c car and that's where most of the install issues come from. However, if it's only worth 5hp, but can be made to stretch out to 10 or 15 with proper porting, then it might be worth it...

 

i have a 90/90 on my 408ci, i wanted to swap to a 102 but for as many people say you will see gains theres just as many saying you wont sooo idk

 

I was talking to my tuner about the 102 vs 92 and he said on average he sees a 5hp difference between them.

 

Yeah... I don't think I'd switch from a 90 to a 102. Not worth it. But coming from an LS6 if one is worth 15 and the other 25 then that's an easy choice for a mod that's already struggling in the $ to hp ratio.