Rb25 Turbos Greddy Vs Precision

[perzn_34]

Hey guys, I've done a fair bit of research but found nothing on comparing the two, Greddy/Trust vs Precision.

So i have a built rb25 with pom cams and my current setup puts out 320rwkw @ 18psi on bp98 fuel with Genuine Greddy td06sh 25g. I get full boost roughly around 4-4.2k revs and hits hard from then. For me thats a bit laggy for street use. I want similar power with much better low to mid range and more linear rather than on/off power.

I was looking into precision turbos as my bro has one on his xr6t and gets full boost from 2.8-3k and freaking 412rwkw on 18psi. PT6766… blooddy 4L fords are crazyy

Now i was looking at Precision 5858 or 5830 or even the 5557. All the billet twin ball bearing with anti surge housing. Will be low mounted with his cast manifold.

So do you guys think i will get a worthwhile improvement with any of the precision turbos over the greddy td06?? power wise and response

cheeeeeerssssss

[1400r]

running 10cm rear housing?

swapping to a 8cm will make it better on the street and super easy to do yourself and then just get a touch up tune

[perzn_34]

how do i know if mine is 8 or 10cm? without removing the turbo of the manifold? btw will e85 or flex fuel make it more responsive?

[1400r]

you have to take it off the manifold if its highmount its really not that hard way easier than spending cash on a new turbo you don't have to

the rear housing will have a 8 or a 10 on the casting were the exhaust gas enters the turbo (for lack of a better explanation)

I may even have a buyer for the 10cm rear housing for you

Edited May 9, 2014 by 1400r

[perzn_34]

Sounds good so if I get full boost around 4200 now with the 10cm, wat would I get with 8cm housing??

Also would e85 help reduce lag??

[1400r]

with my T67 10cm vs 8cm on a sr

full boost didn't really seem to change still around 4200rpm

however it drove way better off boost

[Roy]

With that sort of response on an RB25 you are running a 10cm housing. Going from a 10cm to an 8cm housing on that sized turbo will really liven it up in the mid-late 3,000rpm brand but say goodbye to having any pull over 6,250rpm.

I went from an 8cm and tried a 12cm because I couldnt get a 10cm housing and the 8cm was wild. 300rwkws and the think just blazed tyres with so much extra torque down low. Would suggest the 8cm will run better on E85 as it is too small IMO for a 2.5L engine and E85 masks such mismatches.

I ove my Trust turbos but if you want more response then time to change turbo...not pay $400 for a different turbine housing and have a compromised result

[1400r]

plenty of dudes want the 10cm though so he wouldn't be out of pocket

especially if he bought a kando 8cm

[Roy]

Its the SH 10cm though. So bigger than the T67 L2 and normal TD06 10cm housing. The L2 seems to be all the rage....they are far easier to find and the std TD06 10cm housing about the hardest to find

[Blackkers]

E85 won't give you better response; as in, it won't affect the turbo lag. You can tune to have it feel more 'gutsy' off boost if you like, just ask the tuner. Your fuel consumption will suffer though.

If you want the same top end power and better response you can use a smaller turbo increase boost. 18psi is pretty low for a built motor

OR you could go for a smaller turbo, more boost + E85 for even better response and top end.

Whatever I guess it comes down to how much time and money you want to put into it