R34 N1 Trubos - how much boost

[itbmils]

OK OK - at the risk of being flamed for not using the search function, I'm going to ask how much boost

1: can I run with R34 N1 turbos (Series 1 - with the .42 comp housing)

2: should I run with R34 N1 trubos

Two VERY different questions - yes

I've just had my engine rebuild completed and run it (hurray!!). I've installed a PFC and EBC with Adj cam gears (blah blah blah – it's all just an expensive blur of spending now). Max boost is currently set to 18psi - and I'm getting ~300awkw. All in all, a good result I think.

Last time I posted this question (before I started the rebuild) - I think the consensus was that 18psi was about the peak efficiency rating for these turbos. They ?could? push more - but at my own risk.

My question is - if my next upgrade was to be ...

Bigger injectors - probably 550cc

RB25 AFMs with suction kit

Possibly a BIGGER FMIC and hard pipe kit ???

1: would that make any difference to performance @ 18psi

2: could I run higher boost - more safely and why ?

3: would cams be a better upgrade

Talk to me guys – if you have these turbos – what boost do you run and for how long have you been running it

[JH32]

I would have thought 1.2 - 1.3 bar ?

[[WLDCRD]]

JiMiH: thats roughly what 18psi is

[itbmils]

to be clear

I'm running 1.2 bar

[Guest Mashrock]

i run 1.2bar

i have what would seem to be some rather large cams..

injectors, cooler, pump.

boost from about 2.5 to 6.5k then all the way to 9000 is where it would seem the cams kick in and throw you back some more.

[pnblight]

1.dont bother with 550cc if your going to upgrade go 700cc (trust me on this one) the pfc run them like a breeze.

2.cams are a good investment when bought with adjustable wheels and the timing tuned on a dyno.(i was lucky and got over a 100rwhp increase not everyone may great such large returns, as every motors different)(have seen 30rwhp increase in just tuning std cams)

3.you will need to upgrade afms if you want to make much more power as you would be close to maxing out the std and the rb20/25 are a great choice.

as for the r34n1 turbos with .42 compressors i have yet to see a office document showing any other than .60 housing for the r34n1(gt2560r) turbos? I will try and find the threads i have seen on here with the data sheets and link to this thread.

[JH32]

']JiMiH: thats roughly what 18psi is

oh yeah sorry mate, couple of beers at work on a friday arvo generally = slowness

[itbmils]

1.dont bother with 550cc if your going to upgrade go 700cc (trust me on this one) the pfc run them like a breeze.

2.cams are a good investment when bought with adjustable wheels and the timing tuned on a dyno.(i was lucky and got over a 100rwhp increase not everyone may great such large returns, as every motors different)(have seen 30rwhp increase in just tuning std cams)

3.you will need to upgrade afms if you want to make much more power as you would be close to maxing out the std and the rb20/25 are a great choice.

as for the r34n1 turbos with .42 compressors i have yet to see a office document showing any other than .60 housing for the r34n1(gt2560r) turbos? I will try and find the threads i have seen on here with the data sheets and link to this thread.

i CAN give you part numbers if that will help

[pnblight]

i CAN give you part numbers if that will help

the only garret number i have seen 707 160-5 gt2560r

[Sydneykid]

Talk to me guys – if you have these turbos – what boost do you run and for how long have you been running it

Boost is irrelevant, it is simply a measure of resistance to flow. As you remove the restrictions, the boost goes down. Airflow makes horsepower not boost, so the aim is to have the highest airflow at the lowest boost.

I have seen them make ~300 rwkw at ~2 bar, and I have seen them make ~350 rwkw at ~1.5 bar. It all depends on how many restrictions you have removed. So forget the boost gauge and look at the inlet air temps, that will tell you when you have reached the efficiency limit of the turbos.

[itbmils]

Boost is irrelevant, it is simply a measure of resistance to flow.  As you remove the restrictions, the boost goes down.  Airflow makes horsepower not boost, so the aim is to have the highest airflow at the lowest boost.

I have seen them make ~300 rwkw at ~2 bar, and I have seen them make ~350 rwkw at ~1.5 bar.  It all depends on how many restrictions you have removed.  So forget the boost gauge and look at the inlet air temps, that will tell you when you have reached the efficiency limit of the turbos.

so what should this temp be ?

