Rb26 Turbo Comparision Graph (from Latest Hpi Mag)

[rb26s13]

yes come on im keen to seen the dyno sheet from the 2530's compared to the GTRS's on dirtgarages GTR might even help me make a turbo choice

Edited June 11, 2006 by rb26s13

[AlexCim]

ditto, wanna see what these 2530's looks like compared to GTRS's

[Swiper the Fox]

ditto, wanna see what these 2530's looks like compared to GTRS's

here's one i found but its in hp not kw..have to divide by 1.34 (i think)

[rb26s13]

my god thats a bloody impressive dyno sheet for those little 2530's : or is that the gtrs's? :

Edited June 13, 2006 by rb26s13

[sky30]

DIRTgarage:- What boost you running on that dyno run ??

[paulr33]

this is by no means a good and accurate representation. it is merely a cut and shut of the figures for reference and "ooo" purposes. i merely chopped up the twoogle graph and plotted it where i think it lays on the RB26 comparison chart. the temps, pressure etc arent the same so its not ideal. but the ramp rate is

[Swiper the Fox]

this is by no means a good and accurate representation. it is merely a cut and shut of the figures for reference and "ooo" purposes. i merely chopped up the twoogle graph and plotted it where i think it lays on the RB26 comparison chart. the temps, pressure etc arent the same so its not ideal. but the ramp rate is

its pretty close...it would be closer if you joined the "knee"(where the stock turbo arrow is pointing) of the stock graph and the knee of your curve with a straight line, as from memory they were almost equal with the stockers and walked away from them at the knee. You have them coming on way too hard with your vertical line, 2530's don't come on like that...GT-RS turbo's and big singles do though.

And yes apoligies for the "wank factor" graph but its the only one i had available to me here at home.

Note...all the Willall runs were in 2WD mode.

Edited June 13, 2006 by DiRTgarage

[mazgtr]

The boost level used with each setup is also important.

According to HPI magazine TW0-06L 442RWKW pull was at 35PSI and C16, hardly a fair comparison if the GTR's are at 20PSI and pump fuel..

[paulr33]

i cant plot data below 116km/h as i dont have any data to work with, thats why it starts mid air as the first value i have from your graph is 116km/h do you have an other dyno sheets that i can use ?

[paulr33]

but pressure is only useful for a given compressor wheel. its pointless comparing 15psi on a 2530 and 15psi on a single t04z as they both would have completely different airflow, in turn different power levels

[R31Nismoid]

The boost level used with each setup is also important.

According to HPI magazine TW0-06L 442RWKW pull was at 35PSI and C16, hardly a fair comparison if the GTR's are at 20PSI and pump fuel..

and ill say for the third time... the HPI graphs... Trust/GTRS/T04Z are just the same

No-one has been able top provide the motor spec that accompanies the turbos, so IMO all it really is achieving is a very very rough idea that i would say is not that accurate

[Swiper the Fox]

i cant plot data below 116km/h as i dont have any data to work with, thats why it starts mid air as the first value i have from your graph is 116km/h do you have an other dyno sheets that i can use ?

your in luck....here's one i dug up (literally)...its got coffe spilt on it but its still legible.

the pink line is cam timing set at zero

the red is optimum cam timing....notice the gains without comprimising bottom end power and torque

Edited June 13, 2006 by DiRTgarage

[Swiper the Fox]

The boost level used with each setup is also important.

According to HPI magazine TW0-06L 442RWKW pull was at 35PSI and C16, hardly a fair comparison if the GTR's are at 20PSI and pump fuel..

Dont believe everything you read.

I think Nismoid's comment a few posts back is one to consider. For example even on our engine...just changing the turbo's only was not a good comparison between 2530's and GT-RS's..... the cam profiles and engine capacity were a perfect match for one set-up....and a missmatch for the other. We struggled to make over 460 AWKW with the new turbo's due to missmatched components so you have to look at the entire package before turbo's are selected for each application....and more importantly budget.

Edited June 13, 2006 by DiRTgarage

[paulr33]

ok let me replot with the new data

[paulr33]

updated with new data

[Swiper the Fox]

ok let me replot with the new data

this ones in 4WD.

