[Justin00Stang]

Yesterday Kent brought his 08 GT500 over from Louisiana. The car already had a 2.6 upper pulley, JLT intake, and tune.

In the interest of saving time, we assumed a setup like that, with the weather conditions were were having, and stock exhaust, would make about 535-540RWHP and similar RWTQ.

I went ahead and swapped the Innovators West 10% OD Balancer on, I put one of my tunes in the car, and ran it so we would have a baseline before installing the ported blower. It made 559RWHP and 598RWTQ. Notice the very large disparity between HP and TQ, at this point you can see how choked the stock blower is. A lower usually picks up around 25-30RWHP and 50RWTQ over an upper pulley only on a stock blower/stock TB.

I then swapped on a ported blower that Brian at Posi Performance did for us last week, I just sent him a spare blower that I had so Kent would not have any down time. When I sent him the blower I also sent one of the new high-flow inlet elbows to him so it could be port matched to the blower.

http://vmptuning.com/GT500/proto/posiblowerinlet.jpg

http://vmptuning.com/GT500/proto/elbowandtb.jpg

A couple hours later we were up and running with the ported blower, high flow elbow, and 67mm throttle body. After dialing in the tune, the car made 608RWHP and 609RWTQ, the stock blower was no longer choked off at higher RPM and once again making a square HP and TQ number!

http://vmptuning.com/dynographs/kentportedgt500.jpg

I was pretty happy with the results considering the car had stock manifolds, cats, and mufflers. From experience I know this car has more exhaust back pressure than intake boost pressure, due to the factory cats. This car would drop about 1psi on the manifold boost readings with stock cats removed, as they are very high right now for a stock blower with upper and lower. It would easily pick up another 10-20rwhp with better cats, and possibly a little more with LTs, I'm trying to convince Kent to do that next . These types of numbers from a stock blower start to rival an out of the box TVS setup.

[Dave]

Sound like some fun and some good numbers. I'm really wondering what a set of LT's would do with all the mod's. Seems like everyone wants to throw a set on with a more or less stock motor and expecting great results. I just have not seen a good dollar return for the gains.
Dave

[Justin00Stang]

Originally Posted by Dave

Sound like some fun and some good numbers. I'm really wondering what a set of LT's would do with all the mod's. Seems like everyone wants to throw a set on with a more or less stock motor and expecting great results. I just have not seen a good dollar return for the gains.
Dave

I think there is 20-30rwhp at this level. They are very expensive for the gains you get, and the gains are not as good as the exhaust companies advertise, but I guess a lot of people do them when there is not much left to put on.