Joe at cms got my fg f6 to run 500rwkw on 1000cc injectors e85 and that's on kpms 1000hp drop in fuel system. Not sure how different the territory's are but just thought id chime in Joes great guy btw

Motors pulled down Iv got 040" to 0 deck it and that's after taking 010" off already and Ill chase up to find out whats safe to take off the head. 2200km in and still at 153 to 155psi?? that could be part of the problem for being lagy. The original engine with over 200k had 173 to 185psi. All valves are sealing 100% but haven't lost even 1/2 a thou off the rings. 1 piston has gotten caught which caused a very light knock but still had 155psi.. Reason for getting caught is anyone's guess. Spent half the day checking bore to piston clearance and all are 100%. Back together she goes tomorrow and this time close up the ring gap even more. Anyone know what their comp reading are?

If your going to run E85 crank the compression up.

Yeah I think the forged Mahles were a bad choice, too much of a dish.

Arron, Would you mind explaining how running E85 allows you to run a higher cylinder compression? Is it because it's less dense? And that's not something that's always done by tuners when they tune the car for E85 is it? (if it was I guess that would explain why people get such astonishing results with it).

Higher octane of E85 ("105" but it varies) and its ability to cool the intake charge allow it to resist detonation (pinging) better than standard petroleum fuels which is why turbo engines generally run lower compression to allow a safety margin for the tune.

If you increase the compression, the engine will run better (make more power) on and off boost, the tradeoff being a tighter detonation window to tune with. Equally, you'll be more susceptible to issues with E70 winter blends as the detonation resistance drops with less alcohol content.

People don't normally increase their CR unless they are doing a full rebuild and replace the pistons / use an N/A motor. Generally they just get it tuned at the standard CR. Why they make gains is the ability to increase the timing while resisting detonation.

Hope that helps?

Edited August 19, 201511 yr by huggy_b

Higher octane of E85 ("105" but it varies) and its ability to cool the intake charge allow it to resist detonation (pinging) better than standard petroleum fuels which is why turbo engines generally run lower compression to allow a safety margin for the tune.

If you increase the compression, the engine will run better (make more power) on and off boost, the tradeoff being a tighter detonation window to tune with. Equally, you'll be more susceptible to issues with E70 winter blends as the detonation resistance drops with less alcohol content.

People don't normally increase their CR unless they are doing a full rebuild and replace the pistons / use an N/A motor. Generally they just get it tuned at the standard CR. Why they make gains is the ability to increase the timing while resisting detonation.

Hope that helps?

Hi Mate,

Appreciate the response I was aware of most of that, but unless I didn't quite understand it all correctly I still haven't quite got why you can run higher compression on E85. Arron said if running E85 the OP should crank up the compression. I have made the assumption that he is encouraging that purely because of the E85, meaning that it is more forgiving and safer to run higher Compression on E85 than pump fuel (95/98 etc). Firstly, is that correct?

I'm aware that running higher compression can increase power and naturally aspirated cars generally have a higher compression ratio as oppose to vehicles with forced induction. Are you saying that E85's ability to cool the intake charge and resist detonation allows there to be a bigger margin for safety in the tune, therefore allowing the possibility of upping the compression (closing that safety gap) that would not be possible in something running on petroleum (because of it's smaller window of safety)?

Thanks again

Yes

Ok haha, cheers.

Do you guys think going to a 13cc dish from a 15cc will bring the comp up to the low 9s?