E85 + Rb30det + High Comp = ?

[TiTAN]

well that's only 10% more fuel than the norm when switching to E85, but that seems a little low for so much extra timing, are you sure you aren't advancing the timing too far?

Edited January 25, 2010 by TiTAN

[fatz]

ash

ever tyred to fart with an apple in your arse

thats what a 36mm restrictors does

[Icekallt]

Here in sweden we absolutle love the E85.

As an exemple we got a friends R33 gtr making 1119 hp in the engine and 931 whp.

I´ll check what comp ratio he´s using and get back to you all. perhaps i can find how thew but the ingnition to.

[Icekallt]

but he uses an rb26 but either way i beileve that E85 wont be any problem on a rb30.

[STATUS]

i tuned a 200,000km rb30et NA single cam (9:1) with a gt30 and sc14, it made 300rwkw @ 22psi (full boost at 2000) on pulp only mod to engine was arp head studs and a 2nd hand rb26 greddy head gasket we had lying around. With E85 we would have seen mid 300's easy.

Dont be scared with the comp on E85 10:1 ftw.

[R31Nismoid]

ash

ever tyred to fart with an apple in your arse

thats what a 36mm restrictors does

It's only restricting the boost though - nothing else.

If boost was a constant (as it is in this case) then there should still be a sizeable increase.

The results i was talking about were JUST the fuel/tune changes as well. Not alterations to the amount of boost being used.

Boost was again a constant figure.

[STATUS]

Only 40hp from E85 with 15 extra degree's of timing with 40% fuel extra?

That doesn't sound right at all. Generally people are getting 35-50rwkw gains, not 15-20

theres your issue for starters (long way off), and if tuned correctley an SR20 wont like an additional 15 degrees either....

[180or200]

theres your issue for starters (long way off), and if tuned correctley an SR20 wont like an additional 15 degrees either....

How many extra degree's have you been adding over 98 with an RB? roughly?

[twinvl]

Well two points,

It was tuned to the ragged edge to begin with,

and it's an SR, so you should expect about 2/3's the gain you would see from an RB.

Also the 40% more fuel was just to be extra safe, about 0.70 lambda... The test was just to do a quick comparison before changing the turbo and putting the restrictor on so 15 degrees was probably too far, the point was it didn't ping at all and e85 is fantastic S#%& that makes high comp turbo engines very possible!

Just needs to be made more available...

[R31Nismoid]

and it's an SR, so you should expect about 2/3's the gain you would see from an RB.

[STATUS]

agreed.

[twinvl]

What do u mean , it's a SR, 4 cylinders which is 2/3 of a 6 cylinder! Same power gain per a cylinder equals 2/3 the total power gain.

[R31Nismoid]

What do u mean , it's a SR, 4 cylinders which is 2/3 of a 6 cylinder! Same power gain per a cylinder equals 2/3 the total power gain.

I knew you would say that... i just didn't want to think you would...

Friends 4G in an EVO. 240rwkw on PULP, 280rwkw E85. Same again, 30-40rwkw gains just from fuel/tune changes.

Having 2 less cyclinders is well, rather irrelevant.

That is like saying a RB20 (2ltr/6cyc) will make more power @ the same boost/fuel than a SR20 (2ltr 4cyc), and that... well... couldn't be more wrong.

[twinvl]

Yeah well an RB20 is a bit different, really comparing an SR20 to RB30 (didn't think i would need to clarify that), tho i tend to think total power comes down to bore size rather than displacment so RB25 and RB26 also compare, just the revs shift.

I just went and checked what the actual figures were (my memory it not great sometimes) and it was exactly a 25fwhp gain, but it was with a restrictor all along, and obviously not optimised on e85. The engine went on to make a further 65hp more than that by only changing the turbo, same restrictor and e85, so a 90hp gain in total just from turbo and fuel.

Unrestricted is a completly different story when you can add so much more boost on e85.

Edited January 29, 2010 by twinvl

[JonnoHR31]

tho i tend to think total power comes down to bore size rather than displacment so RB25 and RB26 also compare, just the revs shift.

dam all those people wasting their money on 30dets for no gain whatsoever

and why the hell would you wanna stroke your v8 out to 383ci, complete waste of time isnt it?

[twinvl]

I knew i'd cop it 4 that comment...

More stroke means more torque and less revs.

Take an engine and stroke it, if ports and valves are left the same and cam durations etc. are optimized before and after you will generally come out with a similar power, or at least no where near as much % power gain as % displacement increased. There's a bit more to it with manifold runner lengths and sizes, but what it comes down to is bore size, as the ultimate power limiting factors are piston speed and area for valves.

Stroking is just easier and more torque makes a more driveable engine that u don't have 2 rev as hard. I have an rb30dett for that reason, but not for outright power.

You tell me what would have more potential for power, stroking an rb26 to 3 litres or boring it to 3 litres (if possible)?

I know what I would prefer

I'm sure I've got some more comments to justify in there somewhere?

Sorry for going OT...

Edited January 30, 2010 by twinvl

[zebra]

I knew i'd cop it 4 that comment...

More stroke means more torque and less revs.

Umm....power = torque x rpm

and why to people always add timing untill it pings? 99% of engines will make peak torque and more power with less timing than what it does just before it pings.

Plus less timing = hotter exhaust gasses, which is win in a turbo car.

and NA cars will generally accellerate better with less timing as the piston isnt fighting its way up against a burning fuel mix.

im noticing a trend with E85 turbo cars in that they are a little lazier coming onto boost, which no doubt is due to the cooler nature of alcohol based fuels...then ontop the 20degs extra timing they run.

[twinvl]

Umm....power = torque x rpm

and why to people always add timing untill it pings? 99% of engines will make peak torque and more power with less timing than what it does just before it pings.

That couldn't be less true for a turbo engine, i've never seen one that runs optimum timing, even on standard boost.

Until you run on good fuel that is, then if you don't run more boost or higher comp you might as well not use the good stuff.

Edited January 31, 2010 by twinvl

[STATUS]

hmm this thread... unsubscribed.

[zebra]

hmm this thread... unsubscribed.

haha...i even unsubsribed to my own thread..still been thinking about this...i just wont have the money to be one of the first to do it