N1 Turbo's Rev Range R32 Gtr

[JETGTR]

Hi Guys,

Im just wondering when in the rev range should the N1 turbo's come on boost ? standard are around 2400 ???(R32 GTR)

Cheers Paul

Edited August 1, 2009 by JETGTR

[Moodles2]

approx 3000-3500, full boost approx 3500-4500rpm.. N1 turbos have heavy steel wheels, standard R32 GTR turbos have light ceramic wheels.

[Cjmartz2k]

Really?? I get better spool than that on my 2.5L with my "laggy diesel bus turbo". That's pretty laggy.

[R31Nismoid]

totally depends on the tune and so on.

just wait till the car goes to racepace for the inspection.

[Force Fed]

Really?? I get better spool than that on my 2.5L with my "laggy diesel bus turbo". That's pretty laggy.

2.5lt of exhaust gas to one turbo as opposed to 2.6lt of exhaust gas going to 2 turbos..... you cant exactly compare that...... maybe a single on a stock 26 and see which is laggy...

[Cjmartz2k]

What? I must be missing your point here.

[Force Fed]

your not comparing apples for apples...... put 2 turbo's of the same size on a RB25 and a RB26 respectively and see which comes on sooner (with the same basis of timing and boost)

you have 2.5lt of exhaust gas flow spooling a single turbo... a RB26 with n1's is theoretically 1.3lt of exhaust gas PER turbo.... so there is NO comparison....

do you get it now that i have explained it out?

put your turbo on a RB26 and it would spool sooner then yours.... due to 2.6lt of exhaust gas flow

[Brandon]

approx 3000-3500, full boost approx 3500-4500rpm.. N1 turbos have heavy steel wheels, standard R32 GTR turbos have light ceramic wheels.

2nd that. My boost comes on around 4000-4500 and you will feel it probably around 5500... and thats untuned.

Edited August 6, 2009 by Brandon

[ali-turko]

i had 20psi by 3500-4000 there r34n1s

[Cjmartz2k]

your not comparing apples for apples...... put 2 turbo's of the same size on a RB25 and a RB26 respectively and see which comes on sooner (with the same basis of timing and boost)

you have 2.5lt of exhaust gas flow spooling a single turbo... a RB26 with n1's is theoretically 1.3lt of exhaust gas PER turbo.... so there is NO comparison....

do you get it now that i have explained it out?

put your turbo on a RB26 and it would spool sooner then yours.... due to 2.6lt of exhaust gas flow

I understood what you were saying I just didn't get your point. My point was for the hp level N1's can provide, if those spool numbers listed in the first post are correct, my turbo can provide much more hp with better spool. I was commenting on how poorly his N1's perform compared to my turbo.

Also, I think you assume to much about when what turbo(s) spools on which motor. RB25's have a higher compression ratio, a long runner intake manifold, and VCT. I'm no longer running VCT and I'm also running a short runner RB26 intake and ITB's, but I doubt you bothered to research my set up that in depth before you commented. .1L is not much in the grand scheme of things. I wouldn't be surprised at all if a 25 in stock fashion would spool those N1's quicker. I'm not saying they would for sure, but you are putting to much faith in .1L of displacement.

Edited August 6, 2009 by Cjmartz2k

[sav man]

R32/R33 N1's are laggy as hell. Our tuned Targa car is full boost at 5300rpm on R33 N1's

[gotRICE?]

I understood what you were saying I just didn't get your point. My point was for the hp level N1's can provide, if those spool numbers listed in the first post are correct, my turbo can provide much more hp with better spool. I was commenting on how poorly his N1's perform compared to my turbo.

Also, I think you assume to much about when what turbo(s) spools on which motor. RB25's have a higher compression ratio, a long runner intake manifold, and VCT. I'm no longer running VCT and I'm also running a short runner RB26 intake and ITB's, but I doubt you bothered to research my set up that in depth before you commented. .1L is not much in the grand scheme of things. I wouldn't be surprised at all if a 25 in stock fashion would spool those N1's quicker. I'm not saying they would for sure, but you are putting to much faith in .1L of displacement.

i think you really are missing the point. he just explained true fact to why his twin n1 setup spools slower than your single setup.

he isnt assuming anything at all. regardless of the motor. displacement plays a big part.

