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gear_monkey 01-25-2013 09:49 AM

Perrin vs Invidia Down Pipe question
hey guys. I initially posted this in the tuning forum but I think it belongs here.

I have an 05 GT. Had an STI up and Perrin catless dp put on plus a dyno and street tune.
The torque/power was amazing..lets say a "10" vs stock.
The problem was I have a 5EAT but the dp was made for a manual tranny. The dp rubbed on the firewall and against the tranny pan causing ALOT of noise and vibration in the cabin.
Today I dumped the Perrin and had my tuner put a beautiful fitting new invidia dp on.
All vibration and noise is gone but so is some of my torque. Now I would rate it at "8".
I'm assuming the loss of torque is because the invidia dp has a much sharper bend coming out of the turbo vs. the Perrin and this is resulting in a lower amount of air flow?
Do you guys think a street tune would bring back some of the lost power?
I love the new smooth quiet ride but man...I want that lost torque back!!

bigjweb 01-25-2013 09:56 AM

It's all in your head

Mr. Sinister 01-25-2013 01:19 PM

^ Yup.

gear_monkey 01-25-2013 01:22 PM

That's what I kept telling myself yesterday on the way home from the tuner. Having driven it to and from work today I can say without a doubt that some power was lost.

How and why I don't know.

robitrice 01-25-2013 01:46 PM

you are just getting used to it, so not it doesnt feel as obvious

gear_monkey 01-25-2013 07:29 PM

I found the problem!!!!

I resigned myself to being crazy and just having to "get used to it".

I was bored this afternoon so I jacked the car up just to get a good view of the downpipe.

After sliding under the car I immediately noticed that two of the bottom bolts on the downpipe were missing their nuts .... Yeah yeah

Anyway, I called my tuner, complained like a crazy man, then put new nuts on...yeah yeah, torqued them down and took a test drive.

BOOOM, all the power is back! Crazy to think if you put one of these on correctly they work.

Wow, I am thrilled...and I wasn't crazy..

robitrice 01-29-2013 09:00 AM

so u had an exhaust leak at the DP/CBE connection?

gear_monkey 01-30-2013 07:08 AM


Originally Posted by robitrice (Post 4267853)
so u had an exhaust leak at the DP/CBE connection?

Yep. The installer left 3 of the 5 bolts loose. Once I torqued them down all the power came back.

robitrice 01-30-2013 02:44 PM

there are only two bolts that connect the mid pipe to the DP.....there are 5 at the turbo/dp connection, interesting

gear_monkey 01-30-2013 02:53 PM

Yep. The two bolts at the mid were fine. It was the bottom three of the connection at the turbo.

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