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Discussion Starter #1
From what I can gather the T66 outflows the SP63, and full boost comes in 300-500rpms later. If this correct?

I know a lot of it has to do with the AR Housing, but when exactly will the T66 with .81 AR (i think the .81 comes with the kit) spool compared to the SP63.
 

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We tried dynoing a T66 Ptrim vs our SP63 Ptrim and the T66 made 2 more RWHP but made 80 Ft-Lbs LESS of torque due to the increase in lag. We switched the 66 to a Q trim exhaust wheel and had much better luck. It made more HP and TQ that way with LESS LAG.


I have never been a big fan of the 66 and P trim combo.


Our new SP70 - Q trim seems to spool better and make more HP than any 66 combo we have tried.



Lar
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Sound Performance said:
We tried dynoing a T66 Ptrim vs our SP63 Ptrim and the T66 made 2 more RWHP but made 80 Ft-Lbs LESS of torque due to the increase in lag. We switched the 66 to a Q trim exhaust wheel and had much better luck. It made more HP and TQ that way with LESS LAG.


I have never been a big fan of the 66 and P trim combo.


Our new SP70 - Q trim seems to spool better and make more HP than any 66 combo we have tried.



Lar
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You happen to have any dyno sheets of the t-66 with a Q-trim or P-trim?
 

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Dang, Larry! I hope people appreciate you sharing so many tuning secrets. Anytime anyone asks a question you're happy to answer even if others are liable to use that info to do business elsewhere, or even to compete with you. You a good man. :) Has Vinny Ten EVER given away a free bit of useful advice? Not that I've ever heard.

Steve
Sound Performance said:
We tried dynoing a T66 Ptrim vs our SP63 Ptrim and the T66 made 2 more RWHP but made 80 Ft-Lbs LESS of torque due to the increase in lag. We switched the 66 to a Q trim exhaust wheel and had much better luck. It made more HP and TQ that way with LESS LAG.


I have never been a big fan of the 66 and P trim combo.


Our new SP70 - Q trim seems to spool better and make more HP than any 66 combo we have tried.



Lar
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Hrm!

I'd be interested in seeing sheets comparing the T-66, SP63, and the new SP70. The SP63 is about $400 more than the T-66 I was considering but if the 70 outspools the T-66 I might just bite the bullet. Would be interesting to see a sheet that showed the benefits of the SP63 over the T-66 too as it would be much easier to justify the cost delta then :) I could've sworn there was a page of SP dyno sheets out there but I'm not seeing them now that I'm looking - did I miss them?

As a side comment - how come no one seems to water cool their turbos? Stock ports are there but reading soe of the posts it seems that people cap those off. Is there a particular reason? Just seems like a good idea to watercool for reliability. If everyone is capping off the lines there mus tbe a good reason I'm unaware of...
 

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SP70 OUTSPOOLS A T66!?

Does that make a pretty significant amount of more power than the T66 Too?

Hmm... If a T66 is suitable for an Auto (thats about the limit from what I understand for good streetability)... Would a SP70 be ok on an Auto with TC as a Daily driver?... Would the lag be bearable... I hear of people with T66s on Autos now and then... so what do you think Larry?

Also... what kind of RWHP would I put down with a SP70 with 264 cams, your intake manifold, and everything else necessary to run it well.... what staul would I need.. 4000rpm?

Let me know if you think this would be overkill or a good setup for a DAILY driven supra which wants to still be able to kick some American Muscle ass FROM A STOP and still lay down the smack on the highway... Im very interested in hearing what you have to say about this.. because Im getting excited :D (hopefully for good reason)

Thanks!
 

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LESS lag with a Q trim? I thought the Q trim was a more aggressive exhaust wheel?!?! Now I'm really confused. Damnit, I just bought a P trim T66! I've seen some pretty impressive dynos of this turbo too... Maybe I should have spent the extra $$ for an SP63.

poweraddict, the RPMs turbos spool at is mostly effected by the turbine side (ie the trim and a/r). The rotational inertia effects the time it takes to spool past the boost threashold.

pooshda, sorry there aren't any magic turbos that I've ever heard of :) Unless you want a good flowing exhaust side (which means its going to spool later) to go with that SP70, its not going to make a lot of power. Now I don't know the details of it at all, but if you look at Steve Vache's site, there are dyno graphs of a SP70 .81 and a SP63 .81 on the same car, Al S's. The SP63 makes a bit more power (~560rwhp) at 1 psi less (19) boost. The SP70 compressor likely needs more airflow to be effecient than the stock cams (and maybe a .81 housing) can support. I'm sure Larry will correct me if I am wrong, but me thinks the SP70 probably likes a LOT of flow :)

Larry, do you find the larger a/rs make more power at every boost level, or just high (22+) boost?