In this case, hes not putting faith in .1. Your compring twins to a single. he was not.

why do you think 10000cc v12 trucks can spool t88 size turbos and make full boost at 1000rpm? But if you then added a second turbo to that mix, the spool time would increase drematically because now the exhaust flow through the turbine has halved.

[R31Nismoid]

put your turbo on a RB26 and it would spool sooner then yours.... due to 2.6lt of exhaust gas flow

You do know its only 2555cc or there about's, RB26 isn't a true 2.6ltr.

your not comparing apples for apples...... put 2 turbo's of the same size on a RB25 and a RB26 respectively and see which comes on sooner (with the same basis of timing and boost)

you have 2.5lt of exhaust gas flow spooling a single turbo... a RB26 with n1's is theoretically 1.3lt of exhaust gas PER turbo.... so there is NO comparison....

do you get it now that i have explained it out?

put your turbo on a RB26 and it would spool sooner then yours.... due to 2.6lt of exhaust gas flow

Yes... to a point.

You also need to factor in that the exhaust housing is small, the wheels are smaller and so on to accommodate for the less of everything flowing around in a twin setup.

So whilst its only getting '1.25ltr' of flow, the turbo it is spooling is smaller...

BUT

I know Cjmartz2k is not correct to say his spools faster on the assumption it is on even field, of course it is going to be better.

Turbo is of a newer and better design, R32/R33 N1's are well known to be poor in the response market vs the power you get out of them, most reasonably well designed turbos will out perform them

[Cjmartz2k]

i think you really are missing the point. he just explained true fact to why his twin n1 setup spools slower than your single setup.

he isnt assuming anything at all. regardless of the motor. displacement plays a big part.

In this case, hes not putting faith in .1. Your compring twins to a single. he was not.

That is exactly what he is putting his faith in. He's trying to say that .1L makes the difference. He clearly said putting my turbo on the 26 would spool quicker, and putting the same twins on a 25 would not spool as quick as a 26 "due to exhaust gas flow", forgeting exhaust gas flow has just as much to do with volumetric efficiency at a certain rpm (intake, cams/VCT, compression ratio all affect that) as .1L of displacement.

why do you think 10000cc v12 trucks can spool t88 size turbos and make full boost at 1000rpm?

Because of their MUCH larger displacement, and MUCH higher compression ratios which make a LOT more exhaust gas at lower rpms. Also keep in mind most diesels only spin to around 3000 rpm, which is why it takes my 2.5L gasoline engine 3500rpm to make it spool as much, but then I still have another 4000rpm to go after that, now don't I

But if you then added a second turbo to that mix, the spool time would increase drematically because now the exhaust flow through the turbine has halved.

So wait, I just want to make sure I'm getting this right. You and Force Fed are saying twins are inherently slower spooling than a single that produces the same amount of power? Or are you simply stating two T88's would be laggy on a v12 truck?

You do know its only 2555cc or there about's, RB26 isn't a true 2.6ltr.

Yes indeed I knew that. I was actaully hoping somebody was going to argue how much that .1L did help and then point that fact out to refute them, but you stole my thunder

BUT

I know Cjmartz2k is not correct to say his spools faster on the assumption it is on even field, of course it is going to be better.

Turbo is of a newer and better design, R32/R33 N1's are well known to be poor in the response market vs the power you get out of them, most reasonably well designed turbos will out perform them

That's actaully the point of my original post. I was just trying to have a jab at how poor spooling N1's were, since a lot of people on here try and give me crap for extolling the quick spooling virtues of my turbo because (a) it's a big single and not nifty twins and (b) "old tech" journal bearing laggy diesel technology.

You did catch the crux of of my reply to Force Fed though in that you can compare the performance of the two set ups when you are comparing their spool charactaristics vs what kind of power they can make.

