I hope to get the truck on the dyno after the new LS2 90mm TB install.....(attention Crash Dummy ;) )

last time on the dyno was 450/439, backed up on another dyno in my town with a 444/448 pull. We have seen some substantial gains with the 90mm on the engine dyno (up in the 40 or so hp), the Radix really responds to the Bigger TB. I hope to pull in the neighborhood of 465-470 rwhp after the install and a little tune to keep things safe with the new air flow....We shall soon see!! I think at that point I may have reached the limits of the stock exhaust manifolds and might have to step up to some headers.....I know everyone likes the Pacesetters, any more thoughts on headers?

I really think the larger TB is the way to go with the radix. I think it is restricting mine terriably. Can't wait to see the #'s!
Pacesetters....Love em. Mine are 4 months old and still look brand new.

I really think the larger TB is the way to go with the radix. I think it is restricting mine terriably. Can't wait to see the #'s!
Pacesetters....Love em. Mine are 4 months old and still look brand new.


I keep bouncing back to Shorties......I know I know.....not as big of a gain, but if I go with the 1 5/8 JBA headers coupled with the MagnaFlow high flow cat system it might be good to go, and Cali legal.

and yes, at the level of boost you are running a larger TB would be the way to go for you.

For you non DBW guys, this has to be the BEST 90mm TB on the market today http://www.umiracing.com/ (click on LS2 TB) Pretty sure it has a 4 bolt flange, so some fab work may be needed. They have intoduced the Parabolic throttle bore that can be found on all LS2 90 mm TBs. THis pretty much eliminates the part throttle tuning issues. This is the TB we did the development testing with on our engine dyno....

http://www.umiracing.com/gallery/Images/Blk%2090mm%202.JPG

thats sweet...cant wait for the results....

thats sweet...cant wait for the results....


Hope to have some this week.....

Remove the airfilter,my K&N collapsed while the truck was on the dyno.It will respond well with the 90mm throttlebody.The shorties might help if you found some with 1 3/4" tubes.Have you considered a set of TOG headers,big tubes with a mid length?

I have the TOG headers and they are top notch quality. I have had them for a year, no leaks. They are titanium ceramic coated and the coating still looks fine. A bit pricey though.

Currently, they are flowing into my stock cats and y pipe. One side, the cat goes almost directly into flange of the header. I will have some new high flow cats, x pipe, true 2.5" duals in the next few weeks and that is when I will probably really see the benefit of the headers. Im hoping for around 30 rwhp or so.

I've been told that on a 5.3, we'd be better using the TOG's, or Bassani mid length headers because they're 1 5/8 tubes instead of the 1 3/4 tube long tubes. Better low end torque. Do you have a part # on the Magnaflow y pipe?

i certainly do agree with you on this one. one of the other trucks running a magnacharger from a magazine stepped up to a BBK throttle body on a recomendation for a bigger throttle body. since the radix is on the manifold side of the throttle body the restriction shows up considerably more than if you were running a centrifugal and boosting past the throttle body. my guess would be around 20-25hp with an increase in torque to go with it.

I've been told that on a 5.3, we'd be better using the TOG's, or Bassani mid length headers because they're 1 5/8 tubes instead of the 1 3/4 tube long tubes. Better low end torque. Do you have a part # on the Magnaflow y pipe?
Part number is #15477.

If you decide to go with the Pacesetter's we have two new sets laying around here.

If you decide to go with the Pacesetter's we have two new sets laying around here.


Hmmmm, call me.

I cannt wait to see the results of this mod!!!!

If you decide to go with the Pacesetter's we have two new sets laying around here.
Call Blown Chevy and PM me about the other set please.

Thought you were sponsored by DYnatech:confused:

But yeah mjhowards headers looks really nice still and you cant beat them for the price.

If you could do the headers after the TB, it would be nice to see individual gains.

Aren't the TOG's legal in Ca?
What about ASM's?

Blown, is the LS2 TB compatible with the DBW on your 04? What all does it take to make the swap? Thanks.