Precision Billet Turbos

[GTScotT]

Are you willing to run the free tune offer on a stock internal 1JZ?

Do we have any guesstimates on what the unit can pump safely on 98ron and how much boost?

Am on the market at the moment but I am leaning GTX or T67... Free tuning could sway me

[XRATED]

Well sports fans.

I'll post up the dyno sheet tomorow.... However-

I ended up making 245 odd rwkw on 98 at 20psi (that drops off to 18psi at 8000rpm) from my 5557 .63 exh housing. All the usual supporting mods, no major restrictions.

I was a little dissapointed. For the lag I would have expected 255/260ish rwkw at that boost level.

It seems high boost is needed for the numbers with these turbo's. I just didn't want to run anymore boost on a stock 100k rb25.

I'll be going to a td06...

J.

[PJ.]

Well sports fans.

I'll post up the dyno sheet tomorow.... However-

I ended up making 245 odd rwkw on 98 at 20psi (that drops off to 18psi at 8000rpm) from my 5557 .63 exh housing. All the usual supporting mods, no major restrictions.

I was a little dissapointed. For the lag I would have expected 255/260ish rwkw at that boost level.

It seems high boost is needed for the numbers with these turbo's. I just didn't want to run anymore boost on a stock 100k rb25.

I'll be going to a td06...

J.

Hey Justin, what waste gate and manifold are you running?

[SimonR32]

Well sports fans.

I'll post up the dyno sheet tomorow.... However-

I ended up making 245 odd rwkw on 98 at 20psi (that drops off to 18psi at 8000rpm) from my 5557 .63 exh housing. All the usual supporting mods, no major restrictions.

I was a little dissapointed. For the lag I would have expected 255/260ish rwkw at that boost level.

It seems high boost is needed for the numbers with these turbo's. I just didn't want to run anymore boost on a stock 100k rb25.

I'll be going to a td06...

J.

Interesting... Glad I went a T67 now over one of these :-)

[Girorostar]

Well sports fans.

I'll post up the dyno sheet tomorow.... However-

I ended up making 245 odd rwkw on 98 at 20psi (that drops off to 18psi at 8000rpm) from my 5557 .63 exh housing. All the usual supporting mods, no major restrictions.

I was a little dissapointed. For the lag I would have expected 255/260ish rwkw at that boost level.

It seems high boost is needed for the numbers with these turbo's. I just didn't want to run anymore boost on a stock 100k rb25.

I'll be going to a td06...

J.

Hi Justin, quick question. At what rpm do you start seeing possitive boost?

My 5857 should arrive this week, i hope i didnt make the wrong choice.

[GeorgesR34]

Well sports fans.

I'll post up the dyno sheet tomorow.... However-

I ended up making 245 odd rwkw on 98 at 20psi (that drops off to 18psi at 8000rpm) from my 5557 .63 exh housing. All the usual supporting mods, no major restrictions.

I was a little dissapointed. For the lag I would have expected 255/260ish rwkw at that boost level.

It seems high boost is needed for the numbers with these turbo's. I just didn't want to run anymore boost on a stock 100k rb25.

I'll be going to a td06...

J.

All results mentioned are running stupid amount of boost which is impossible with stock built engines, not mentioning the amount of work done plus the juice they are drinking.

Your result would be an pretty good indication of what its capable of on a stockish motor, mild mods and more acceptable amount of boost. Any chance of showing us the dynosheet?

[R31Nismoid]

Well sports fans.

I'll post up the dyno sheet tomorow.... However-

I ended up making 245 odd rwkw on 98 at 20psi (that drops off to 18psi at 8000rpm) from my 5557 .63 exh housing. All the usual supporting mods, no major restrictions.

I was a little dissapointed. For the lag I would have expected 255/260ish rwkw at that boost level.

It seems high boost is needed for the numbers with these turbo's. I just didn't want to run anymore boost on a stock 100k rb25.

I'll be going to a td06...

J.

Sounds very similar to a HKS 2535

Interesting to see the response

[Lithium]

That was what I'd wanted to hear for ages, the PT turbos people brag about are with masses of boost and E85/whatever - I've never heard a stand out figure on pump gas. Seems that remains to be the case. Same goes for the FP HTA turbos really, I hope the new Borg Warner EFR and Garrett GTX turbos live up to their hype a bit more as most people will be running pump gas, one would assume that with the bigger advertised compressor maps they actually are able to genuinely pump more air.

[XRATED]

Here's the dyno sheet guys...

The run was on a new mainline dyno, with correct ramp and air temp correction.

The engine is a bone stock 100k km rb25 (good compression), suitable fuel system, cooler etc. It's hanging off a stock manifold with a wastegate 'adapter'- the gate is a 46mm PT gate. It's running an rb20 nistune with an rpm window switch for the vct. It has splitfire coils, ICE ignition booster and 1mm gapped plugs. Oh and a greddy copy plenum that I cleaned up and match ported.

The turbo is a 5557 with 3" inlet and 2.5" outlet comp cover... .63 ar exh housing.

The whole set up has been screwed together very well and tuned for reliability.

20psi was my boost limmit for this engine...

Cheers

Justin

Edited December 7, 2010 by XRATED

[Ryno]

I can see why you're frustrated with the result, you've got similar peak power to my GT-RS, but almost 1000 RPM laggier.

[PJ.]

All results mentioned are running stupid amount of boost which is impossible with stock built engines, not mentioning the amount of work done plus the juice they are drinking.

