98.3mm sleeved LS7 intake pics
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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.
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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? 
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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.
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.
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??
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.
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!
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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.
