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I made am extra 3kw, but how much was the fuel and how much was air temp/humidity? It is very hard to compare dyno figures at the best of times.

You won't see the knock threshold in the top end on e85, it is past the maximum torque point so it's pointless to push that much timing. As for afr's, I had mine cruising on 20:1 the other day and it just felt a bit doughy, no pinking.

This topic has been brought up many times, discussed thoroughly, and concluded by enough people who know SIGNIFICANTLY more than I do on the subject that it will make sweet f**k all difference when it comes to any risks brought on from ethanol content change and subsequent RON change.

If you are talking about a slight ethanol content change then that is closer to the truth...but your initial comment said nothing about ethanol content change...it just says that richness compensates for low octane...so again...its not right...from your words it means that I can make up by for running 91 in a 98 tuned car just by richening the mixture up...now is that right or wrong? I'll leave that to you....

 

If you are talking about a slight ethanol content change then that is closer to the truth...but your initial comment said nothing about ethanol content change...it just says that richness compensates for low octane...so again...its not right...from your words it means that I can make up by for running 91 in a 98 tuned car just by richening the mixture up...now is that right or wrong? I'll leave that to you....

 

While yes, what you've said above is exactly correct; if that's what you interpreted my post to be saying then this discussion is over as I have no time for that kind of blind stupidity.

   

While yes, what you've said above is exactly correct; if that's what you interpreted my post to be saying then this discussion is over as I have no time for that kind of blind stupidity.

Some people really don't like to be corrected....

 

Some people really don't like to be corrected....

 

Not corrected, since I know what you said was correct - I meant that what you took wasn't what I was implying (well, not exactly). Sorry for being a bit of a dick too, was grumpy as all fark that day.

Run the stock pump or better a Walbro e85 pump hard wired through a relay and fuse to the battery, fit 1000cc ev14's with the correct 10.2mm rail adapters and enlarged lower Oring, ditch the injector resistor pack and have some form of adjustable ecu.

And the critical part, find a decent tuner.

I did the swap to E85 in my GTR. The only things I changed was Sard 550 injectors to ID 1000s and Walbro 255lph pump to the E85 440lph pump or what ever it is.

Standard fuel rail is fine and I'm also running a PFC.

  • Like 1

Well I'd just built a new motor but no other power mods.

I was making 255rwkw @ 16psi on 98 previously and went up to 325rwkw @ 20psi now. It still has another 30kw or more in it with a bit of a tidy up but I'm happy with the power for now.

  • 2 weeks later...

Thanks for the link Kinks . Will read more of it later because various ethanol blends interest me though the trouble is we get what we get at the pump and DIY blending gets old quickly .

I was speaking to people on the weekend that reckon the whole flex fuel thing does not work out so well in the real world . The feeling was that the protections built into current production PCMs don't want to allow the same gains you would get from a fixed consistently blended mix . It was mentioned that some tuners don't want to remove these protections for obvious reasons and therefore you may not necessarily get the expected gains with a range of ethanol blends .

Will start a new thread in the near future , cheers A .

Finished reading that paper at last .

What I got out of it was some interesting details on fuel injection timing for direct injection (DI) and port fuel injection (PFI) .

P52 and 53 I think . I know some here have reservations about injecting fuel on the back of closed inlet valves but , it seems its not brilliant spraying onto an opening inlet valve because they open before top dead centre (BTDC) before the exhaust valves are seated so some fuel can be blown across the chambers and straight out the exhaust valves . My plug in has the timing set at 360 and I may move it around at some stage at low revs/light loads .

Around P60 they mention that it was only 97ULP and E10 that allowed detonation before best mean torque timing occured using PFI on their engine . Higher ethanol blends moved the detonation threshold beyond best torque timing .

Its around P117 118 119 and 125 they speak about what ethanol percentages the benefit levels out ie ~ 40% . They also make it clear that this is the chemical % plateau and that higher ethanol percentages may help engines where evapourative charge cooling is needed . For us I guess it means given a choice there would be some advantages to running say E40 or E50 if the state of tune is not right on the edge and you are not after every block bending Nm you can drag out of your engine .

As I mentioned in my last post E10 E70 and E85 is whats mostly available so thats what the alcos generally use . Also note that its highly probable that the 15-30% "petrol" content of E85 and E70 is pov grade ULP rather than 98PULP and even if we could get E40-50 the other part would be cheap crap too .

Anyway I'm having good times on EFlex and its not too far away . I would like to have modern injectors because its obviously critical how fast they operate and how well they spray in larger sizes . I've seen significant differences in driving charactersitics and even boost onset playing with the tunes , my engine never ever knocks even if the settings are out enough to make it drive badly . I think better injectors should make a significant difference to power drivability and consumption .

A .

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