Thread: SR20VE+T E85/93 Comparison (Log manifold/GT3076R/NismoTronicSA)

Distill some ethanol

That's really interesting. I'd like to try out E85 on my car because my setup is very similar, I just have a DET head. I have been scared to turn the boost up because I don't have any way to monitor knock and I don't have any experience altering timing maps. If I had E85 I just wouldn't give a shit and I'd crank the boost lol. Sounds to me like I could just leave my timing map as it is, convert to E85, turn the boost up, and gain a significant amount of horsepower.

In all honesty, I would prefer to make more power by upping the timing as compared to adding to cylinder pressure

I'm wondering as well, what the difference is in tunes. Would just changing the fuel maps/k-value and dumping E85 in make much power?

Would you also have to change the timing maps to make more power? I'm guessing you could add more timing across the map. I could increase fuel maps all day myself, but I hesitate to mess with timing maps very much.

Well what you are actually doing by increasing the timing is simply starting the ignition event sooner and there by changing when the peak cylinder pressure event occurs to be sooner. Changing the AFRs have a similar effect, albeit not nearly as accurate or direct, but changing the AFRs does speed up and slow down the flame front which changes when the peak pressure event occurs. Just some food for thought.

I only made 3 changes when going from 93 octane to E85 on this car.

I tried to keep things as close as possible without changing too much on the vehicle to do a true comparison!

1) Changed the alternate injector size to accommodate the extra fueling demands from the E85.

2) Setup the ALT maps to turn on when the input is enabled AND to use the ALT injector size

NOTE: I did NOT turn up the boost pressure, the boost controller was left at the same exact setting as it was with pump gas.





When all was said and done I did add at most 1-2 degrees to the 8-15psi columns (peak timing was actually the same above 6500!), but this is not pictured in the graphs above .. the timing was exactly the same as the pump gas tune for this comparison.

Assuming 1psi = 20whp, that's still a 40whp jump just from a different gas and a few degrees of timing. That seems almost unbelievable to me.

-G

The gains wouldn't have been quite as much if the car had a good turbo manifold on it .. the worst way to choke up an efficient engine is to put a log manifold on there.

We have seen very similar gains with high compression Honda engines (B/K/F series) when converting from pump gas to E85 with a log manifold.

We have been making 700whp + on completely stock bottom end (K20 and F20/F22C engines) with E85 and a good turbo setup. You wouldn't be able to touch that with pump gas

That's awesome good work. I wish nismotronic was obd2 compatible!

That's why we make the stepdown harness available for the OBD2 guys

But I understand the need for the factory ECU for emissions purposes .. but that is also fairly easy to put back in to get it through inspection.