BLKMGK, I ordered a water cooled turbo. Corky Bell claims they last about twice as long, and turbo timing isn't as important. Plus I didn't want the thing cooking my oil road racing. I called SP about it, and they said $100 more and I would have to wait a week or two longer for it (SP63 .70). I didn't want to wait, and the dyno sheets I've seen show the T66 to be about equivilent to the SP63. Ryan Woon has made 655 on the .81 P trim T66, with 27.5 psi. Of course, the T66 has a larger and probably heavier compressor wheel (look at the measurements on Steve's site, the SP63 has a small exducer).
 

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My SP63 has a water-cooled center section. I told Larry what I wanted and he sent my SP63 with the water-cooled center section, braided stainless steel water lines and the fitting for my EGT probe already installed. The pricing for these extras was very reasonable and everything fit great.

Later, Steve
 

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No they are not ball bearing turbos. Ball bearing turbos cost more, don't seem to make much difference to performance, and can't be rebuilt. A non ball bearing turbo will last at least 100,000 miles so I don't really see the point. For the additional price of a ball bearing turbo you could almost have your turbo rebuilt after 100,000 miles and be ready for another 100,000 miles.

Later, Steve
 

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I agree. Or more likely, you'll use that saved money to upgrade to the next latest, greatest turbo. Who's going to keep the same single for 100K miles? :)

Steve - bought a BB watercooled T-64 and like it just fine, but 4K miles later switched to a non-BB, non-water-cooled SP74.

Steve Jarvis said:
No they are not ball bearing turbos. Ball bearing turbos cost more, don't seem to make much difference to performance, and can't be rebuilt. A non ball bearing turbo will last at least 100,000 miles so I don't really see the point. For the additional price of a ball bearing turbo you could almost have your turbo rebuilt after 100,000 miles and be ready for another 100,000 miles.

Later, Steve
 
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Discussion Starter #14 (Edited)
Very interesting...

I will agree with you that from a Performance perspective they won't produce more power but they do spool faster so you will come on boost faster and seeing as how laggy your cars are Im suprised your not using them.

A member on Turbobuick said he went from a 58mm Non BB turbo to a 66mm BB turbo with no other changes and the car spooled FASTER with no other changes.


Nobody has done a back to back on a dyno to see if they spool quicker?


Also, Id like to see a aftermarket turbo last 100K miles that gets raced often. Never Happen..
 

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I don't think anyone with a MKIV has seen a BB turbo that spooled any faster than the SP and PHR turbos that are currently available. Single turbo MKIV owners tend to be fairly affluent and if it made a major difference you would see a lot of BB turbos on Supra's. A reasonable sized single will spool as fast as the stock twins in TTC mode so I don't know why you would consider them laggy. If our car are laggy than it's because they are only 3.0 liters. A BB turbo is not going to change that.

Later, Steve
 

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Here is a copy of a post from the big list on BB turbos:



>Ball bearings have been used off and on since the 30's. It's certainly
> >possible that ball bearing turbos handle axial loads better than plain
> >bearings, but in terms of friction, ball bearings have inherently more
> >drag than plain bearings especially when they are flooded with oil. The
> >real question is how much axial loading is there, and why. There are
> >lots of methods of controling axial loads with ball, needle, tapered
> >needle and roller bearings.
> >
> >As far as the stories, if you go to Garrett's site, they claim ball
> >bearings spin up faster. They make no claims at all about longer life,
> >better axial load control, or any of the other things I have heard about
> >ball bearing turbos. If I really wanted to know about plain vs. ball
> >bearings, I'd ask a truck mechanic (one with a few smarts, not like some
> >of your typical diesel techs). Truckers put more stress on their turbos
> >than we can imagine. Just think about what it takes to haul 40,000 lbs
> >up a hill like the Grapevine on I-5 in CA. That turbo is screaming its
> >little heart out all the way up the hill...we're lucky (and flat hauling
> >ass) if we get a continuous run at full load for a whole minute, they do
> >it for 5, 10, 15 minutes straight. That's a real workout. If ball
> >bearings are so superior, the trucking industry wouldn't even bother
> >with plain bearing turbos. Last I heard, the jury is still out there
> >too.
> >
> >Lance
> >'93 TT 6 speed Coupe




Has anyone tried putting oil pressure into a BB turbo and comparing it to regualr bearing turbo?? The regular bearing turbo spins easier! It is only when the two turbos are dry does the BB spin easier. Think about it, less surface area bearing wise. I have personally never seen a BB turbo spool any faster and with the new 360 degree thrust bearings available I see no reason to use a BB turbo ever from a reliability standpoint.


Lar
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I was wondering, whats the largest turbo SP makes? the SP74? also, i know a few people who have the Big Thumper line of turbos on their mustangs (some have the 88, one has a 91, and one has a T100) the Greddy T88 isnt the same size as the 88mm Thumper is it? Just find it hard to believe that people are driving around with an 88mm turbo on their supra, but maybe im wrong. Thanks for the help guys
 
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Discussion Starter #20
I dont think people are having issues with the reliability between a BB and NBB I'm wondering more about spooling.

I have spoken to 4 different Turbo Vendors and its split 2-2 for and against.



Say whats a typical SP63 NBB turbo go far? Just ballpark?
 
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