Dynosty Pushing the Limits... Fuel Pump and Clutch
 

Well I know our thread about where our current project car stands was a little unclear, we wanted to have a separate thread that is easily searchable down the road for owners searching to find out more information about the limitations of the stock motor/drive train. The first couple limitations we have found are the factory fuel pump and the stock clutch.

Our testing was performed on our Dyno Dynamics 2wd dyno. Our dyno normally reads roughly 10% lower than a standard DynoJet dyno.

The fuel pump we first started to notice fuel pressure dropping off around 230whp on E85 on a dyno dynamics dyno. It has been proven to be fine so far at that point and then some on 93 octane but if you are wanting to make power on E85, then we are recommending to upgrade your fuel pump. We will be pulling that out very shortly to confirm fuel pump options.

The stock clutch is the main reason we stopped pushing the car at 9lbs making 324whp, we started seeing the clutch slip on the dyno at 7200RPM. It would slip then grab then slip then grab. Our current recommendation is to upgrade your clutch if you plan to make over 300whp on a dyno dynamics dyno. We will update this thread with our take on the clutch options available to the market.

reserved for pictures and more details

The clutch slip is unsurprising, not sure what type of replacement I'll go with on this car, probably a heavy single plate, organic or hybrid disk.

hmmm...interesting info about the fuel pump. We're talking about the in-tank pump and not the HPFP right?

correct the in tank pump, the pressure at the high pressure rail was steady. But flow would not stay at a steady, we will test again post fuel pump install to confirm our prediction.

Interesting to hear fuel pressure dropping. Fuel pump install should be relatively easy? Drop the tank?

Clutch is surprising it even held 300whp at all, and even if it does, it's probably not going to hold for long with a turbo. Clutch feels weak from factory, if anything an upgraded clutch will improve feel.

According to the manual no, can be accessed from top, we will post more details next week.

Clutch is very soft feeling and probably will not hold up to a lot of abuse under 300whp but we could be wrong.

Interesting - we had rock solid fuel pressure on 10PSI .. but on pumpgas

Guess e85 is too much.

I wonder what the fuel pump looks like

Could the 850cc injectors be part of the reason the pump isn't holding up?

The genuine Walbro 255lph fuel pump is the option I hear the most for E85 builds, but options are good.

Interestingly somehow I missed the first thread. Or forgot.

This.????

Here it is:

http://www.ft86club.com/forums/showthread.php?t=14313

In

No. They are using 40%+ more fuel