New Setup

[pnblight]

OK for one of my sheets chech

http://www.hyperdrivems.com.au/images/dyno/peterblight.jgp

I know the boost moves around a bit but theres a bit of story behind that as i was tuning at 18psi and the shop didn't have time to let me complete all what i wanted to do so we quickly adjusted the boost control to 20psi and ran it (the duty cycle was a little off) another run would have seen a flat boost curve as normal.

as for X boost at X rpm I GOT to say it one of my biggest pet hates (but i will tell you why)

As it is basically is of no real indication because boost is a measure of back pressure and a motor that builds back pressure quickly isn't necessary a responsive motor. What i work on is hp (your more importanely torque) at what rpm because that is what gets the car moving and pins you back in the seat, for example

1/ car 1 make full boost at 3500rpm and 150rwhp at this point

2/ car 2 makes full boost at 4000rpm but at 3500rpm is making 185rwhp

comparing boost to rpm you would say car 1 is more responsive but in the real world car 2 is making more hp at same rpm for less boost and will accerate quicker.

I hope that explains why.

I still believe from all my comparsions the -5 are more responsive that any of it's competitors because of the hp it will make at low to medium rpm and has the benefit of a good healthly top end.

off my last dyno sheet (not the one attached but very similar)

~135rwhp @ 3500rpm

~180rwhp @ 4000rpm

~250rwhp @ 4500rpm

~360rwhp @ 5000rpm

~440rwhp @ 5500rpm

<<<<<<<<<<<<<<

~530rwhp @ 7500rpm

Please i am not trying to get into a pissing contest either i know there are many high performing GTR out there and in no way am i try to say my is the best but simple trying to show the performance of the gt2860r 707160-5 on a mildy tuned rb26

GTR-Dad if you have any question feel free to pm me

cheers

pete

Thanks for the info Pete!

A couple things...

1 - I'd be willing to bet the reason some guys have seen no difference between rwhp and awhp is because they've used a 4 wheel dyno that connects the front and rear rollers so they roll at the same speed. Independent rollers won't work with the ATTESSA computer - it just gets confused. If the fronts and rears are rolling at the same speed the only source of slip is if the rears are losing traction on the roller. Not really a good dyno practice. The longitudinal g sensor will quite truthfully report no accelleration so ATTESSA will conclude there's no need to send torque to the fronts. They get a free ride. It still takes power to spin the front roller, but the car gets credit for doing that in the torque calcs. But it's in rear wheel drive.

2 - I too have searched hard for quantitative comparisons between the GT2860R in -5 and -7 trim. My car is a daily driver and weekend road racer so I value responsiveness highly. The math says the -7 will spool earlier and run out of breath sooner. The 300 - 325 rwkw ceiling is OK with me, so I'm planning to go with the -7 trim. I'd be happy to post boost vs rpm and dyno curves when the build is finished - maybe in late March - and would be interested to see your -5 numbers.

My setup will be:

I run a R32 GTR rb26dett

with

Garret gt2860r 707160-7

Apexi PFC and handcontrol

Manual boost control

JUN 264deg 9.7 mm lift

JUN cam wheels

???cc injector

??? afms

Apexi Power Intake

Tomei O2 housings

Turbo back 75 mm exhaust

I'll be tuned for Canadian 91 (RON+MON/2) gas and running 1.2 to 1.4 bar of boost. Should be very close to an apples and apples comparison. I've got no doubt your peak power numbers will be higher, but I'd be very interested to examine the boost vs rpm relationship below 4500 rpm.

Cheers,

Dan

[GTR-Dad]

OK for one of my sheets chech

http://www.hyperdrivems.com.au/images/dyno/peterblight.jgp

I know the boost moves around a bit but theres a bit of story behind that as i was tuning at 18psi and the shop didn't have time to let me complete all what i wanted to do so we quickly adjusted the boost control to 20psi and ran it (the duty cycle was a little off) another run would have seen a flat boost curve as normal.

as for X boost at X rpm I GOT to say it one of my biggest pet hates (but i will tell you why)

As it is basically is of no real indication because boost is a measure of back pressure and a motor that builds back pressure quickly isn't necessary a responsive motor. What i work on is hp (your more importanely torque) at what rpm because that is what gets the car moving and pins you back in the seat, for example

1/ car 1 make full boost at 3500rpm and 150rwhp at this point

2/ car 2 makes full boost at 4000rpm but at 3500rpm is making 185rwhp

comparing boost to rpm you would say car 1 is more responsive but in the real world car 2 is making more hp at same rpm for less boost and will accerate quicker.

I hope that explains why.

I still believe from all my comparsions the -5 are more responsive that any of it's competitors because of the hp it will make at low to medium rpm and has the benefit of a good healthly top end.

off my last dyno sheet (not the one attached but very similar)

~135rwhp @ 3500rpm

~180rwhp @ 4000rpm

~250rwhp @ 4500rpm

~360rwhp @ 5000rpm

~440rwhp @ 5500rpm

<<<<<<<<<<<<<<

~530rwhp @ 7500rpm

Please i am not trying to get into a pissing contest either i know there are many high performing GTR out there and in no way am i try to say my is the best but simple trying to show the performance of the gt2860r 707160-5 on a mildy tuned rb26

GTR-Dad if you have any question feel free to pm me

cheers

pete

Thanks Pete.

I agree with you completely and will PM with specifics. I can still change my turbo selection (I think) so will be very interested.

In defense of my boost vs rpm turbo performance metric, I assume identically flowing engines. I like it because I can log it without being on the dyno.

Cheers,

Dan

[gun32gtr]

Thanks Pete.

I agree with you completely and will PM with specifics. I can still change my turbo selection (I think) so will be very interested.

