Well, I just got back from the dyno and the news is not good--my S2000 lost 50rwhp with the T1R 70R Sparrow exhaust (as compared to the T1R 70RT). I am very frustrated right now. Part of the reason it lost some much power was because the car was losing 2-3 psi up top. The tuner attritubuted this to the restrictive exhaust as it wasn't losing any boost with the 70RT.

So, I am going to put this 70R Sparrow up for sale and have a custom dual exhaust made. We are looking at doing a 3.5" main pipe branching off into two 3" dual pipes with HKS mufflers. Then it will be back to the dyno!

 

I don't really see how you could be losing so much hp to an exhaust as long as you run a 3 inch testpipe. I ran with stock exhaust at 408 whp and 270 torque at 9 psi. I then decided to change to a custom 3 inch mendrel bent dual exhaust. I only made about 20 wtorque and about 400 rpm quicker spool. The discrepancy shouldn't be that much w/ or w/o aftermarket exhaust as long as you are using a 3 inch tp.

 

[QUOTE=koji187,Jan 20 2007, 03:20 PM] I don't really see how you could be losing so much hp to an exhaust as long as you run a 3 inch testpipe.

 

Before I go and have a custom exhaust made, I am going to have the car put back on the dyno with the current exhaust disconnected. If the power comes back and the boost does not fall off then the problem will have been successfully identified.

 

good idea going with the custom weld, that what i did and im very happy with it, I have 3in all the way back to an invidia y

 

WOW!! 50rwhp just from an exhaust....hum...that doesn't sound right.

 

I believe it, since my car would only boost to 6psi when I had my HKS dual exhaust on the car. After I switched over to a 3" single I was boosting closer to a full psi more. Do you think that this has anything to do with your new wastegate dump? Just an idea since the 70mm dual doesn't seem that much more restrictive to limit boost so much.

 

I asked the tuner that, and was told that having the dumptube venting to the downpipe wouldn't cause the boost to fall off.

The 70R has a 70mm main pipe with 63mm duals. I think the 63mm duals are the problem.

 

This is pure BS.



You my friend need to find a new tuner.

I have the T1R Sparrow 70mm and made 400rwhp @ 14psi with the 3mm head gasket. There is not a chance on this earth that I could go to a 70mm or 3" single and gain 50whp.

It couldn't possibly be the dump tube into the downpipe mod - right.

 

If you still have your stock dump tube try putting that back on. If I recall correctly you never re-dyno'd with just your dump tube mod right? You modded the dump tube and switched exhausts. Correct me if I'm wrong.