Dyno Comparo - Various Twins Rb26

[R31Nismoid]

Ok so as promised, I have a heap of overlays. I'll explain it all as below.

Common items/points

- All cars are Racepace builds, of near similar specification. These will not alter results massively at all.

- All using stock cams (except 517z car), similar head tidy up, RB26.

- NO EBC's are being used, just the same modified actuator setup

- All cars are run on the Racepace Dyno. Calibrations are the same except one graph where the boost reading is 50% less. Explained later.

- All cars are run using the SAME set of 18's, with the SAME set of tyres on them (dyno wheels), and are all in RWD.

- All tunes are track focused, they all run a slightly safer tune than a street tune normally would.

- All cars run factory airbox, and at least 3.5" exhausts, stock exhaust manifolds, stock plenums. Most have factory dumps also

- Most cars are R33 GTR's, stock drivetrain specs. There is one R34, so obviously some difference there

Turbo Specification & other info I will just go in order, top to bottom.

Dark Blue - Custom Racepace hybrid turbo's. I will find out specs later. (It's my car)

Light Blue - Garrett -9 / boost control issues. Car has run 124mph @ Calder in this config.

Green - Garrett -5. This motor is slightly different to all the others in terms of specs (ie, better)

Red - Trust T517Z 8cm. On graph, boost is 50% less than it was. So just double it, sensor was not reading correcly. 260° 10.8mm lift cams

Pink - Garrett -7

Black - Garrett -5

Comments:

Once the -9 car's boost control is fixed, I'll get more plots.

As you can see, the -7s and -5s spool almost the same on the dyno under load, however there is a noticeable difference when on the street that is not possible to show here.

My custom turbo's however are rather crazy in terms of response, however they do fall over in upper RPM's harder than the others. I will get EVC6 just to see if there is not more that can't be done. Even 2psi extra as it falls off would make a huge difference.

About all I can think of for now. Thanks to Chris @ Racepace for spending a good 45mins today going through over 100 graphs to find the correct/final results of cars. Some cars had over 300 runs in the database, so it took a while

And Troy/(Roy) was down there hassling us to put RB20 graphs on there constantly

[N1GTR]

Good work

What about those turbos on larger motors though-did you get any 2.8 or larger graphs?

[Deano 1]

very good work, this should be sticky

[R31Nismoid]

What I'll try to do as well in the future is get some video on road in various gears with 2-3 of the cars side by side @ the same time etc.

That will further help to show the difference in response/pick-up that's hard to see on a loaded up dyno run etc.

That could be a little whole though as a couple of the cars above don't exist in those setup's anymore. Especially -5 cars, both of those now have -7s on them.

[silva33]

Thanks for putting the time and effort in Ash & Chris, I'm sure it will be appreciated by many....

[joeyjoejoejuniorshabadoo]

nice!

now put RPMGTR on there for shits and giggles

[N1GTR]

That what I was hinting at with the larger capacity bit

Do it ash

[acsplit]

Is a couple of months we should be able to add some 3ltr love

[N1GTR]

With -5's?

[R31Nismoid]

Ye, he is the mate/car i was telling you about.

I won't be putting any larger displacement though. It's just for 2.6ltr's at this stage.

What i will do though is get a mate of mine to touch the graph up in Photoshop to make the lines easier to see the lines.

My boost curve for instance gets a bit lost with the power lines

If someone could work out the RPM points @ the KM/h point, i'll add them in as well for easier reference.

[Snowman]

Not sure what the point of this thread is - but I can say my 3yo daughter drew a pretty picture like that one as well earlier today

For what it is worth the black one I think is my old 2007 Dutton set-up. Now Ash mentioned it was going to be "different" because it was in an R34 but infact that would have been from when it had the full R33 drive train in it so it really should be comparable.

Funnily enough we have noticed that there is a small drop in power on the dyno and a shift in the curve line to the right when we went from the R33 drive train to the R34 drive train on the N1 set-up. So it seems you can't ever really compare an R34 to R33/R32 graph on the same dyno exactly. (Be an interesting one to try and dig up and show one day too).

[FineLine]

I guess you must be right about real world road differences Ash, The difference between some of those is negligible considering the difference in turbo configuration. e.g. -9's and -7's etc.

[R31Nismoid]

Ah ok 33 drive - cool ill alter it then

Point, no real point i guess.

Just to see what varying setups look like @ what boost range. All the turbos are good for over 20psi without a problem on good motors, even the smaller ones even though they fall over a bit.

But ye Noel, the -9 equipped car there and another -5 car (similar spec) had rolling runs a few times and from a off-boost and the -9 car was pulling ahead in the lower gears/speeds no problems.

Id rather test that myself and video it

[JAGR33]

Nice work Ash, good to see how the various turbo setups behave on Racepace engines. The Trust turbos are the T517Z 8cm version, exactly the same as what I had back in the day. Now you can see why I went to -5's instead. The Trust turbos make good peak power but lack the low end response...

[Roy]

I love how you deleted my RB20 plot, scared that it put all your mega motors to shame!

[N1GTR]

Ye, he is the mate/car i was telling you about.

I won't be putting any larger displacement though. It's just for 2.6ltr's at this stage.

Ah right, well in that case from remembering what you said; hurry up with it!!! Lol. I'm keen to see the results from that one

I'll wait for the stroker overlay thread

[N1GTR]

I love how you deleted my RB20 plot, scared that it put all your mega motors to shame!

yeah, that must be it mate

[fatz]

ash can you add in the the detals... such as if the engines have been rebuild because there is 20-50 rwkw in a 20 year old rb26 with nasty blowby

for example one of my gtr's rb26 with -5's and 1.2 bar = 280 rwkw, blowes the dip stick out regualry so much so i run 12 pounds at the track and cable ties to hold the dip stick f**ker in

i know the same engine with a hone and new filed down rings will put out 320rwkw even with the same awesome nissan factory pistons

and 3 litres in r31's are for posers

ya fags!

[JAGR33]

ash can you add in the the detals... such as if the engines have been rebuild because there is 20-50 rwkw in a 20 year old rb26 with nasty blowby

for example one of my gtr's rb26 with -5's and 1.2 bar = 280 rwkw, blowes the dip stick out regualry so much so i run 12 pounds at the track and cable ties to hold the dip stick f**ker in

i know the same engine with a hone and new filed down rings will put out 320rwkw even with the same awesome nissan factory pistons

and 3 litres in r31's are for posers

ya fags!

All the engines above are rebuilt by Racepace.

[Count Grantleyish]

Ash, good work.

How come the one with -9s has boost control issues?

I'm curious on how -9s with boost control issue fixed would stack up compare to -7s in terms of response.