Are you running flex fuel pat?

No, E85 only. With lots of boost it runs like crap on pump gas to get it to not knock, so E85 only.

Might help with winter blends though.

Yeah I googled it a while back and legally, E85 can go down to E51 I think it was.... Though in TX the sticker on the pump is E70 min where I buy fuel, thus I assume that's the minimum I'll get.

EGO is setup and working.

Like I said, new to E85, so taking things slow and learning. Thanks for the advice everyone, I do appreciate it.

In for supercharged ALLOFIT :party:

It will be ALL of it, I promise. Maybe more. ;)

Implementing flex fuel is still a very good idea for a car that will be using pump E85 that can change without notice. Having the ECU be able to make adjustments for even the differences between E70 and E85 is definitely a good thing. Not to mention there's always a chance of getting a really low concentration batch. People/gas stations make mistakes.

Its relatively cheap with an MS3. I bet you could get it done for less than ~100. And it works well from what I've heard from @yank. I plan on implementing it soonish.

Sorry this took forever, but here's a VD finally.

AFRs are plotted in the VD, but they varied from 11.0 to 12.0 between the various runs as I got the fuel dialed in from 11.0 to 12.0. VD seems to vary enough run to run that it didn't really show much difference. In the 1/8 mile, I gained a few MPH going from 11.0 to 12.0 AFRs though, so I know it helps. I got a feeling I need to add timing now. At 10.5-11.0 AFRs, the plugs and knock sensor both showed knock with any more timing than I have it running now. I suspect it will take more timing now, will test in the near future. Only 18 degrees at 7,000 right now...

Fuel on this log is at 85% duty cycle at 7,700 RPMs.

Attachment 183842

Attachment 183843

Vid at the track, had a boost leak so only 17 PSI but it's something.


Thoughts? I think it should be making more power.

It's timing related for sure, though there could also be something else that's a bottle neck too.

I swapped pulleys and got the boost up to 26 PSI at 6,900 now.

Then I started messing with the timing a bit, and adding 1.5* of timing at 5,000 RPMs showed a 30 ft*lb gain in torque. :idea: Pretty safe to say I'm not a MBT yet. I'll throw some new plugs in it and try to get the timing dialed in next.

Oh yeah, 259 ft*lbs of torque at 4,800 :party:

IF it likes the timing, keep feeding it in. I'd agree you definitely should make more power.
More boost + less revs IMO is another thing to keep in mind to keep those idc's in check

Yeah with the smaller pulley I get more boost and less revs, so I think that's good for engine reliability and idc's.

The problem is the oil case is running 160*F hotter than ambient with this 2.59:1 pulley, vs 100*F over ambient with the 2:1 pulley. I'm going to try removing some of the oil from the oil case and retesting to see if less oil drops the oil case temps. That's about the only thing I haven't tried that might help.

If I can get the SC happy, then I'll plan to keep the pulley for now and get back to working on the timing. The car is silly in 1st/2nd with this pulley and sticky tires.

Why would dumping the same heat energy into a smaller quantity of case oil result in lower case oil temps?

oil case as in supercharger itself?
perhaps oil cooler like the brotrex is in order?

This geartrain is splash lubricated. At low RPM, you need a high oil level to ensure adequate lubrication. At high RPM, that extra oil is just getting pumped around and heated up with no benefit.

For reference, I found a document from KenneBell (I have a whipple though) and they require (not recommend) dropping a 1/4 to 3/8" off the oil level for high boost/race applications to lower oil case temps. Whipple does not, but I think they should and thus plan to test this.

Yes, oil case of the supercharger where the gears are. I could do an oil cooler, but it would be very expensive to do. Minimum I'd need some fittings, hose, heat exchanger, pump, and oil. The oil the Whipple takes cost 26 dollars/4 oz = 208 dollars/qt.

shouldn't revving to 7 vs 8 help alleviate much of the extra heat?

The SC gets the hottest while at sustained highway cruise. At 3,100 RPMs, the oil case is 100*F over ambient with the 2:1 pulley, 150-160*F over ambient with the 2.59:1 pulley. Sustained highway speeds get the SC the hottest as it's spinning fast, but very little mass flow of air is going through it to cool it. When you open the throttle, it sucks in tons of cool air and temps drop.

I only dropped the redline of the motor to 6,900 because the new pulley ration puts the SC at 18,000, it's max continuous RPM rating with the 2.59 pulley. The 2:1 pulley would let me rev to 9,000 before hitting the 18,000 limit.

So what is it about superchargers that requires super expensive, unobatanium oil?

--Ian

Im guessing cause they don't cool it, just sits there and bakes

Regarding the twin screw, the oil has to hold up at really high temperatures with not a lot of cooling. My SC is sending about 100hp through the gears with an oil capacity of 5.5 oz. And it's designed to have a 100k mile oil change interval.

Also, I dropped the oil level 1/4", the oil temp delta-T over ambient dropped a solid 20*F. The compressor was actually 40*F hotter on the second test, yet oil temps were STILL 20*F lower. So less oil definitely helped. Had the compressor been the same temp as before, the oil case delta-T would have likely been even better.

EDIT: Oh yeah, 267 ft*lbs at 4,200 RPMs now. :)