More power 6776

Ttype6

Well-Known Member
Joined
Aug 17, 2004
Since I bolted a bigger engine to my 6776 S cover with a Precision .63 turbine housing,my spool up is very fast resulting in zero traction in first gear. If I could find an H cover and a .85 A/R turbine housing, would it be a simple bolt on? While it probably would have been a bad idea with my smaller engine to put a .85 AR housing on, I think the slower spool and less back pressure would be a good thing for me now.
 
Are you on the stock ECU or an aftermarket one? Internal or external gate? Any boost controller?

I am on a Holley Dominator with an external gate and I have been playing with ramping the boost in to not blow the tires off. This could be done with other ecu's and boost controllers too.
 
Are you on the stock ECU or an aftermarket one? Internal or external gate? Any boost controller?

I am on a Holley Dominator with an external gate and I have been playing with ramping the boost in to not blow the tires off. This could be done with other ecu's and boost controllers too.
I'm very up to date on external wastegates and how to ramp the power in with the right electronic boost controller and I have my eye on the boost leash controller, but I really just want to know if I can simply bolt on a different compressor cover and turban housing or if something else would have to be modified on this turbocharger to do that because along with ramping in the boost with a boost controller I also figure there's some more power to be had with an 85 exhaust housing and maybe even a compressor cover but most importantly along with lowering back pressure, the 85 turbine housing would help my boost problem and should give me a little bit more power by reducing the back pressure.
 
In the past I swapped went the opposite way from .82 to a .63 to make a turbo less lazy on the street. As long as the exhaust housing is cut for your exhaust wheel I don't see why you couldn't swap it. The compressor cover is probably much bigger of a deal. If the H cover has a different backing plate vs the S cover it would require a lot more work.
 
Since I bolted a bigger engine to my 6776 S cover with a Precision .63 turbine housing,my spool up is very fast resulting in zero traction in first gear. If I could find an H cover and a .85 A/R turbine housing, would it be a simple bolt on? While it probably would have been a bad idea with my smaller engine to put a .85 AR housing on, I think the slower spool and less back pressure would be a good thing for me now.
Simple answer is no
the .85 ex housing will
But the larger compressor covers usually end up right on the water pump hose and we modify them to allow "spacing" for the hose.
I ran a big turbo on the hose and it did spilt not once but twice.
So I will save you that really fun experienceπŸ˜‰
You can try the .85 to slow things down and drop pressure.
I wouldn't bother with the cover on that turbo personally as a 67 mm cast comp wheel from years ago on that turbine wheel is probably all in even on the smaller compressor cover and the pte .63.
You have to try the ex housing and see
But inmo your turbo is the restriction on your very nice build.
controlling the turbo will be your best solutionπŸ˜‰
If you stay with that turbo or upgrade setting up your boost control will helpπŸ‘
 
But inmo your turbo is the restriction on your very nice build.
There's no doubt about that. I was just wondering if the 85 housing might make a little bit more power because I'm sure it wouldn't hurt me down low. I feel like when I bolted this bigger engine to this turbo, I got a similar increase in turbo response that a guy might get with a 231 to 235 cubic inch engine going from a 6776 to a precision 6465. I feel like if I go from this 6776 to a work turbo 6465 with an .85 exhaust housing, I'll see another increase in response time but with more power which will still mean that I have traction problems and absolutely, I'll be getting an external wastegate and CO2.
 
In the past I swapped went the opposite way from .82 to a .63 to make a turbo less lazy on the street. As long as the exhaust housing is cut for your exhaust wheel I don't see why you couldn't swap it. The compressor cover is probably much bigger of a deal. If the H cover has a different backing plate vs the S cover it would require a lot more work.
I no longer have lazy on the street since I bolted this bigger engine to this 6776 and I think that I did hear somewhere along the way that the compressor cover would be very complicated.
 
There's no doubt about that. I was just wondering if the 85 housing might make a little bit more power because I'm sure it wouldn't hurt me down low. I feel like when I bolted this bigger engine to this turbo, I got a similar increase in turbo response that a guy might get with a 231 to 235 cubic inch engine going from a 6776 to a precision 6465. I feel like if I go from this 6776 to a work turbo 6465 with an .85 exhaust housing, I'll see another increase in response time but with more power which will still mean that I have traction problems and absolutely, I'll be getting an external wastegate and CO2.
On your combo.
With the new turbos
staying 3 bolt
70/71mm turbine wheel
.85 ex housing
And nothing less than a 67mm compressor wheel.
Pte 6870dbb is a nice turbo.
67/71 comp triple bb is amazing.
but you could do 68/69mm on compressor no problem.
I loved the 6971 triple bb from comp😎
 
I no longer have lazy on the street since I bolted this bigger engine to this 6776 and I think that I did hear somewhere along the way that the compressor cover would be very complicated.
Your motor called me and wanted me to send you a bigger turboπŸ˜‚πŸ˜‰
 
Just a few idle thoughts....

A really lively turbo is just fun IMO, you have to be careful that it doesn't spool so easily that the pressure in the trans doesn't rise enough at light throttle.

I agree that good boost control will make the car more driveable.

Stickier tires might be a nice addition, when i had my stroker setup years ago BFG drag radials were my daily tire (255/50-16 on TA fronts). They really worked well as a daily tire, damp roads and light rain were fine, heavy rain not so much...

