Assume I know knowthing about the LT1 Intake manifold. Tell me everything about it.

Also, what alternatives are there in the aftermarket that are actually worth a damn?

 

It's a big, hollow tube. There are no aftermarket alternatives. You can port your TB holes for a larger TB, & you can port the intake runners.

 

http://www.hogansracingmanifolds.com/

Way overkill. They're people with 9 second cars that still use the stock manifold.

 

52mm throttle body could go up to 58mm...lol

 

out of curiousity... what do you think you would get, performance wise out of one of those $2600.00 manifolds, i think you would also have to upgrade your throttle body and heads too... am i right?(answer all of those Q's please)

 

They're all custom made so they probably have to have access to your car. Probably a 58mm would be ideal.

 

OK, kinda looking for detailed techical information here, not a link to someone who makes sheet-metal manifolds.

If nobody has any, that's OK, just say so.

 

I believe the runner length on the intake manifold is 3-inches, far shorter than most cars have, also much shorter than the old TPI or the new LS1/LS6. The short runners insure pretty darn good flow for higher rpms. I had mine cleaned up and port-matched to my heads and it flows plenty well. You can also go the extra step and have it extrude honed. Someone on here claimed a 25hp gain from extrude-honing a while back on here but that was on a 450hp motor, so you'd see next to nothing on a stocker. Also, the front of the manifold is only bored to except a 52mm throttle body or an Arizona Speed & Marine 54mm. If you want to go to 58mm or the 1,000cfm monoblade, you have to machine the manifold.
A while back Edelbrock prototyped a replacement performance manifold. They even went so far as to advertise them. The claim on them was 20hp over stock on a stock car and the asking price was $450. It never made it to production due to lack of demand.
TPIS has a miniram intended for TPI motors however, I've seen 2 of them modified to work on an LT1/LT4. I believe TPIS does the modifications themselves but only recommend it for stroker motors intended for VERY high hp #s.
Accel/Lingenfelter also made a replacement for TPI called the SuperRam. Up until 95 or 96 they sold modified versions of these for LT1s. Unfortunately, due to the fact that they had to reduce the height in order to fit it under the 4-gen windshield, the radius of the turn the runners made was not optimal anymore. They worked good for increasing low-end power and torque on stock, mild strokers, and supercharged cars but lacked any sort of top end flow. They're still a good piece and I believe ligenfelter still modifies them on a case by case basis. The price before mods is around $750.
One more alternative is an LT4 manifold. This is a very controversial issue. They have a slightly different runner length and are only intended to mate up to LT4 heads, but there are companies that modify them to fit LT1 heads. The problem here is The LT4 intake never fit the LT4 well and fits the LT1 even worse. People w/ modified and stock versions (people who did LT4 heads too) tend to have sealing problems both around the runners and at the front and back where the heads, block and manifold all meet.
Hope this satisfies your tech needs. Email me w/ any further questions. To the best of my knowledge, this info is all correct and up-to-date but anyone reading this feel free to correct me.

 

A stock throttle body inlet is 48 mm. The matching inlet on the intake manifold which it's attached to is about 52 mm. Therefore, you can safely buy a 52 mm one (like that from TPIS) and bolt it on in place of the stock one without any other modifications. Anything larger (like the 58 mm job from Lingenfelter) would require the intake manifold to be bored out to handle in the increased volume of air. The larger throttle bodies are not physically larger, they've just been bored out making the opennings larger.

 

A stock throttle body inlet is 48 mm. The matching inlet on the intake manifold which it's attached to is about 52 mm. Therefore, you can safely buy a 52 mm one (like that from TPIS) and bolt it on in place of the stock one without any other modifications. Anything larger (like the 58 mm job from Lingenfelter) would require the intake manifold to be bored out to handle in the increased volume of air. The larger throttle bodies are not physically larger, they've just been bored out making the opennings larger.

 

sorry, don't know why that came out twice...

 

LT1Brutus -

Those short runners...

Are they pretty much straight up and down? Tunnel Ram style?

 

I heard once that a longer runner increases torque. Is this true?

 

Has anyone seen any info on whether a ported LT1 intake is worth more hp than an LT4??

 

i've always heard that it is a waste of time to port the lt1 intake. supposedly the lt1 intake outflows the lt1 heads anyhow.