Before all you guy's freak out about this being a boost thread here, it's an ITR, and this forum is the only one i trust with opinion's from my experiance's. So any help would be great...

I was just wondering if there was any big differance with the HP gain's on a Top Mount vs. Ram Horn? I've seen gain's on the ram horn, but only on a stock GSR with 10 psi. and those #'s where around 50-75whp. Havn't seen any on a Top Mount though.

I'm guessing there would be more HP gain's from the Top Mount because of the longer runner, but I've heard they spool smaller turbo's a little slower then a Ram Horn. I'm Just wondering because I'm running a T3/T67 and I love the spool but I really want to go equal length Mani. If at all possible, where in the Powerband would these gains be?

Anyone have any experiance with this? Or any dyno #'s? I've have a Stock Block @ 10 psi (B18C5) and a mildly built head (crower turbo cam's, port match, 3 angle, springs & retainers). I'm just wondering which would be better w/ 3'' DP..

Thanks for the help..

 

depends on what you want. if you want ac ramhorn is the way to go, although i think they make top mounts ac compatible now. 3" down pipe can go with either one, however you can use a 4" down pipe with the top mount. i wouldn't worry about more hp, because with the 67 you will have more than enough power to spin the wheels in all gears.

 

There is a thread where full-race compares both manifolds i just cant find it now.
Topmount will produce a little more but im a ***** and cant live without p/s

You have a big turbo for a stock engine, what exactly r your goals for the car?

 

Id figure out first how crazy you want to go with your car? Where will you be in a year?