Track used supercharged z4m cooling questions? (E85 fuel?)

[Calichase]

Hey guys,

After installing my vf570 kit and getting ttfs to tune it, I'm breaking the car in with the new rod bearings and vanos upgrades.


I have relocated to central Florida and am preparing the car for Sebring, Daytona, and Homestead.

I have been worried about heat soak with the kit and planned to do the following

-zionsville larger radiator
-setrab 34 row oil cooler (mounted on passenger side oem brake duct well)
-frozen boost larger heat exchanger
-aquamist meth kit (1 in each runner and 1 in the blower entry) with windshield washer fluid primary tank and trunk mounted excess reservoir (both baffled). Have a fail safe built in to open bypass valve in meth lines do not provide fluid into ports(meth programmed with tune to spray linear as rpm raises)

So after relocating, I realized that my local gas station has e85 for $1.75/gal (vs 93 at $2.50/gal).

I have always been hesitant with e85 in the z4 as I felt it restricted the cars use.

I know the basics of its use, like ~30% less lower heating value requiring more physical fuel to be burned. That and the higher octane rating means it burns cooler.

So in short on a z4m, you probably need to upgrade the fuel pump and lines to be able to take the high ethanol content without degrading parts and get a tune to advance timing further to get more power (if need be)

By doing the cooling upgrades and using meth with 93, this would mean on the track I'm meth dependent which isn't really a good thing. And 2 gals of meth goes a lot faster then 13.5 gals of e85, and meth is definitely more expensive.

I talked with Frank Smith way back and he does e85 conversions for the f/I e46 m3 that are pretty sweet. Essentially Just a new filler neck line I believe and then a retune. But, the mss54 can hold a couple tunes and has the capability to bounce back and fourth. Therefore if you don't have e85 available, you can swap tunes and go with 93.

Well ofcourse the terrible mss70 can't to that. It's either always 93 or always e85 (but an axillary unit like a Advanced fuel dynamics's controller could be used.)

On a forced injection car, e85 benefits are insane. Not even considering the power benefits from advancing timing due to further knock reduction, and ability to run a ton more boost (25% more at a minimum), the lower combustion temperature is awesome for a track car. Meaning for the same power levels the car is running a ton cooler.

Fuel economy wise the 30% loss in mpg is basically eaten up by the cheaper cost. I would have to come to the track with a couple gas cans as I doubt I can find it nearby, but I do that anyway because of how expensive track gas is.

I never wanted to do e85, but with its availability to me, and track benefits I'm reconsidering it rather then doing a complicated meth kit.

Lastly meth injection with e85 is not really helpful as the cooling effect and octant boost is minimal.


Thoughts?

[GuidoK]

To what timing (deg. before tdc) are you planning to go?!?

Usually if you want to profit from higher octane you go for more boost.
More advanced timing will exponentially increase the forces on your rodbearings, conrods and crank. You do realise that dont you?

[Calichase]

To be honest I don't Intend to actually advance timing. It's more just running the current 93 tune specs safer and cooler. Yes it does give me the ability to increase power but cooling is what I'm after.

[dre99gsx]

On my 2JZ4, I'm running 50/50 meth-water as my "cooling agent". In the 2J world, our motors can run 700-800whp no sweat for extended periods on straight 93, but you're mostly talking 1/4mile or highway pulls. Extended racing is another ballgame...

I converted my Supra to E85, and there is a large hassle factor - finding the fuel, having to fill up more often, and maintenance (can't let it sit too long without running 93 through the system, checking pump/lines often, etc).

I've stuck to 93 on the Z4 and water/meth for that factor. Meth is a lot more resilient than you think! I run the AEM 1 gal tank in the rear and the 1000cc injector (for perspective, I run two 1000cc injectors my Supra which is pushing out near 900whp on pump, which I've also run and used at Pocono raceway North course a few times!)

I've run 3 sessions at Pocono in various configurations with the 2JZ4, one of them a long IMSA course reaching over 160mph on the long straights. A full 25 minute session would run me about 1/2 gallon of water/meth. I mix Windshield washer fluid and 4 HEET bottles to get 50/50 - $1.60 per bottle, $1 for washer fluid = $8.00 rounded up Windshield wash fluid already contains 33% meth. I also run through 1/3 tank of gas (running 22lbs of boost consumes lots of fuel!). The Z's small tank may force you to have to fill up before every session Especially if you are concerned of high corner-gs with a nearly-empty tank.

It isn't as expensive as you think, comparatively speaking. But, you get some great cooling benefits and additional safety factor built in. I also run only one nozzle pre-throttle body. How do I know the meth is working? My knock is well under thresholds during the entire two day HPDE session.

Hopefully that provides some perspective.