N1 turbos - how much boost

[itbmils]

OK

those of you that have seen my recent posts will now that I have just rebuild the motor in my R32 GTR (should get the beast back this Friday). I have strengthened the bottom end and done a minor port and Polish (with a few other bits too) – but the major upgrade replaces the std turbos with a pair of N1s off an R34 V-SpecII

These are relatively small (street) turbos I know – but how much boost can I safely run – and where can I find some info (specs) on these turbos.

I've done a few searches – but didn't find too much

TIA

[OohArrGTR]

i just got a set good for upto 1.5 bar im pretty sure... im going to run at about 1.2 or so everyday

[itbmils]

cool - what's that in PSI ?

[OohArrGTR]

21-22 psi = 1.5 bar if im correct

17 psi =1.2 bar

something around that

[Sydneykid]

1.5 X 14.7 = 22 psi

Watch the inlet air temperatures, that will tell you when the turbos are outside the efficiency curve.

[itbmils]

My upgrade plan is as follows (in order)

Stage 1: full rebuild with forgies + the N1s – done

Stage 2: PFC + HC and dyno tune (real soon now)

Stage 3: 044 fuel pump + 700cc injectors + Splitfire coils

Stage 4: 600x300x100 FMIC + hard piping

(did I miss anything?)

I'd like to keep the boost under 20psi – just to be on the SAFE side

I'll probably do AFMs somewhere along the way too – see my post about RB25 AFMs on a GTR

The bigger FMIC will keep the temp down - yes

any guesses on a rwkw for this sort of setup

[teejay]

gotboost did 360 odd rwhp with his n1's at 17psi, its about the realistic limits of the turbines

[itbmils]

so that's about 270rwkw - at only 17psi (1.2 bar) - yes ?

what other mods did he have

I was thinking more around the 320rwkw mark myself @ ~20psi (1.4 bar)

will I need cams and pullys to get this number ?

[itbmils]

Also - what N1's did he have

My understanding is that the early N1's are NOT BB/SSteel

[teejay]

he had a 33 gtr engine, it also had mild cams in it, a ecu, i personally think 20psi is too far for them to still be in their efficiency range

[itbmils]

Well - give me 6 months or so - and I will let you know

[7heavn]

1.2bar is the most I would go, N1's perform well at that boost , At the end of the day dyno figures don't meen much it's all about power delivery and how early on your making boost which equals good times at the track .

An example of that theory would be wrxhoons's (from these forums ) r33 GTR he's running a Power FC tuned by Ben at Bel performance , n1 turbo's at 1.2bar , catback and front pipes , everything else stock even the air box and he has gone 11.7@119mph out at WSID with 60ft times that aren't all that great . The car would also perform equally well on the roundy roundy stuff as it has a usuable power delivery .

[siksII]

1.2bar is the most I would go, N1's perform well at that boost , At the end of the day dyno figures don't meen much it's all about power delivery and how early on your making boost which equals good times at the track .  

An example of that theory would be wrxhoons's (from these forums ) r33 GTR he's running a Power FC tuned by Ben at Bel performance  , n1 turbo's at 1.2bar , catback and front pipes , everything else stock even the air box and he has gone 11.7@119mph out at WSID  with 60ft times that aren't all that great .  The car would also perform equally well on the roundy roundy stuff as it has a usuable power delivery .

i know wrxhoons car as well and 1.2 bar would be the best or else very close to best (stock injectors were close to the limit)

also the best time was 11.7@121mph with stock wheels.

i am under the impression that there are a number of n1 housings which means some will be laggier than others.

all n1s have steel wheels, although only r34 have ball bearings.

[itbmils]

thanks guys - this is good info

my N1s are defiantly from an R34 - and are the Steel Wheeled BB type

AFAIK the stats for them are as follows

.64 A/R ex (I think)

76 Trim

compressor is .60

I'm not expecting much lagggggg from these

supposed to be rated at 320hp each

so does that mean 2x320 = 640hp for me

640hp = ~480kw yes ?

corrections welcome

[MADGT4]

I've SEEN figures of 5-600PS from N1's

That was in Japan however and i'm unsure what work was done to the engine

[itbmils]

how do I convert from ps to hp or kw ?

[itbmils]

i know wrxhoons car as well and 1.2 bar would be the best or else very close to best (stock injectors were close to the limit)

also the best time was 11.7@121mph with stock wheels.

i am under the impression that there are a number of n1 housings which means some will be laggier than others.

all n1s have steel wheels, although only r34 have ball bearings.

so was wxrhoons N1 SS/BB (R34s) or not ?

[7heavn]

you will have to ask him that one

[itbmils]

Well - I'm back to ....

give me 6 months and I will let you know

[MADGT4]

PS is NEAR on exactly the same as HP

So all you need to do is conver it to KW