6870 DBB .85 A/R 3 Bolt Buick Housing-Backpressure Data

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he compressor wheel can move some air, but only when properly matched with a better flowing turbine housing, the larger H compressor cover (although not offered on the 6466),
i have run a billet bb64 with both a 68 and 65 turbine wheel and the larger cover with a 3 bolt ex housing and was wondering why pte didnt offer the larger cover on their 64.nevertheless,there are 9 sec pte 64s out there and all go faster than low 10s and make more than 18 psi.
 
IMO, 274 - 280 CI is large for a 3-bolt "anything" turbo, in order to maintain proper efficiency and control back pressure, while making good power past 900 rwhp. Sure, some have and are doing it with the 3-bolt housing, but we learned years ago with testing the old school PT88 with the Outlawed "Cantaloupe" 3-bolt .96 turbine housing, what the limits were.
are you sure?i have seen some backpressure readings off a 900+rwhp buick with a .85 housing and its nothing crazy high,nowhere near 2to1.
 
are you sure?i have seen some backpressure readings off a 900+rwhp buick with a .85 housing and its nothing crazy high,nowhere near 2to1.

Their (PTE's) current turbine wheel tech has drastically changed things from when I left in 2010. And to be honest, I've been out of the loop with what's currently being accomplished with the new tech. I'm still playing catch up with the real 3-bolt players and their antics. I'm truly loving that guys are getting a grip on back pressure with the .85 3-bolt housing. Forever, it was the bottle neck with what turbine wheels we had to choose from.

One things for sure, the compressor wheel and turbine wheel technologies from all of the big 4 companies, (PTE, Garrett, Work & BW), are really making these combos scream today.

-Patrick-
 
'm truly loving that guys are getting a grip on back pressure with the .85 3-bolt housing. Forever, it was the bottle neck with what turbine wheels we had to choose from.
thats interesting.the 3 bolt can support alot of power, more than most guys can create,although alot more are running good motors.
 
Howdy Fellas,

Very interesting thread...

I currently have a 2010 6768 THS turbo 3x2 cover. My combo is 250 stroker with Ported TA Alum Heads 214/214 DLS cam. I have been fighting back pressure with this turbo and it seems to have run out of steam @ 32/33 psi..

I made a pressure sensor setup that goes into the stock narrow band o2 location and the sensor is located near the throttle body water lines.. I'm currently using a fast 0-100 psi sensor and i use the oil psi channel in the XFI for datalogging it.

Anyhow what i found was that i'm seeing 68-72 psi back pressure @ 32-33 psi boost and it wont make no more boost. Im using manifold pressure on the external 46mm gate and controlled with a boost leash. With 2 psi on the gate with the springs i have in the gate it will make 25 psi... i can command 28-33 psi on the gate and get no more boost..

So the question is will the 6870 help me? or will i be in the same place being that both turbos have the 68 turbine wheel

now i have been 138 mph @ 3680lbs. with my combo.

i also wonder if the 6766 is more efficient over the 6768 or is precision just used the 66 wheel since it was being offered in the 6466?

Thanks for any info
 
now i have been 138 mph @ 3680lbs. with my combo.
at 3950lbs i had a 64/68 large cover 3 bolt .63 housing go 137 at 28psi with iron heads.playing around with the wastegate i could get it to 31psi.after that the turbo made alot more when turned even higher, but i had to seal the gate it shut:)
 
cant see you seeing backpressure issues with a 68 turbine wheel it is good for alot more than a 66


If thats the case i wonder why they dont offer the 6768 turbo anymore......They only offer the 6766......

From what i understand its a turbonectics turbine wheel?

i dont think adding c02 will help performasnce wise....yes it may help with making more boost but i'm already at the 2.1 backpressure..

im wondering if the 6870 turbo uses the same turbine wheel?
 
The 70 turbine wheel is different than the 68. It is larger and a better wheel all around. Precision began using their own wheels, that is why they stopped using the turbonetics wheels. The orginal 62 and 65 were turbonetics sourced as well. My 7168 had 2 psi backpressure more at 25psi boost, but still wasnt 2:1 and this was at 920rwhp.
 
dont think adding c02 will help performasnce wise....yes it may help with making more boost but i'm already at the 2.1 backpressure..
doesnt mean it wont go faster.i have seen cars make way more than 2to1 and go faster.it depends on your approach,if you want lower bp you may have to look into other areas.but the 68 turbine wheel is not the reason
 
f thats the case i wonder why they dont offer the 6768 turbo anymore......They only offer the 6766......
rob pretty much explained it,also the 68 turbine wheel is quite pricey and is considered an upgrade.you can still get them from tnetics.i run their billet 69mm wheel
 
Does this mean they are going to phase out the f1 turbine and use the cea?
not to my knowlege,you cant get a 68 wheel in a pte anymore but you can on a tnetics,but in fairness with the 70 turbine wheel from pte you would not need to.after a 70 turbine wheel or 68 f1 comes a 75mm turbine wheel which both offer.but there are all different options out there wheelwise.it seems like alot of them overlap.the truth is they all make power.the tnetics stuff is way underated and the pte stuff speaks for themselves,there ratings are out there and very easy to find they make big power with generally smaller units.
 
Does this mean they are going to phase out the f1 turbine and use the cea?

With both companies (PTE & T-netics) being owned by the same parent company, the business model would make since to downsize production costs and consolidate/utilize common components between the two. But that is all up to the bean counters to figure out. I'm sure demand would drive that decision big time. And with the costs going up to have stuff manufactured in the various asian countries, hopefully this will drive production back home to the US. IMHO, T-netics stands to gain the most benefit from PTE's continued fantastic R&D work. So here's a tip. The new products displayed at the up coming PRI show from both companies will be the clue. So keep your eyes open at the show.

We, us, our Turbo Buick community, are finding out these types of results by our own real world testing. Other shops report back these results during the R&D phase, before anything new ever hits the market. We're kinda left to our own devices to figure out what works with our combos. Mainly because there are very few dedicated Turbo Buick shops left in the country. And the ones that are, have had to branch out and support other platforms because we're such a small group. For years, this specific information (testing old vs new & boost vs back pressure vs track results) were always a closely guarded and sometimes proprietary secret. I appreciate all of you guys that are actively testing and publishing your results, as it only helps our community when it comes to making an educated buying decision.

Carry on.

-Patrick-
 
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