New Turbo 6766 Dbb or not..that is the question

G

GetOwnedVette

Active Member
Joined
Jun 13, 2006
So before the car is even done I'm considering changing turbos.:p I currently have a GTQ-70 which is a little much for a 3000 stall. I could send it to Precision and have them stall change it for $200 or so but everything is already done and buttoned up down there and I just dont feel like taking it apart.

Any who im thinking of ordering a New (since finding these used is impossible) Precision 6766 CEA. Billet wheels are all the hype right now and are a hype for a reason. My question is DBB or not?? Its a pricey feature and im just wondering how big a bonus it would be. Considering it will be an E-85 car and now on a 67 wheel the 3000 stall should be just fine. I hear spool times are a bit quicker on the corn so is the $800 option worth the money? Any real world experiences and input would be great :)
 
Keep the converter a 0 pump. A 6 or 7 pump will slip like crazy. A friend of mine has a 6765 billet JB with a 10" 2800 stall on a 231. It spools great. I have driven TSS cars with 66gtq turbos and 0 pump Vigilante converters on stock cube engines. They spool fine. A 6766 should spool faster. What are your goals?
 
Goals have always been low 10's floating around 600hp. I like the 3000 stall that is currently in the car....and the car gets a lot of street time. Guess I'm just trying to justify the 8 bills on the DBB unit vs the journal. Meh im thinking the journal 67 will need at least a 3200 stall still..sigh...Guess its just time to break out the wallet again. I swear when this car is done I wont know what to spent my cookie jar money on. :cool:
 
Put it like this...... if you buy the JB version..... you will wonder how much difference the DBB version would have made.....if this happens a time or two... it would have been worth the coin to step up on the front end.

FWIW, with a goal of low 10's, you are looking at a turbo that is capable of high 8's. If this car sees mostly street duty, IMHO, I'd consider the new 6466. It makes almost as much power, and should spoolup a little quicker. Heck, the 6266 should get you there before 30 psi boost.
 
There's a bazillion dollars worth of parts on the car already, get the DBB version. :)
 
The 6466 is $1909 on Precision's website.:eek:
 
Pronto said:
The 6466 is $1909 on Precision's website.:eek:
Click to expand...

It is the latest in their compressor wheel and exhaust wheel design..... Hence the 900 hp rating..... It also only can be had with the DBB version unless they changed it.

I expect this version of their CEA design to trickle into some of the other already billet wheeled turbos.....should be interesting. I wouldn't be surprised if they could get 1000 hp out of a 67 soon.
 
Only low 10's? Just order a 6266 journal. There's a lot of performance gain with a better converter. Spend the $ there.
 
bison said:
Only low 10's? Just order a 6266 journal. There's a lot of performance gain with a better converter. Spend the $ there.
Click to expand...

Well that's the "initial goal" :p I shall slowly see what breaks along the way of trying to go faster each week at the track :) What do you suggest on a converter? I have a Precision 3000...and after talking to Cliff (rip) he said around 550 hp and 25-26 psi he started blowing through the Precision pretty badly....said he would for sure see 9's and 600+ with a PTC. I also like your way of thinking Blazer...I will always wonder "what if" if I go journal.
 
Im running a tnetics billet 64/68bb with a ptc 9.5 3200,you cant even see the boost gauge move.the proper converter should not need the bb.
 
GetOwnedVette said:
Well that's the "initial goal" :p I shall slowly see what breaks along the way of trying to go faster each week at the track....snip
Click to expand...

We call that "scope creep" in the Engineering world.... LOL

IMHO, you could (theoretically) run 10.0 with a 6766 0r a 6266.... both would get you there. The 67 would probably take 23-25 psi to do it (maybe a little more since you are running iron heads).... depending on what mods and how good of a 60' time you get.....and the 6266 would could take closer 30 psi (maybe a little more since you are running iron heads). The 6266 would spoolup faster and have better street manners and would probably feel quicker red light to red light....... BUT.... if you wanted to take your car beyond the 10.0 very far..... the 64 or 67 would be a much better choice.

If you are considering a converter change... do it when you do the turbo and get Dusty at PTC to spec the converter out based on your whole combo and what you are planning to do with it. I'd think you'd be looking at a 9-1/2" N/L converter..... you can't go wrong with a PTC from Dusty.
 
6266 or 6766 will likely take the same boost to run 10.0 since neither would be anywhere near their max mass flow. Probably around 25psi if the engine is somewhat efficient. Running a larger compressor than needed does nothing for power. At 2.8:1 pressure ratio the 6266 could flow 78lbs/min. That's enough to run 9.70 in a full weight TR with an ok 60'.
 
Well as I stated above getting my feet wet at low 10's would not make me sad. I built it to go faster hence wanting a little bit larger turbo just in case...dont wanna drop that kinda money ever again. I gave in and ordered a Precision 6766 in ball bearing w/ polished PH cover. We will see how it goes with my 3000 Lockup. Next things on the list will be seeing how this convertor plays and either way go with something more suited for the combo. PTC 3200 NLU? Im still not bright when it comes to this Lu/Nlu business. I try to read up as much as I can on it. Could ask my old man but he helps me enough with my questions :p Along with that I definitely wanna build a bulletproof rear end. That will probably be over winter though..unless this 8.5 blows up :D
 
i've ran both LU and N/LU converters and the non-lockup has WAY tighter coupling. In 3rd gear I have less than 3% slip. My old Vigilante had around 22% slip. If you got your eyes on 10's, don't even bother with a lockup converter. You'll blow right through it.
 
toomanymodz said:
i've ran both LU and N/LU converters and the non-lockup has WAY tighter coupling. In 3rd gear I have less than 3% slip. My old Vigilante had around 22% slip. If you got your eyes on 10's, don't even bother with a lockup converter. You'll blow right through it.
Click to expand...

If I were to go with a new PTC N/LU what else would i need to change?
 
You must log in or register to reply here.

Similar threads

Mike Swentzel
Vacuum brakes & Proportion Valve Question
Replies
13
Views
952
Mike Swentzel
Mike Swentzel
ttypewhite
Precision 8285 DBB turbo for sale
Replies
5
Views
1K
ttypewhite
ttypewhite
J
Found an 87 GN that has been sitting for 10+ years in storage..
Replies
10
Views
563
granitestategn
G
H
Best Non Lock-up Torque Convertor Brands
Replies
15
Views
1K
V6sleeper
V6sleeper
D
Electrical GN dome light question
Replies
7
Views
575
Dhos1
D
Top