UPDATE: Problem Solved!!! So, check it out... After putting on the test pipe, I went back to the dyno in Vegas. Before even tuning, the car pulls 312 whp!!! REmember that's up from 291 with tune last week with the Cobb cat. After the tune, I'm at 331 whp / 334 tq on Mustang Dyno! Sweet. So after all that, it appears the Cobb cat was the main problem although switching to the Forge wastegate actuator was a nice move too. So, at the beginning of all this, I was at 258 whp on the dyno in Vegas with the mods and Cobb Tune. Three steps later (forge actuator, replace Cobb cat with Cobb test pipe, and re-tune) and I'm at 331 whp. That's 73 whp gained mostly due to a test pipe and tune. Oh, and the difference at redline is nearly 100 whp. Thanks to all for your advice and feedback. I'm feeling good today. Next step: Aquamist kit.

 

awesome! so the cobb cat was holding it back... im tempted to replace my br cat.

 

Don't mean to thread jack but I'm hoping someone on here can help me out.

a.) Same problem, 267 whp on mustang dyno. Seems kind-of strange for the mods I have right(see sig)??

AND

b.) I already have / did what was suggested/worked for you, but my numbers are still 267!

- Hallman pro MBC
- Absolutely no boost leak
- Replaced throttle body seals
- Perrin test pipe (no cats)

Tuner said that the turbo in the 05 evo just cant hold boost is that true?

Am I way off here in thinking that I should have a lot more power than 267 on mustang?

 

To be honest thats right about what I was making on that dyno with similiar mods. I think I was at 272hp...go to the track. You should still see good results.

 

Not true... I have an Evo 8 turbo and I have no problems making 25psi and holding it well into 7000rpm. I made 330hp on a mustang dyno with similar mods on 93 octane just a couple months ago.

 

So I'm not crazy for thinking that 267whp on mustang dyno is incredibly low?

Man 330 whp on mustang is what I was hoping for. I told myself that I just had too high of expectations, but it's starting to look like I had realistic expectations and something is just wrong. I'm totally bummed and don't know what to do.. Any suggestions?

The tuner just said that my car simply couldn't hold the boost and to get a 9 turbo. It feels like I'm throwing a band-aid on a bigger problem. I wonder what that bigger problem is...

 

On a properly calibrated Mustang dyno on 91 octane, 330whp is not something you're going to hit unless you have an Evo 9 turbo and a lot of other mods. And even then, 330whp is not always possible.

 

FWIW, I also had low numbers on a Mustang dyno, and after putting a new factory WGA it was fixed. I have autox rules to worry about so you dont need to buy a factory one, but its definitely something to consider.

 

Thanks for the words of advice, about how much was gained purely from the new WGA? So you think if I just run a different turbo with new WGA the problem will be solved?

 

There is no problem with your car, those numbers are about accurate on a Mustang Dyno for an Evo 8 turbo. My advice to you is to either get a Stock 9 turbo or an FP Green or BBK Full with supporting mods etc. Don't try to reinvent the wheel its all been done before , there are plenty of setups with the number you are looking for in the dyno section