Downpipe feedback??

[griz_83ho]

Looking for feedback on a downpipe I was looking at possible buying. It's off of a fellow member so not trying to offend anyone at all, just looking for the pros and cons. Looks really nice and still new but wondering if anyone can give feedback on this downpipe. Were you able to control boost accurately? It's going on a pump gas motor with a TE45a turbo and percision front mount, and looking to keep boost below 20.

Thanks, kris

 

[coach]

First off...which pipe?
Second...pipe does not control boost, the waste gate/boost controller does.
Third...a 45a loves boost. It's not big enough that it will make big power in the teens...it likes 24-28 or more.

Edit.....I just saw your other post. That's a GN1 pipe. To be honest...it's a roll of the dice. I had one. Worked great with my little 49. Moved up to a 62 and could never keep boost consistent. There are many posts about these pipes. Do a search. They do fit great.

 

[bison]

Coach, what do you mean it's not big enough to make power in the teens? I'm confused by that statement and it contradicts what I've seen during dyno testing. With really good heads, CR on the 9.1-9.3:1 range and no other bottle necks I've seen 540-550whp at 18-19psi with non aggressive timing on 93/alky. If you look at the map and assume 2.25:1 PR at 18psi with almost zero inlet restriction at sea level(14.7+18)/14.5 you're sitting right on the edge of the 74% island @58-60lbs/min. It doesn't get much better than that. Most v6 engines on here won't flow that much mass flow at that low pressure ratio that's where the bottle neck is. It's the engine. Not the turbo. The above was with a Buick 3 bolt and clipped (less than 15 degrees) P trim ex wheel which probably choke flowed the combo a tiny bit compared to what a t4 .81 would achieve. I didn't get backpressure data but it couldn't be much at all to hit those numbers. Fwiw similar stuff at 14psi with the same turbo on it made 430 whp. So it's pretty happy in that 2-2.25:1 PR range if the engine can swallow what it can deliver.

 

[coach]

Always heard it had a "sweet spot" in the mid to high 20's.
When I asked the same question a few years back...I was told that. Your the man on turbos and you have numbers.

 

[bison]

Always heard it had a "sweet spot" in the mid to high 20's.
When I asked the same question a few years back...I was told that. Your the man on turbos and you have numbers.

Even at high pressure ratios it kicks ass between 55 and 60lbs/min that's why it's been so popular on these engines

 

[blackgn1]

My GN1 pipe didn't work properly. Couldn't control the boost. It's still new in the box. In storage.