dbb 6776 vs dbb billet 6765
- Thread starter stk6bngr
- Start date
With the PTC 9.5 non lock up you have I would be curious.
This would probably work with the billet 67 dbb turbo. The journal bearing would probably be a bit lazy for my liking.
- Joined
- May 26, 2001
http://www.turbobuick.com/forums/tu...recision-turbos-new-turbo-listing-buicks.html
6776 with H cover is rated at 780.
Billet 6765 with H cover is rated at 875.
Hope this helps.
Patrick
With the PTC 9.5 non lock up you have I would be curious.
This would probably work with the billet 67 dbb turbo. The journal bearing would probably be a bit lazy for my liking.
maybe i should just get it and see how well it spools with a 2800 stall
I agreeWith the PTC 9.5 non lock up you have I would be curious.
This would probably work with the billet 67 dbb turbo. The journal bearing would probably be a bit lazy for my liking.
so your saying theres hope that i might be able to get away with a 2800 stall on a 6765 billet dbb??? heheh
GNBRETT
Pelennor Fields
- Joined
- Feb 8, 2004
I had the 6776 DBB with a ptc 9.5 2800 and switched to a 6765 DBB. I asked dusty branford about the stall and he stated that it should work fine.
I upgraded to a different motor/heads so i will have to loosen mine up but from what i was told it would work with what I had which was a 206/210 roller with champion iron heads
I upgraded to a different motor/heads so i will have to loosen mine up but from what i was told it would work with what I had which was a 206/210 roller with champion iron heads
PTC doesnt rate their 9.5" converters by stall speed. They are spec'd by the stator/pump combo. If you had a problem spooling with your PTC 9.5" you could send it back for an optimal setup. If your spending as much as it costs for a Precision ball bearing pulling a converter and sending it for an adjustment should be a minor inconvenience even though youshould have no problem. Imo most guys who order ball bearing and keep trying to use their dinosaur converter are just better off ordering a journal turbo (or keeping their current turbo) and a PTC 9.5". Almost the same cost and they can sell the dinosaur a recover a few hundred $. The converter will net more gain than the turbo will almost everytime. Ive got an old t-netics 66 ball bearing on my car that went 114mph in the eighth and 137mph in the quarter last night as i lost a cylinder at about 1000ft due to an error on my part on a previous run. If i had picked up 27-28 on top like like i normally do i would have gone 141-142mph. Charge air temp at 6000 rpm at 137+mph was 72. Ambient temp was 59. A 13 degree increase. I doubt theres much for me to gain with a different compressor. So at 700+hp with an old cast compressor im making way more power than most on here ever will. The 9.5" PTC converter is the only thing that allows me to keep rpm down enough to be able to run a hydraulic valvetrain setup like i have. The drivability difference between the 9.5" PTC converters needed to spool a journal vs. ball bearing is almost nothing if you are running a 3 bolt and under 650hp. If performance to $ is a consideration then a correctly spec'd 9.5" PTC converter will make a bigger difference most of the time.
when i ordered my ptc 9.5 from dusty i told him my futrue plan was to be running the billet dbb 6765 so he built my converter accordingly, as of right now i have a ta-49(for Sale) and have a pt-54 sitting around just need a wastegate for it and im gonna see how that runs with the converter but eventually ill be buying a 6765 dbb
Have faith in Dusty. He knows his chit. Best converter spec'r out there for small ci turbo applications imo. Be sure you run the engine as you told him you would. If you try to run 18 psi on a converter that was spec'd for 28 it will pull the engine out of the powerband.
for sure.... i dont think i told dusty what psi range just what turbo i was going to use but i plan to use as much boost as i can
i heard with the billet turbos they dont start making huge power until about 21 psi??
GNBRETT
Pelennor Fields
- Joined
- Feb 8, 2004
u mean 31
for sure.... i dont think i told dusty what psi range just what turbo i was going to use but i plan to use as much boost as i can
i heard with the billet turbos they dont start making huge power until about 21 psi??
The compressor wheel wont matter much if its a 3 bolt and alky injection is used. The exhaust side is the problem. Trust me on that. It will make power lower than 21 psi cast or billet. Ill forward you some .gct files you can look at from a couple of my passes at 750+hp with a 66mm cast wheel. You will notice the charge air temp is only about 11-12 degrees above ambient at 6200 rpm and 26psi:biggrin: I am back pressure limited at 26psi and an HD actuator
Yeah. The compressor is capable of moving way more air than the ex housing will flow causing a huge bottle neck if your engine is capable of using all the air. Back pressure rises as boost/rpm increase and push the puck off the seat. You can actually see a slight downward taper of boost in 3rd as rpm increases. I have a S/GTQ turbine with a Precision .85 housing. I need to add in my AMS 1000 external controller with CO2 charge to hold it shut. Im going to put in a line and data log backpressure too. Im guessing its over 60psi at 26psi manifold pressure at 6000+ rpm at 750-800hp. TSM sees 80+psi at 950hp with their 3 bolts. They are using a lot of pressure to hold the gate shut.
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