P.S. you have a KW graph on your website Paul....nice

[paulr33]

haha yeah i just remembed when you said that. my bad

[Swiper the Fox]

updated with new data

yeah thats about right...they were running out of puff in the top end.....on the other graph we had the bastard iced up for about an hour or two (plenum, piping, intercooler etc) and all the belts off it (it was in a dyno comp at Powercruise) to stop the top end falling over.

Edited June 13, 2006 by DiRTgarage

[Sydneykid]

updated with new data

According to that comparison Paul can make the legitimate claim that the 2530's make more power than the standard turbos EVERYWHERE. That's a true accomplishment

I have tried all sorts of turbos and I still prefer the 2530 on an RB26 everytime.

cheers

[mazgtr]

Are the 2530's still available? Or have they been dis-continued like the 2510's and 2540's?

I really must go for a ride in a GTR with 2530's, it seems everywhere i turn someone is praiseing them as the "best" turbo choice for the ultimate "allround" GTR.

When my 2540's give up the ghost ill have to look at them, or whatever replaces them.

The new GT-SS's share the same exhaust wheel as the 2530's, but a slightly smaller compressor i beleive. So faster spool up with a little less topend. I know CRD got 330AWKW from a pair so they're still very good up high.

The one thing that bothers me about the 2530's though is the very high boost levels required to achieve these kind of figures. I'd guess you would need 20PSI to get 330AWKW and 22PSI-24PSI to break 350AWKW. Thats a lot of boost for pump fuel while still retaining reliability. I wouldnt do a track day in my GTR at 20PSI and pump fuel, prolonged hard driving and warm weather would also not help.

Talking to Jim at CRD and haveing him setup up both of my cars, 18PSI is about as high as you should go on pump fuel, to still enable you to give your car a hard time out on the road and the odd track day and still have a high degree of reliability. The drag strip is a much shorter period of abuse, so higher boost is usually tolerated here.

2530's at 18PSI would struggle to top 320AWKW IMO. Still enough for the street, responsive enough for the track and powerfull enough to run 11s at the strip. Sounds like a very well rounded choice.

But if you want more than 320AWKW-330AWKW i think they start to lose their appeal as a genuine street option, as prolonged use at 20+PSI isnt going to be a very reliable option on regular pump fuel.

Thats why a turbo's performance at around 18PSI is important to me, as this is about the level a genuine street GTR is going to live at.

The 2540's fitted to my GTR by the previous owner are not a great street option. At 18PSI they make 330AWKW, but are laggy. The 2540'S strength is its ability to make big power in the 1.7-1.9BAR range, at this level 400AWKW is within reach and 10sec passes, but its hardly any use to me on the street and 99% of the time.

It just seems to me that most of the turbo options for the GTR are'nt overly practical, requireing dangerously high amounts of boost and funny fuel in order to run the turbo's in the meat of their efficinecy. Perhaps some owners have more funds or access to cheaper labour or parts than others, so can risk their engines longevity by leaning on it harder than others. Im on the other side of the fence, even one engine rebuild or turbo meltdown is almost certainly going to cost me the car, as many have stated in the past, just because you can afford to buy it doesnt mean you can afford to own it.

While running 10sec passes and makeing 440+AWKW on 2530's is achievable, its hardly practical for 99% of owners. A T88-34H will give you 400AWKW at 18PSI and the potential to run 10s, but be laggy on the treet and track. But to me, the cars that are most impressive are able to make their power or run their times as genuine "street' cars, in full street trim. Pump fuel, treaded tyres, no nitrous, exhaust with cat. These to me are the most impressive. Once this line blurrs then the car becomes a "drag" car and not a street car. To me a GTR running a 10sec pass with a big single on pump fuel is more impressive than a "drag" GTR running 9sec passes.

It would seem useing small responsive turbo's like 2530's to achieve a 10sec pass has really bridged the gap between track and strip turbo options, even if most owners will never lean on this setup anywhere near hard enough to get similar results.

Bored ramble over...

Edited June 13, 2006 by mazgtr