My car is going to be set up the exact same way as the turbo car Speed inc posted numbers on a week or 2 ago. 348ci w/ GT76R turbo, stage2 heads 225/225 .581/.581 113lsa cam, LSX 78 mm intake and 78tb, etc etc. The other car made 675rwhp @10psi on 93oct and 844rwhp@16-18psi on 110 or 116oct. i think. My question is do you think would i see any noticable gains moving up to the LSX90mm intake & 90mm TB? Thanks for any input and suggestions.

 

Anyone with an opinion? PSJ maybe

 

I think there would be a gain, thats a givin, worthwhile? Yes in my opinion. Do you really need 20rwhp when your at 800+? Might not be worth the money then.

 

I have a 80mm bbk on a 78mm fast opened up to 80mm. I really dont think I would se much at all on my car. maybe 5-10 rwhp? But im just guessing.

 

true but not much of a gain, guess thats why tom didnt reccommend it but every little bit helps. Mostly i thought id see more of a benefit with higher boost levels(who knows) plus i could use the 78mm on my trans am. thanks for chiming in guys

 

I think you get same HP at lower boost level...so I think that can be considered an "upgrade". I would like to state I have a friend that makes over 1250 rwhp through a 78 mm tb/manifold w/ twins though...so in the end I dont think its very limiting.

 

FWIW, I tested an LS1 vs LS6 vs LSX on my single turbo Formula earlier this year. Even at the 700+rwhp, there was virtually no difference at all between ANY of them. Though I did not try a 78mm vs 90mm TB, I did compare a stock TB to a ported TB and also saw no gain. Definitely not worth the money for the LSX and 90mm TB in my opinion.

Hope that helps,

 

Rob that is great info. Thanks for the sharing.

 

K, think im confinced that im not getting the 90mm setup. Thanks alot for all your input guys. Thank u to Rob for adding in as well.

 

I also remember reading that the LSX manis where only tested up to 10 psi. Someone here got a full refund from LSX because he was trying to run 14psi and the manifold wouldn't take it (with out plastic welding or some kind of sealing work or something...)

 

I herd somethin about the glue not holding to well too. hhhmmm. I would stick with the same TB and intake and spend some money on suspension, gonna need it with that kind of power.

 

I'd save your money and invest in tires, you'll need em.

 

I got the tires and most suspension stuff. I really need some good seats though( still have factory ones)

 

Mine held 20psi.......... maybe more this week

 

Is urs a speed inc evil?

 

niiiiiiiiice

 

I would agree with this assesment, based on what I saw after it was installed on my car. The LS6 is still the best out there and really hard to beat for the money.

 

Im positive im stickin w/ the 78mm setup now. Thanks for the info guys. You just saved me some cash.

 

I was able to push in excess of 20lbs and no leaks through my LSX 90... Even the map stayed in somehow.

For the record Ive now switched to LS2 (for appearance).

Rob, thanks for the info...!

 

One of our local TT guys put the LS2 intake manifold and TB on his C5 and did see a noticeable power gain. Note that the power gain over the LS6 intake manifold wasn't until after 6000 RPM. This wouldn't help me as I run a stock cam and a stock bottom-end (meaning I shift around 6000 as the boost is still growing and my cam really isn't making much above 6000 anyway) Is it worth spending $700-900 for the swap on a FI car? Not in my opinion. If you want more power turn up the boost..

Cheers,

Mark