Rb26 Gt-rs Dyno Result

[mark99]

As the title says here is a dyno sheet for a set gt-rs's on a 2.9l gtr engine. It needs bigger injectors as you can see it hasn't fallen over yet. Will post another sheet once the bigger injectors go in.

all the usual mods have been done, including these relavant ones;

gt-rs turbos

uas extrude honed manifolds

ces race style dumps and front pipe

trust tr exhaust

hks 280 10.7 intake, 288 11.0 exhaust cams

1mm o/s intake valves

cnc ported head

cp forged pistons

eagle h beam rods

stroker crank

power fc

z 32 afms

any questions just ask.

this run is at 16 pounds, pump fuel and injectors at max duty cycle

[2rismo]

Very nice mate - well done!

[Scooby]

nice work, what sort of crank is it? RB26 rods?

[Busky2k]

Congrats. Theres definitely still more to go with bigger injectors and more boost!

Umm I just noticed that the BP on the shootout parameters is pretty damn low ie 98.8. That might be inflating the figures a bit?

[cameron]

The IT are also low, meaning the sensor wasnt in place, which will give you less power.

The hotter the IT the more power it will read due to corrections in the software.

Beside's that it looks very nice and still heading up not tappering off yet !

[fatz]

looks like i know which turbos are going on the 3.1 litre silvia

what rpm is it hitting full boost my good man

pete

[Gav]

Nice result, but as per the above posts I agree that you have more power to come as the curve is still rising.

You have a similar setup to me Gav's Dyno Graph, however note that I have shorter final gears from a GTS4, so a direct km/h comparison isn't possible.

I still have some mixed emotions over the GT-RS terbs, however it is apparent (to me at least) that to get the best from these turbs on a 2.8L you still need to get some serious airflow through the engine. Big revs, high lift/long duration cams (I'm changing my Step 2 264 IN to a 270 duration) and head porting really makes a difference.

Good luck and drop me a PM if you want to chat.

Cheers

Gav

[FATGTS-R]

Looks very good. Well done. Cant wait to see what some new injectors will do.

On the dyno parameter thing, if the IT sensor was not in place then how could it read 6 degrees under ambient? If anything shouldnt it read the same as ambient?

[T04GTR]

nice one.

another ball tearer rippin up the road

[manage13]

Mark99, What brand stroker kit is it?

[mark99]

hey guys, to answer some of the questions, its a modified rb 30 crank, eagle rb26 rods, this may sound strange but i dont even know what BP on that dyno chart means (im an engine machinist, and know very little about dyno set up), only just got the car back so not sure what rpm it hits full boost at but ill let you know.

[Munna1]

very nice

[Cubes]

Definitely an awesome result with a huge streetable power band.

Care to share how and why you modified the crank, pistons (specs rb26, rb30 or?) used etc?

[mark99]

I modified the crank, so that i could use a 26 block, instead of an rb 30 block, so that all the outside components would fit up with out modification. The pistons are a custom order, with 22mm pin, the only rod modificatonn, is re-bushing to 22mm pin

[R31Nismoid]

come on more details!

[Busky2k]

BP is the barometric pressure. The usual is around 101 or there abouts. At a lower atmospheric BP, the engine will make less power due to the decreased density of the air. So with a lower BP, Shootout mode will correct the reading (ie inflate it) to match what the engine would make at roughly 101 (or whatever the Shootout mode considers standard). So like the temperature probe, false readings can give misleading dyno results. Ie low BP = increased power just like high ITs = increased power.

Anyways nice power man, keep up the good work. Once its finalised it must be a real beast, not that it isnt now already! And yeah, more details please!

[rb26s13]

i like the sound of this.. 3litre rb26 with out having to go the inch higher block .. hmm any chance of making a little kit

also wat sort of revs are you pulling with the modified crank?

Edited June 6, 2006 by rb26s13

[Mik]

I modified the crank, so that i could use a 26 block, instead of an rb 30 block, so that all the outside components would fit up with out modification. The pistons are a custom order, with 22mm pin, the only rod modificatonn, is re-bushing to 22mm pin

Very interesting. So I assume you offset ground the crank to de stroke it a bit? Did you hardchrome it first, or are you running custom big end shells?

Was there enough meat in the ringlands to run such a low pin height (and 22mm pins)?

[mark99]

The crank is de-stroked slightly, and heavily modified, using std rb26 shells (rb30 big ends are larger than rb26). Yeah the ring lands are fine, the pin is high, but no higher than on a lot of other long stroke engies. Details on the crank mods sound vague, but i dont have exact measurments of what i did. i made templates of the shapes i made everything so i can do it again, and am in the process of figuring out if i can offer the conversion at an economical price (there are a lot of hours of labour in the modifications). To do all the mods you need a lathe, mill, crank grinder and engine balancer. But should still be able to do something vastly cheaper than japanese alternatives.

Edited June 6, 2006 by mark99

[Cubes]

Good on you Mark. Big thumbs up for your ingenuity.