A larger A/R turbine housing should make the turbo less fun (less responsive), if the turbo has been in use for a while it may not come apart easily though.

Bob
 
i see this in your sig: " Precision 5 disk modified by Turbo Buick Performance"

what was done? (asking for a friend )

Bob
 
i see this in your sig: " Precision 5 disk modified by Turbo Buick Performance"

what was done? (asking for a friend )

Bob
Dave essentially modifies it so it is the same as one of the two versions he sells. if you took my converter apart, you would find the same parts and modifications inside it that you would find inside his and the most obvious part would be the pump because you can see the difference from the outside with its negative fin angle. The coupling is so much better that the acceleration is very obvious. The first time I drove the car after installing it, the car scared me for the first time since I owned it. The vig didn't couple well at all, but I wanted to keep the five disc setup.
 
Just a few idle thoughts....

A really lively turbo is just fun IMO, you have to be careful that it doesn't spool so easily that the pressure in the trans doesn't rise enough at light throttle.

I agree that good boost control will make the car more driveable.

Stickier tires might be a nice addition, when i had my stroker setup years ago BFG drag radials were my daily tire (255/50-16 on TA fronts). They really worked well as a daily tire, damp roads and light rain were fine, heavy rain not so much...

A larger A/R turbine housing should make the turbo less fun (less responsive), if the turbo has been in use for a while it may not come apart easily though.

Bob
I agree with every thing you've said here and my car is extremely fun and my tires are 275/ 60 radial pros. In some of my data logs the tires spin from 45 to 85 MPH ,but you cant tell because the car remains nice and straight. The car would be very dangerous without them. I'm actually very hesitant to change anything ,but it only makes 700 HP. I just can't have all of my neighbors and people I'm never going to meet laughing at me. I never allow it to make alot of boost at light throttle. I alwas go to WOT.
 
On your combo.
With the new turbos
staying 3 bolt
70/71mm turbine wheel
.85 ex housing
And nothing less than a 67mm compressor wheel.
Pte 6870dbb is a nice turbo.
67/71 comp triple bb is amazing.
but you could do 68/69mm on compressor no problem.
I loved the 6971 triple bb from comp😎
You've spoken so highly of the 6465 in the past.
 
You've spoken so highly of the 6465 in the past.
Yes
Its a really nice turbo
But the new turbos can spool just as fast while being much bigger on the compressor and turbine wheel while running the larger ex housing. With hundreds of horsepower more on tap while running low backpressure πŸ˜‰.
On one of my cars I was running a 69mm billet single bb turbo and I would switch out the turbine side from a 65 to 68f1 wheel and had a .82 ported ex housing.
I did also switch out to .63 ex housing to do testing.
Switched out to a 69/71 triple bbb with an .85 pte ported.
The 6971 spooled faster and made over 200hp more,even vs the smaller 65 turbine wheel in a .63😎
Turboland has never been betterπŸ‘
 
Yes
Its a really nice turbo
But the new turbos can spool just as fast while being much bigger on the compressor and turbine wheel while running the larger ex housing. With hundreds of horsepower more on tap while running low backpressure πŸ˜‰.
On one of my cars I was running a 69mm billet single bb turbo and I would switch out the turbine side from a 65 to 68f1 wheel and had a .82 ported ex housing.
I did also switch out to .63 ex housing to do testing.
Switched out to a 69/71 triple bbb with an .85 pte ported.
The 6971 spooled faster and made over 200hp more,even vs the smaller 65 turbine wheel in a .63😎
Turboland has never been betterπŸ‘
It used to be such a trade-off that it was hard to make a decision, but I guess it's a no-brainer now. I could tell people " I could turn this thing up and make a thousand horsepower but I don't really like to show off ". I'm starting to see the light.
 
It used to be such a trade-off that it was hard to make a decision, but I guess it's a no-brainer now. I could tell people " I could turn this thing up and make a thousand horsepower but I don't really like to show off ". I'm starting to see the light.
There is no trade off nowπŸ˜‰
I sent you a pm.
There are things that must compliment the new turbos
 
Before I put the Tnetics 6465 on I had a TE45A . It was a night and day difference . The 6465 spooled way faster and was really fun to drive . After Dave Husek built my new motor I used the same 6465 and the car ran good but it was holding the motor back . Mr Spool suggested the Comp 6767 tripple BB .85 ar . He drove and tested the car and found that there was high back pressure , so we switched to a 71 ex housing and went to a 3.5" downpipe . Back pressure went down , HP went up ...a lot and it spools faster than it ever did on the 6465 . Mr Spool can fill in the details .
 
Before I put the Tnetics 6465 on I had a TE45A . It was a night and day difference . The 6465 spooled way faster and was really fun to drive . After Dave Husek built my new motor I used the same 6465 and the car ran good but it was holding the motor back . Mr Spool suggested the Comp 6767 tripple BB .85 ar . He drove and tested the car and found that there was high back pressure , so we switched to a 71 ex housing and went to a 3.5" downpipe . Back pressure went down , HP went up ...a lot and it spools faster than it ever did on the 6465 . Mr Spool can fill in the details .
I might have another problem, my intercooler. It's an old Kenny Bell big boy. Not the first design, but the second much smaller design with 33 vertical tubes.
 
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