General comment on stall and BB turbos

[PowerKraus]

First forgive me for asking a really dumb question, but I am getting up to speed on all the changes in turbo technology; advances in tech since I parked my buggy back in the 90s. And I want to dril down into more detail to understand why I can go larger.

So, generally speaking,you can get away with a larger turbo, than say you could back in 1995, due to BB turbos and improved flow of housings and trims. With my combo (AC nl 16930 3200 stall, ported heads/intake, and 3.90 gears) I am no longer maxed at the TE63 I installed the mid 90s.

Of course with upgraded injectors and fuel delivery. I can burn ships, and am running an MDS4-DIS and MAFT. I also have a FM and PMAC tranny.

From a previous post, it was said I could get away with a 66/67 as long as it is BB (at least on one side), as all the advances allow the larger turbos to spool much quicker.

I am just looking to confirm the 'why' I can go larger.....and I can do this because of the improved spooling of the new turbo designs. Correct?

And if I do not mind a little lag, and more of a top end charge, would a 70 just be stupid for me to consider; wouldn't think the 3.90s would let me get away with just a little more turbo. BTW, I am more interested in 1/8th mile and street performance.

From my searches, it seems all the good turbo stuff has really come into its own within the past 18 months

Thanks guys!

 

[bison]

Depending on your power, and tire height the 3.90's may not help your performance in the eighth. It may actually hurt it. You can run the 16930 with just about any p-Trim up to a 72 with a little lag and a .63 ex. I ran a .85 on a friends with a 67 and it wasnt too bad with a 3000 stall. I wouldnt do it with a q-trim though unless you go for 3800 stall at zero boost,zero vacuum.

 

[PowerKraus]

bison,

Appreciate it. Between the comments I've received (http://www.turbobuick.com/forums/turbos-turbo-related-parts/201649-what-hot-turbo-street.html) and forum searches going back about 18months...I've collected great 'intel'. It certainly looks like a BB66/67 is a perfect choice, and a 70/72 might be pushing it. But, after all, changing converters (as I am already set-up for non-lockups) is a peice of cake.

Again, thanks !

 

[Dr.drivability]

Powercrause, I went from a TE61 to a GT67BB and noticed one H*** of a difference on both the top and bootom end! I absolutly love this turbo.I bougut it from Mike at full throttle. The unfortunite thing is I only got half a pass on it, that I'm sure woud have been in the 10's before I scattered the short block. It spooled better and had very long legs! Can't wait to see how my new stroker short block does with it. Go Ball bearing!!!!

 

[PowerKraus]

<<Go Ball bearing!!!!>>

dO YOU MEAN GO NADS GO ?

 

[Dr.drivability]

The initial investment is more costly, but, with lots of tuning, I think this black beast will turn a 9something with this turbo. and give me many years of service.

 

[bison]

The initial investment is more costly, but, with lots of tuning, I think this black beast will turn a 9something with this turbo. and give me many years of service.

Is yours a P or Q?

 

[JayC]

With the converter you have, I would go right to a GTQ71 myself.

 

[Dr.drivability]

I think it's a Q trim, but i'm not sure. It's the one Mike advertises on his web site with the "S" cover. I know it's not cheap, but it's worth every penny!! Mabee Mike could post and let us both know

 

[bison]

I think it's a Q trim, but i'm not sure. It's the one Mike advertises on his web site with the "S" cover. I know it's not cheap, but it's worth every penny!! Mabee Mike could post and let us both know

If its a Q the exhaust wheel will be sticking out of the opening on the exhaust side if looking down at the unit. If its a P the wheel will be in the housing. There are pics on here somewhere.

 

[PowerKraus]

With the converter you have, I would go right to a GTQ71 myself.

Hey Jay,

Is there an option for a particular size exhaust housing? BTW, the 63 is the one you sold me. Still runs great, but it will be in the parts section soon to try to offset some of the costs of the 60/65lbers and the new turbo.

Any real trouble on boost control with the old 'th' downpipe? If I recall...there was a particular 'nickname' for it:tongue:

 

[JayC]

You can use a HD actuator and probably be fine. I don't really like the actuator setup personally but it works for a lot of people so not much you can say about that.

I would go with the lower AR ratio myself (.63 I believe is what the PTE housings are) as I dont think you have enough converter to spool the larger one and even if you do, I think the gains would be minimal.. maybe 1-1.5MPH on the big end.

The GTQ stuff is pretty badass.. its about all Ive been using for several years.

 

[Reggie West]

If you do go to a bigger turbo I would seriously consider a bigger downpipe.

Jasons 5 inch monster will work the stock actuator, but at some point you may have problems controlling that big of a turbo with a stock actuator.

Since you already have the converter I would have it restalled to 3800. With 3.90 gears you can run a 28' tall slick and that will help the 60 ft times.

Just my 2 cents

 

[PowerKraus]

Reggie,
Good point, thats what I read between the line with Jay's comment. What I have may work, better boost, litter more stall, and a bigger downpipe with bring 'better, gains.

Thanks guys !

 

[turbo buicks]

Of course with upgraded injectors and fuel delivery. I can burn ships,...

dont know about that