In defense of my boost vs rpm turbo performance metric, I assume identically flowing engines. I like it because I can log it without being on the dyno.

Cheers,

Dan

i had the same prob when picking turbos.-7 or -5 i went the -5 as for the future i would want more than 300awkw. some where round the 380 to 400awkw.. hoping the -5 are the right choice

[pnblight]

Thanks Pete.

I agree with you completely and will PM with specifics. I can still change my turbo selection (I think) so will be very interested.

In defense of my boost vs rpm turbo performance metric, I assume identically flowing engines. I like it because I can log it without being on the dyno.

Cheers,

Dan

It's a nice idea but the only problem with this is the turbos are one of the biggest facts in how the motor will flow. The other main factor is cams and especially cam timing. If you have a look at sum of my old thread you will see i once gain over a 150rwhp tuning with 1 psi of extra boost a little fuel and ignition BUT the rest ~120rwhp of the total was gain by tuning cams (exhaust especially) I do say tho that every engine is different and some gtr only gain small amounts but i have yet to see a gtr not make more hp once cam tuning was done properly.

i recommend the -5 as i have seen to many great results on them, but the -7 are a fine turbo i just dont believe there as well matched to a modded rb26(cams etc). I also had the -5 on from first mod due to turbo failure, meaning i ran -5 on a totaly stock rb26 (std everything bar exhaust, std air box,afms,injector ,ecu the lot) in this from it ran 316awhp(~360rwhp) 18psi and ran 12.0 1/4mile (1.75 60 footer). So i don't believe these turbos are to big for any level of gtr motor mods.

Pete

[gun32gtr]

yeh mate go the -5 id say ya will be happy with the descion..

[GTR-Dad]

I've changed from -7s to -5s!

Time to order quick before I change my mind again!!!

It's great to hear from guys who have actually got experience with a particular combo. My only concern was that a daily driver might not feel as snappy with -5s and with -7s. Drag racing isn't my thing and I didn't want to let the desire for big power numbers to cloud my vision.

From Pete's dyno curve (400 hp at 5500 rpm) and description of driving experience, I can see that if I'm careful with the details I'll be able to get plenty of response out of the -5s and leave plenty of room to dial things up as my appentite for power creeps up.

Cheers all!

Dan

[gun32gtr]

I've changed from -7s to -5s!

Time to order quick before I change my mind again!!!

It's great to hear from guys who have actually got experience with a particular combo. My only concern was that a daily driver might not feel as snappy with -5s and with -7s. Drag racing isn't my thing and I didn't want to let the desire for big power numbers to cloud my vision.

From Pete's dyno curve (400 hp at 5500 rpm) and description of driving experience, I can see that if I'm careful with the details I'll be able to get plenty of response out of the -5s and leave plenty of room to dial things up as my appentite for power creeps up.

Cheers all!

Dan

my thoughts also.good for minor mods and also major mods.can get nice power out of these puppies

[rawnsGTR]

Hey gun32gtr.Had the same probs as you in ordering the turbs over xmas.Got them now and went with the -5 model.Getting them put on in feb.From what I have seen on this post they are an awesome choice for the road and can make in excess of 500rwhp.Plenty for my right foot.lol.Thanks for that info on your mods and power level pnblight.It gives me a good indication of what to expect.I will let ya know how I go anyway as my setup is nearly the same as yours.Good luck bro!

[gun32gtr]

please supply pics of u standing there with a sign saying "dont u wish ur dad was rich like mine"

Hey gun32gtr.Had the same probs as you in ordering the turbs over xmas.Got them now and went with the -5 model.Getting them put on in feb.From what I have seen on this post they are an awesome choice for the road and can make in excess of 500rwhp.Plenty for my right foot.lol.Thanks for that info on your mods and power level pnblight.It gives me a good indication of what to expect.I will let ya know how I go anyway as my setup is nearly the same as yours.Good luck bro!

yeh mate never will i order over xmas again im still waiting it bullshit..yeh -5 are the go for sure.500hp at the right foot would be nice.im hoping for 440hp see how motor holds up.

just finished pulling the old ones of.thaNK god..

and yeh thanks to everyone for info

[noone]

Did U end up pulling the turbo's in car like u planned or motor out, just curious as to how much of a struggle it would be to do in car

[gun32gtr]

dude in the car is ok.just soome rachet spanners and its ok

[gun32gtr]

my new speedo gauge turned up today,just want any tips when putting it in.what to be careful of as well.also it dosnt say on the box which model its for so how will i tell if its for a 93 model etc.not for my 89-90 model..

thanks kane

[gexenon]

If its for 93 model, i take it off your hands

my new speedo gauge turned up today,just want any tips when putting it in.what to be careful of as well.also it dosnt say on the box which model its for so how will i tell if its for a 93 model etc.not for my 89-90 model..

thanks kane

[noone]

dude in the car is ok.just soome rachet spanners and its ok

cool thanks for that info and good luck with your build

[arep3]

kane if its for a model after an 89, the back will look different to the speedo that come out of ur car. easy to change parts over. any speedo for a 32 is suited, just slight modifications needed between years... PM me for more info.

[GTRsean]

Nice speedo. Damn you Kane!! it reads 20km more than mine..lol

[gun32gtr]

hehehehe yeh just started putting it in mate... good cruise yesterday aye.

you been busy posting aye sean

[GTRsean]

Yeah, as you know I'm sick atm, worse today so I'm just plonked on the computer typing away. Get around to fixing my car one day.

[gun32gtr]

yeh gee im sick of this flu it pisses me off. yeh ill get back into the speedo today sometime.maybe???

[GTRsean]

Yeah for sure. Just be careful with the plastic drive piece on the end of the cable. Those speedo drive bits are not really durable!!