[GT-RZ]

your not comparing apples for apples...... put 2 turbo's of the same size on a RB25 and a RB26 respectively and see which comes on sooner (with the same basis of timing and boost)

you have 2.5lt of exhaust gas flow spooling a single turbo... a RB26 with n1's is theoretically 1.3lt of exhaust gas PER turbo.... so there is NO comparison....

do you get it now that i have explained it out?

put your turbo on a RB26 and it would spool sooner then yours.... due to 2.6lt of exhaust gas flow

I feel inclined to comment here as you have missed the most obvious point.

Clearly two turbos of equal size will spool slower than one of the same size turbo. That's not what was said. The statement was clearly made based on a judgment of his turbo making > or = potential HP and much faster spool up.

Using your theory a twin turbo setup rated @ 600hp would spool up slower than a single turbo rated @ 600hp just because the twins get less exhaust gas individually. Lets not worry about twin pulse turbines for now.

Lastly displacement plays one role of many in resulting turbo response/spool and saying a 26 will spool the same turbo quicker because of the tiny increase in displacement is foolish to say the least.

[gotRICE?]

I have been silenced.

Im staying out of this now! Clearly i havnt quite got my head around turbos yet

So please continue! Its only doing me good.

[Duncan]

not much to continue with. one of the few people with direct experience of these turbs answered your question.

R32/R33 N1's are laggy as hell. Our tuned Targa car is full boost at 5300rpm on R33 N1's

I wouldn't use N1s unless rules required me to. which they do. Full boost for me is a little sooner than Ben but I guess I run less boost

[Force Fed]

Chris (Cjmartz2k)

In relation to the spooling of the turbos -

Displacement: 2498 cc

Compression Ratio: 9.0:1

Cam duration (both sides): 240°

Camshaft Lift (both sides): 7.80

Displacement: 2568cc

Compression Ratio: 8.5:1

Cam Duration Intake: 240°

Cam Duration Exhaust: 236°

Cam Lift Intake: 8.58

Cam Lift Exhaust: 8.28

Now, it doesnt exactly show any difference but the lift difference between the 2 heads (obviously the RB25 isnt using vct) stock for stock (i havent been talking modified motors at all) will show a bit of a difference. the SCR difference would give the RB25 a earlier boost threshold yes, then take into account the single tb compared to the itb setup and its a little more apparent to reason that it would almost cancel the SCR gains that a RB25 would have.

I am not in any way saying that Twins will be anywhere near as responsive as a equivelently rated single (2 twins rated to 600hp total compared to a single for the same) but to compare a single setup on a RB25 compared to a RB26 with the N1's is a bit crazy so to speak.

I do agree with the Diesel side of things you have to say though - SCR, large capacity means no waiting around for the boost to be available.

oh and the ITB difference to a Single is rather evident if you look at the likes of a GTI-R compared to the same spec SR20DET with a single..

[NickR33]

I understood what you were saying I just didn't get your point. My point was for the hp level N1's can provide, if those spool numbers listed in the first post are correct, my turbo can provide much more hp with better spool. I was commenting on how poorly his N1's perform compared to my turbo.

Also, I think you assume to much about when what turbo(s) spools on which motor. RB25's have a higher compression ratio, a long runner intake manifold, and VCT. I'm no longer running VCT and I'm also running a short runner RB26 intake and ITB's, but I doubt you bothered to research my set up that in depth before you commented. .1L is not much in the grand scheme of things. I wouldn't be surprised at all if a 25 in stock fashion would spool those N1's quicker. I'm not saying they would for sure, but you are putting to much faith in .1L of displacement.

spot on, I would expect a standard 25 to spool up turbos much better than a 26... pretty impressive your results seeing as you have ditched the VCT and long runners on the plenum... still you have higher compression which makes a difference... why did you ditch the VCT BTW?

I didn't realise the N1's were so average... full boost over 5000 would make me cry! even the Trust 'truck turbos' on my car are all in and singing by 4400rpm... make more up top than the N1's as well... the 34 N1's seem like a much better turbo though, are they somewhat similar to the GTSS?

[Brandon]

Yea they're laggy but hey, they serve as a good platform for mods (if you're not chasing huge power). And so long as you stay in the boost range you'll be smiling endlessly.