AlphaLS1

98.3mm sleeved LS7 intake manifold pics.

alocker

iTrader: (10)

What are you going to use to seal the throttle body?

AlphaLS1

A thin film of RTV is all that's necessary. The seal is good enough it takes some effort to separate the throttle body from the manifold.

Troux

iTrader: (4)

Any room to hit the magic 100 number?

AlphaLS1

Yes, the manifold's flange/throat area has enough plastic that a thin wall tube with a 100mm ID will fit. I used a length of 4" exhaust tube with a 98.3mm ID because it was convenient. Also, the largest I could bore my NW 90mm throttlebody was just over 98mm so going to the trouble of sleeving the throat to a full 100mm wasn't worth it in my case.

one fast zo6

iTrader: (490)

NICE WORK!!!!!!!!

Haans249

iTrader: (24)

That right there is really cool. I sent a PM to ya.

ramairws6

iTrader: (33)

Cool! I was going to attempt this until I spoke to quite a few head and intake guru's that explained that even if I would open my intake up I wouldn't gain any horsepower over what I have now?

AlphaLS1

ramairws6, you have a classic restrictor plate combination. A big high rpm engine, an intake manifold with relatively large runners that match the large LS7 intake ports and a big throttlebody. Between the 100mm throttlebody and relatively large intake plenum you have a 92mm intake throat. Manifold pressure at high rpm WOT with that restriction removed has to be higher.

The head porters you talked to probably don't offer a solution to the 92mm throat so they may have simply been saying we don't offer it so you don't need it. Otherwise, they would be recommending a FAST 80mm intake with a large throttlebody as a sweet setup.

ramairws6

iTrader: (33)

Actually after my intake was ported and the throat cleaned up I am at or around 94-95ish mm opening. I do have a slight ridge or lip by the o-ring that I don't care for. I know it's not helping me any but don't have a clue if it's hurting me either!? I would also think that the true 100MM opening with my 100MM throttlebody would help but who knows??

98Z28CobraKiller

iTrader: (17)

Would love to see a back to back dyno of this before and after. I don't think that it will gain anything unless you are making over 1000rwhp. A 90mm throttle body can flow ALOT of air.

Haans249

iTrader: (24)

He will certainly gain. It may not be 15rwhp, but certainly something. I've seen before and after results, just can't remember where. Gained 6 rwhp, and about 5 rwtrq. So, every nickle and dime counts!

AlphaLS1

The trend is to go larger and larger. The post in the Dyno Section shows a gain going from a 90mm to 95mm throttlebody without increasing the throat size. Also, FAST's pending LSX/R manifold will accommodate a 102mm throttlebody.

ramairws6

iTrader: (33)

Sure would like to have a back to back comparison. I'm figuring maybe a 3-5 horse increase but who knows??