[JH32]

What sort of restrictions should one be removing ?

[itbmils]

OK

so based on the above VALUABLE input from SK - I assume if I upgrade AFMs and injectors and re-tune,

I should see the same power at lower boost

and/or

I will probably see more power @ 18psi

this assumes nothing else leaps in the way - and becomes rate determining in terms of air flow like my FMIC for example

[Cubes]

SK is talking about getting the air pass the heads in to the pots easier.

Stick bigger cams in there and you reduce the restriction, allowing greater airflow with less boost.

Upgrading AFM's to larger items will increase the turbo's efficiency. If with the N1's it makes a definite difference I'm not sure.

[Beer Baron]

i'm surprise you can make 300 all wheel killowats with standard injectors. With 253 REAR wheel killowats my standard injectors where near maxed out (granted the tune is quite rich) but still I would guess 300 all wheel killowats is around 330-350 rear wheel kws. that's quite a lot, especially with standard afms too. What is the peak voltage? and peak duty cycle??

[Sydneykid]

so what should this temp be ?

There is no absolute value, what I do is monitor the compressor outlet air temps as I increase the boost. When you go past the turbos efficiency to produce airflow you wil see a jump in the air temps, for example;

1 bar = 50 degrees

1.1 bar = 52 degrees

1.2 bar = 55 degrees

1.3 bar = 60 degrees

1.4 bar = 75 degrees

I would go back to 1.3 bar as the extra 15 degrees is going to negate any advantage power increase from the extra 0.1 bar of boost.

SK is talking about getting the air pass the heads in to the pots easier

Spot on, plus getting it out (exhaust) as well.

[itbmils]

thanks SK – it's always good to understand these things (temps)

OK - lets clear up a few details with this thread

Mazfix only have a 2 wheel dyno - so the graph I have posted is actually rwkw (not awkw) - I think SK indicated that would be more like 280awkw (we will see)

BUT

having driven the car around for a while now – it does not feel like 300kw to me (I'm no expert however)

So ..... my suspicious nature has convinced me to booked my car in for a power run on a four wheel dyno this Monday. It's the same dyno I pulled my 210awkw base line before starting my rebuild. It was a while ago – but I hope to be able to compare the tractive effort figures before and after to get a REAL comparison of how I'm looking now (weather and other conditions aside)

I've also been monitoring some of the data coming out of the PFC (as suggested) – so far I have see a peak knock of 47 (engine light came on at the top of third gear – but I did not check the injectors – sorry). How BAD is that ? (no knock is good knock - yes ?)

From what I've read on other threads – 280awkw is the peak reading I should get with the std injectors – so I doubt I'm getting that yet. Based on the seat of the pants feel (using the 210awkw as a base) I'd say I'm more in the 250-260awkw range, so I may still have some work to do. (cams you say - hmmmm)

I'll post the results of the power run tomorrow

[Guest Mashrock]

enough to break standard gearboxes,

[itbmils]

OK

had the 4 wheel power run done this morning (cold and wet here is Brisbane today) and still managed to get 291.7akwk. This is down from 304rwkw on the Maxfix 2 wheel dyno (so not that much in it really).

BUT

The guys from C&J aborted the run on the 2nd attempt due to knocking and the fact that my mixtures where leaning out (heading towards 13:1 when they stopped the run). Have a look at the attached graph of the run – and let me know if this looks like a big problem.

The first thing I notice (after the OUTSTANDING result) is the mixtures are only 12.5:1 – but climbing

The second interesting thing is that the boost level is not exactly flat, it seems to waver up and down once max boost is reached (sorry boost is not on this graph). I've just installed a PFC with the Apexi EBC and had hoped it would do a batter job than that !!!

Bigger injectors and RB25 AFMs will address this right (that's what the man said)– but what should I do in the mean time. Maxfix have offered to have another look (take out some timing I think they said). They also suggested octane booster would help (Nulon ProStrength ???)

[pnblight]

1/can i see a chart with the awkw on it?

2/afm and injectors should help BUT there maybe a problem with fuel delivery (ie pump and filter etc)

3/ are your injectors and afms maxing out on the run it's a very easy thing to see with the pfc hand controller max recall?