3" Down Pipe Limit

[87we410877]

What are my limitations with a 3" Down pipe? Considering it will be open downpipe. I have gone 10.6 @ 132. I am building a new set up. E-85 stage motor. I am looking to make around 800 RWHP at around 30 lbs. I think i'll be ok. Daily driven it will be de tuned to around 23-25 lbs. I think i'll be ok but just want to put some feelers out there and see what kind of #'s yall are making on a 3" DP.

Thanks!

 

[longball]

I've been wondering that myself lately........

 

[FASTV6HENRY]

low 9s high 8s no problem,

 

[Grumpy]

we ran high 9s @ 138 in a 3660# GN. Street trim and Alky.

 

[TURBOPOWERED68]

Ohh shit wrong forum

 

[87we410877]

Yea im thinking i'll be fine. Not too concerned with 1/4 mile times since the car will never be down the track. More of a HP Thing. Ported champion heads and intake with a 70mm precision BB billet wheel turbo. 70mm TB may have to be increased to 90 but i have some math to do there. I should probably just roll this thing off of the closest pier.....

 

[coach]

I'm sure Bison can go into a bit more depth, but the 3 tapered off in the 650-700rwhp range...depending on which dyno. Still works, but the 3.5 picked up in that area. Before building my new engine....this was researched very well. I only asked guys who had cars in the mid/high 9's and got this impression. It's not so much the pipe diameter, most said it was the sweep of the larger pipe off the turbo.
Hope this helps.


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[87we410877]

So my next question is who sells a 3.5" or 4" DP that fits with the heater box? Or am i going to have to make another one?

 

[Red C5]

Not to go off subject but a 70mm turbo will make 800 rwhp on our cars?

 

[Rafs-T-Type]

Not to go off subject but a 70mm turbo will make 800 rwhp on our cars?

Well a 6265 put down 696 - http://www.turbobuick.com/forums/threads/how-much-power-with-a-6265.368576/page-3

 

[coach]

Not to go off subject but a 70mm turbo will make 800 rwhp on our cars?

Yes it will...BUT different dyno's seem to give different ratings. Some are more forgiving and others are stingy.
The problem I have with some dyno numbers are the fact that our 109 blocks won't hold up to that kind of power. My builder told me repeatedly that the block is the weak point. 850-900 at the crank is pretty stout for a 109 build. I've been at the dyno sessions that Brian Lorenz runs during Norwalk Buick Racedays. I've seen a few really high dollar DLS engines make close to 700 at the wheels and Cal was tuning them. These are no expense spared kinds of builds. 28-30lbs out of a billet 71HPQ turbo. These are 109 builds with Champion GN1R heads fully done.
There may be members who can tell their experiences of bigger HP, but this is my example


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[bison]

Not to go off subject but a 70mm turbo will make 800 rwhp on our cars?

It will support that much if the back pressure is kept in check. It won't make power though. It only feeds what the engine can swallow


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[steve hughes]

My TSM combo 9.45 @ 144.00 mph with 3 inch open down pipe. 9.40 @ 144.50 with 3.5 inch open down pipe. Back to back runs at the track same day. All with 62mm TB.