Your result would be an pretty good indication of what its capable of on a stockish motor, mild mods and more acceptable amount of boost. Any chance of showing us the dynosheet?

George, if you've been following this thread, you'll see that the whole 'stock' engine thing wrong, if you have access to E85 and want to go fast then you should be using it! It's the best, safest thing for us turbo heads. Pump fuel is ALWAYS going to be a limiting factor on a small engine.

If your tuner knows what he's doing you can make very good power on stock engines with good fuel. Ever seen the yellow S15 that had the number plates VOZ-000? Had a stock RB25 in it on E85 and ran low 10's, 500hp @ wheels through the auto all day on E85.

And as for the way turbo's are marketed, they are performance turbochargers after all, people put them on to go fast and use them to their potential, if that requires a higher boost level then sobeit, after all a 5557 is still a 570hp turbo!

Please don't take this personally guys, if you plan to limit yourselfs to low boost you should be running a SMALLER turbo to suit your application.

But Ryno, your GT-RS will tap out at 250kW, whereas the on his car will make 400kw! More times than not, something comes at a cost!

Edited December 7, 2010 by PJ.

[GeorgesR34]

There are plenty of cars running 98 RON fuel making more power then that with less boost. Their turbos are generally rated from 450 to 500HP. Unless this turbo can't hit its efficiency range at 20psi.

99% people has stock engines running RON fuel just like Justin. To me 500HP on 17psi with 98 is more useful then 570HP on 35psi with E85.

Keen to see other members results.

Edited December 8, 2010 by GeorgesR34

[Jpower]

There are plenty of cars running 98 RON fuel making more power then that with less boost. Their turbos are generally rated from 450 to 500HP. Unless this turbo can't hit its efficiency range at 20psi.

99% people has stock engines running RON fuel just like Justin. perhaps 500HP on 17psi with 98 is more useful then 570HP on 35psi with E85 or cocktails.

Keen to see other members results.

Why would you run low boost on a big frame turbo??? Why don't I use a sledge hammer to drive in a 8mm nail into a wall...

Physically these types of turbos are made to be wound to very high boost, usually starts to make big leaps from 25psi.

Like PJ said, if you want to run low boost then stick with smaller turbos... stop talking down the Precision turbos, or man up and wind it out to 30psi.

Edited December 8, 2010 by Jpower

[zebra]

Why would you run low boost on a big frame turbo??? Why don't I use a sledge hammer to drive in a 8mm nail into a wall...

Physically these types of turbos are made to be wound to very high boost, usually starts to make big leaps from 25psi.

Like PJ said, if you want to run low boost then stick with smaller turbos... stop talking down the Precision turbos, or man up and wind it out to 30psi.

Heat, Lots of boost means lots of heat, why have a small turbo and have to ring its neck to get the power you want, when you could run a larger turbo at less boost and less stress on everything,

I wouldve thought the 5557 would make more than 250kw at that boost.

[GeorgesR34]

20 psi isn't a little bit of boost.

I'm just speaking for and been the majority of people with whom run RON fuel with stock engines.

Edited December 8, 2010 by GeorgesR34

[PJ.]

Zebra, turbochargers are designed to work within a specific band which is boost dependent. Running a bigger turbo with less boost does not necessarily mean you will make more power on the same boost level! TRUST ME!

We run good fuel and correctly sized exhaust housings to combat heat

[zebra]

Zebra, turbochargers are designed to work within a specific band which is boost dependent. Running a bigger turbo with less boost does not necessarily mean you will make more power on the same boost level! TRUST ME!

We run good fuel and correctly sized exhaust housings to combat heat

I know that, but what I'm trying to say is: (and Im talking about street cars)

Say you wanted 280rwkws, would you use a GT-RS and run 2Bar of boost + WMI + Cams and head work, or would you run a GT3037 with a standard head and cams and 16psi?

Not everybody can afford a $5K head setup + built bottom end.

and E85 isnt availiable everywhere and I sure as hell wouldnt be buying 44Gal drums everytime I needed to fill up.

Sure if I could afford option 1 I would do it, but not everybody can or even wants to setup an engine to take big boost.

You said yourself that the SR20 went pop because of too much boost, but that was with the 6262 or what ever it was so it is understandable, but for those telling Justin to run 30psi is a bit silly for a stock Rb25.

[R31Nismoid]

But come on PJ - you have to admit at some point that a 570hp turbo on 20psi should be making significantly more than 250rwkw.

It should be around 300rwkw given a GT3076 will do those exact numbers and is similarly rated to the Precision item.

Although when you think about it, 570hp with a .63 rear housing???

End of the day, if you have to run 24-30psi, then these turbos simply are not a good choice for your average punter on a stock motor.

A built/race motor, then of course. Get the most out of the turbos and so on.

More results needed yet either way i say!

[zebra]

Also just thinking, If these turbos are not pushing much air until 25psi+, than what are they like at part throttle? or before 25psi.

Take my stock 1jz for expample, at 4psi it feels like nothing is happening because the turbos aren't pushing much air, once they build 7-8psi it really starts going because they are now coming into their effiecency range and can start pumping some meaningful air into the intake.

[PJ.]

20psi is on the higher end of the boost region for a Nissan running standard comp, but is by no means high boost for the turbo's that people have traditionally run such as T78's, T88's, T04Z's, GT35's, even 3076R's.

Times have changed guys, we have better turbo's, better fuel and greater tuning knowledge. If you're happy to stick with 98 and 98 only, then you probably shouldn't be using anything over a turbo rated to 450hp-500hp