Precision Billet Turbos

[azzada1]

What size rear housing? Im sure it should have more left in it at only 26psi

[Buraz]

.84 housing!! Simply won't take more boost. You wind in 30psi+ and it just drops down to 25-26psi. No restrictions in cooler etc, even tried a plazmaman 100mm cooler and it's still same.

[SimonR32]

6 hours ago, Buraz said:

What's everyone's results with 6262 precision??

My is out of puff at just under 440kw and 26 psi on a 2.8l stroker

Mine has gone 560kw at the hubs. 440kw sounds significantly lower regardless of the dyno. Got a graph? Any restrictions?

[burn4005]

What waste gate spring are you using?

[Buraz]

Ahhh okay!! That's a big difference for sure. No restrictions whatsoever, it's a split pulse 6 boost and twin gates too. 17.5psi springs!!

 

Car hammers no doubt about it and I'm more than happy. Just thought I'd share my results with you guys and see other results

[Buraz]

[SimonR32]

For what's it's worth mine makes about 100hp more than that on similar boost... and 160hp more at 2bar

[Buraz]

Oh wow that's a massive difference!! Is it same rear housing as mine?? After talking to a few people now, this thing is only a tiny turbo and tell me it's about right.
But yours is an unbelievable result. Still a 2.6?

[SimonR32]

0.84 rear divided T4

Yeah 2.6L. I have had it on 2 different motors with basically the same result

Edited April 26, 2017 by SimonR32
Added info

[Nismo 3.2ish]

I have a PT6266 Gen 2 for sale $1500 ONO, in very good condition

 

[SiR_RB]

Mine should be hitting the dyno next week hopefully 

previous tune was 645kw at 34psi with a 7175 gt42 on a hks 2.8

few changes since last tune such as 100mm plazmaman cooler and turbo1 custom twin scroll manifold with twin 38mm tial gates,

should come on nicer now then it did with the old greddy stainless manifold

[SimonR32]

The 6262 sillyness is never ending... New cams just got the most power and torque it's ever made

[ido09s]

On ‎25‎/‎05‎/‎2017 at 10:04 PM, SiR_RB said:

Mine should be hitting the dyno next week hopefully 

previous tune was 645kw at 34psi with a 7175 gt42 on a hks 2.8

few changes since last tune such as 100mm plazmaman cooler and turbo1 custom twin scroll manifold with twin 38mm tial gates,

should come on nicer now then it did with the old greddy stainless manifold

How did it go?

I am quite interested to see how much difference a manifold makes.

I have a 6766 on a T88 Greddy manifold and have access to a 6 boost if the need arises. The car makes 460 odd rwkw @30psi on Unigroups dyno and traps 138mph but I still want more.

Have been told I should have gone the 6466 as its better suited to an RB26

Edited June 26, 2017 by ido09s

[SiR_RB]

It's at jez as we speak so should have results by end of week

i will keep you posted 

 

 

[R377]

Just saw this on lamspeed racing.  fully built 2.2L evo 7

6466 turbo  540kw

Edited July 1, 2017 by R377

[SiR_RB]

That's a lot of boost

[burn4005]

On 26/06/2017 at 11:22 PM, SimonR32 said:

The 6262 sillyness is never ending... New cams just got the most power and torque it's ever made

Lol what..

760 awhp on a turbo rated to 705hp.. not questioning your results but that is going to be overspeeding by like 30%

 

Very impressive that it's still happy pushed that hard. I'm interested in your exhaust back pressure and compressor outlet temp numbers.

[azzada1]

Dynapack hubber gives a possible 5-10% inflated reading.. However simons back to back results with his setup and different cam combos are awesome and the car speaks for itself performance wise.. 

Its unfortunate that the next time its dynoed it wont be a true back to back unless you can sweet talk sean and he has access to the dyno still

 

Edited July 5, 2017 by azzada1

[SimonR32]

6 hours ago, burn4005 said:

Lol what..

760 awhp on a turbo rated to 705hp.. not questioning your results but that is going to be overspeeding by like 30%

 

Very impressive that it's still happy pushed that hard. I'm interested in your exhaust back pressure and compressor outlet temp numbers.

Technically it's rear hub hp, not awhp. I don't think they have an overspeed (it's not an EFR after all)

Turning the dyno on SAE correction it shows up 797hp so god knows how much it's making at the flywheel but definitely more than the turbo is rated at. Never measured backpressure in exhaust but air temps after the intercooler are more than reasonable

[burn4005]

30 minutes ago, SimonR32 said:

Technically it's rear hub hp, not awhp. I don't think they have an overspeed (it's not an EFR after all)

Turning the dyno on SAE correction it shows up 797hp so god knows how much it's making at the flywheel but definitely more than the turbo is rated at. Never measured backpressure in exhaust but air temps after the intercooler are more than reasonable

its frustrating that no compressor maps are available for precisions because a turbo compressor power rating is usually based on an efficiency below 58% or even the stonewall flow (flow choke) of the compressor. this is the speed that part of the assembly reaches sonic speed and flow basically cannot be increased any further by spinning it faster or altering the downstream pressure. thats why the choke line is vertical in a compressor map. (although note that maps from garret state efficiency below 58% is the end of their displayed map, and they consider that point "overspeeding") It's not necessarily when it wants to fall apart, but the efficiency falls over and then finally the compressor won't flow any more due to sonic shock waves inside the compressor inlet or volute causing a choked flow condition.

its interesting that the Precisions seem to be happy well past the flow the manufacturer rates the compressor for. whereas Borg Warner made their turbines strong enough to cope with the choke speed of the compressor they paired it with and not much more as its outside the design parameters.

Edited July 5, 2017 by burn4005