Looking for the right turbo

[jasjamz]

Yullose, shot you a PM.

Where is Patrick...:biggrin:

 

[slo-joe55]

converter is a Art Carr 9" NL 3800 stall.

 

[jasjamz]

http://www.turbobuick.com/forums/tu...recision-turbos-new-turbo-listing-buicks.html

Its a tough call...

 

[slo-joe55]

Not sure how much compression.

 

[slo-joe55]

I sent an e-mail to Patrick @ PTE to get his input.

 

[jasjamz]

Make a cup of tea and be ready for a Good reply!

 

[2QUICK2B6]

The 6768 would work well on the street but will it still pull @ the top end? I am tring to see how close I can get to having the best of both worlds. Street response and top end on the track.

Yes its will support over 900hp it pulls like a freight train uptop. thats where it shines.

 

[yullose]

I think torque converter selection is pretty critical to spooling a turbo, regardless of the size.

My 70GTQ journal bearing turbo was pretty soggy with the 9.5" 5-disc Vigilante.... but after going to a TH400 and 9.5" PTC spec'd to my combo, it's actually pretty snappy now.

I couldn't believe how much difference it made.

I'd think that 3800rpm AC converter should be loose enough to spool a good size turbo. Not sure how it would compare to one of Dusty's PTC units though.

Having said that, I wouldn't hesitate to run a 70GTQ or maybe even a little larger on the street... especially with a $2k budget. I'd probably go with a billet wheel, ball bearing unit though.

I think my next turbo will be a 71HPQ...

Read this thread...
http://www.turbobuick.com/forums/turbos-turbo-related-parts/302679-71mm-billet-hpq.html

 

[slo-joe55]

I heard guys that went to the TH400 made a big differents when it came to racing. But some really missed that overdrive on the street. I agree the converter is a very critical part. I have heard some say that they swicthed from Art Carr to PTC and like the change. Any thoughts on the differencs between the two? That 6768 turbo may be something to reconsider. At the time of the engine build to acheive my goal I needed a 70 series turbo. I would need to see if that turbo would work with the present converter. My mechanic says get the biggest housing for the turbo and the converter will handle the bottom end. I see some of these car at the track they take forever at the line to spool up.

 

[slo-joe55]

Hey Guys Patrick just replied to the e-mail I sent. He is saying 70HPQ would get the job done but I would have to turn the boost up way past my confort zone (28-30 on a 250ci V6 for a high 9sec time slip). He suggested 71HPQ to get the job done. Man the price different between the J and DBB. Is the spool up really that much better or is it more to it then that?

 

[yullose]

Hey Guys Patrick just replied to the e-mail I sent. He is saying 70HPQ would get the job done but I would have to turn the boost up way past my confort zone (28-30 on a 250ci V6 for a high 9sec time slip). He suggested 71HPQ to get the job done. Man the price different between the J and DBB. Is the spool up really that much better or is it more to it then that?

Spoolup on a DBB turbo is completely different than a journal bearing.

A DBB 71HPQ would probably spool faster than alot of smaller journal bearing turbos.

The last ball bearing turbo I ran was a CPT66 with a .63 exhaust housing and it was almost "too fast" if that makes any sense. It would start spooling and making boost under light throttle, just climbing a slight grade. I thought going to the 70gtq made the car much much nicer to drive on the street.

Judging by what I've read on the 71HPQ, it looks to be the best of both worlds with huge power and fast spoolup.

 

[RUQWKNF]

Honestly, if both are journal bearing turbos, spool up should not be that big a difference, if anything, the Billet 71 HPQ should spool slightly quicker than the cast 70 HPQ.

That boost level would be pretty typical on TSM combinations. Anywhere from 24psi to 30psi is common. We are seeing very pleasing results from our customers, who have changed from the cast 70mm compressor wheel, to the Billet 71mm compressor wheel in TSM trim.

But if you were wanting slightly quicker spool up, with high nine second capability, don't rule out the new Billet 67HPQ turbo either. It's rated to support 935 flywheel hp. Your converter would spool it up as well.
HTH

Patrick

 

[slo-joe55]

Would it be safe to say that one would have to run higher boost (25+) on the 67HPQ with a 231ci motor for a low 10 or high 9 sec time slip?

 

[slo-joe55]

Thanks guys for the input.

 

[jasjamz]

Would it be safe to say that one would have to run higher boost (25+) on the 67HPQ with a 231ci motor for a low 10 or high 9 sec time slip?

Lots of variables, but I'd lean more torwards Yes.