mark21742

I'm running an 04 A4 GTO with a fully built trans, 3,800 stall, milled, ported and polished 241s, 238/242 .595/.595 112 lsa Trickflow cam, lts and dual 3" exhaust.
The motor is setup to safely spin well over 7,000 rpms and the cam is rated for 3,000-7,000 rpms.
From what I've researched and read the ls6 intake (what I have stock right now) starts to choke out around 6,200 rpms and even the FAST ported 92 starts choking out over 6,500 rpms...

Is it time for me to move up to a sheet metal intake? Any insight on the different designs, pros and cons.
I have seen and love the twin 78mm tunnel ram design.

BlackScreaminMachine

iTrader: (17)

Is this a race ony set up?

Have you done anything to strengthen up the bottom end like rod bolts?

mark21742

As of right now its a track/weekend toy that I just happen to drive daily because I can and love driving it lol.
I have Katech rod bolts and Melling HV oilpump so the bottom end and oiling is good.

Also from what I've read with the sheetmetal intakes you lose bottom end... But like said I'm running a 3,800 stall so where do they actually lose power? If its down 20hp at 2,500 rpms I'll never know or feel it.

I've had my eye on the new AFR 215s but wait to see if they get the praise I think they will... This is all for a stock cube 346ci ls1

Tuner@Straightline

A FAST 92mm will be fine with your set up. My LS6 with a larger cam (244/248 .620/.622 @112+2), heads (TEA Stage II LS6), forged internal, Kooks 1 7/8" headers, and 11.8:1 CR spins to 7500rpm with no problem (peak power at 7200rpm, peak torque at 6100rpm), and I don't get intake restriction till about 6800rpm. You're cam should be peaking power wise around 6800rpm as well.

Unless you plan on spining past 7500rpm, sheet metals are going to be over kill. You can always go with a Victor Sr and 4150/4500 style throttle body and save some money over a Sheet Metal.

mark21742

Money is/isnt the issue, I would be the fabbing the intake if I went sheetmetal, even though I know it would probably take a few redesigns to get the best performance.

When you say overkill, do you mean just more than I need, or that it would hurt performance?

Tuner@Straightline

It wouldn't hurt peak performance but might effect low end torque, even with your 3800rpm converter, your cam doesn't start really pulling till about 4500rpm, so you'll still have 700rpm of powerband that the sheet metal intake really wouldn't be helping with. I mean overkill in the way that there would be very little benefit for the amount of effort in fab'ing a sheet metal intake over a FAST 92mm. They even have the FAST 102mm out there for cathredal port now.

Most of the sheet metal intakes are mated with engine/trans combo's where the torque converter has a 5500-7000rpm stall. For example:

zacht

iTrader: (18)

i think he's getting at overkill as its a pretty expensive setup for a h/c car. but on the other hand if you can build your own for half the cost of a fast, id say go for it.

also on the subject of losing power down low, this only comes from the short runner designs. if you can make a long runner design, similar to a fast or the LSX manifolds it would probably be great.

Ive seen a hogan intake that looked like a sheetmetal LS6 intake, looked awesome...just cant find anything on it. think it was for the TT Lingenfelter cars...dont know tho.

I've also contemplated trying to make some sort of long runner sheetmetal intake, designed like the LSx intakes. also make some sort of a mini-velocity stack into each runner (kind of like the fast intakes)

at the most, i say what do you have to lose? hours of your time and some aluminum?

fatmat80

i would say a sheetmetal is overkill as well. If i were you i would go with a ported fast 92 and maybe upgrade my heads to a set of ported 243s

Shawn @ VA Speed

iTrader: (3)

i will add this to the conversation-a poorly designed intake will hurt more than it helps.Proper runner length,runner taper,plenum volume and very important.I takes a long time and years of experience to get it right-really not for the do it yourselfer.

InsaneDomestics

iTrader: (28)

+1 For A Vic Jr/Super Vic With 4150 TB. They Are Made To Rev High RPMs. I Think You'd See A Decent Gain With This Setup... Just My Opinion

WS.6#384

iTrader: (6)

I wonder why this one is so cheap? But from what I have read people loose power not gain. Sure looks pretty though.

http://cgi.ebay.com/ebaymotors/LS1-L...Q5fAccessories