For those interested in the full write up..
Swapping over to E85 wasn't just a matter of dropping in a Walbro 460 and a set of injectors for me. Last time the car was tuned was 2007 and it made 360hp at the wheels on 17psi on the PITS dyno (395hp on the 101 dyno) with the 550cc injectors maxed out. So I needed a full fuel system upgrade. I wanted to do it correctly and only once.
Engine is an FJ20 full house build by Mark Ashford.
I set it up so that I could drive to the dyno with my old fuel setup and swap everything over at the dyno and drain the tank to swap it for E85.
First things first..
I looked at all the options for external an external Fuel pump that was capable of supporting 600hp and while there are a few options that support E85, all of them were expensive and potentially had issues with over heating. I also needed a single pump otherwise a would have to upgrade my surge tank as well. In the end I decided to go with an in tank Walbro 460 as they are 100% proven and quiet.
SURGE TANK AND PUMPS
I needed to build a tank capable of housing the Wabro so I had my fuel cell design folded and welded by a fabricator without a lid from 3mm alloy.. I wanted the lid to be 5mm alloy so I could tap a decent thread into it in order to pull the lid down tight. The box is about 5L in capacity.
I also had a 50mm wide strip welded inside that was the depth of the box to mount the pump as you can see in the pics. Pump is mounted with a simple stainless saddle screwed to the plate. I also ran 50 amp wire down to the pump to account for big current draw.
The brass fittings are from a local nuts and bolts shop, I used threaded rod with a ½” hole through it and a nut on the other side with copper washers, (fuel washers don't work) and barb fittings to match the hose size. Point the barb in the right direction and lock it off.
The gasket was cut out from a sheet of cork.
The bulkhead terminals were hard to find but I eventually sourced them at EFI hardware.
The lift pump is a Holley mighty mite 35gph low pressure lift pump to replace the standard 35+ years old bluebird item. Many people seem to use an EFI lift pump but I see no use for this and is serious overkill. Sourced from VPW in Melbourne.
FUEL LINE, INJECTORS AND REG
Now the fuel line size was something I was concerned about so I measured the steel feed line to the fuel rail in order to determine the biggest restriction. The steel had been upgraded in the past and was 10mm OD but only 6mm ID. Turns out, this did not cause any kind of restriction, as most of you said on this forum.
The E85 fuel line was bought from Repco and I used ½” hose from the pump to the steel under car line and up to the rail.
Fuel reg is a SARD and I total forgot about replacing this with an E85 compliant item.. Hoping it won’t die on me.
The injectors were a big problem for me as some of you may recall from previous posts, however, after a lot of stuffing around, I ended up with a set of ID1300s. These are a fantastic injector and the engine now has better low end and idle response than the RX7 550s. Even with an ancient Wolf V4 driving them. My tuner was very happy with how nice they were to tune. Worth a mention though that they are quite a noisy injector. I thought it was tappit noise at first.
The initial tune came up ok, but we hit a huge wall with the ignition system. Anymore than 14psi of boost and it wouldn’t reach the rev limit of 8200. For each PSI of boost added, the spark would be blown out earlier in the rev range. At 22psi it would reach 6400rpm.
After looking into several options with LS1 coils etc I decided to go with an MSD 6A and Matching coil, sourced from Rocket Ind which would wire straight in to my stock dizzy.
Back to the dyno and it made another 30hp first run and gave us another 500rpm before hitting the ignition wall again. After a few runs trying to resolve this I decided to try another set of leads I had borrowed. 8.8mm Top Gun leads to replace the original 7mm factory items. The very first pull it revved another 1400rpm and made another 35hp taking it to 485. Never thought a set of leads would have made such a massive difference.
Also worth a mention, I drained the fuel after a few hundred km and found what was left was a little rusty looking. I checked the fuel filter which was clear and re drained the tank a few hundred km later and it was clean. As per the information here on the forum, E85 seems to clean the tank.
I was very happy with the end result and we didn’t bother tuning any further because the map sensor was limiting us after that. Besides, the power was certainly enough. I have run on other dynos in the past that have shown a fair bit more power so it would interesting to see if it went over 500. Anyway, street feeling is really quick. 3rd gear is useless over 4500rpm and 4th gear lets go and bounces straight to the limiter at about 6k rpm.. 5th gear hooks up though J
So to recap,
ID1300cc injectors x 4
½” fuel line to rail with 6mm smallest point in feed to rail
Holley mighty mite 35gph lift pump
40 micron sintered brass fuel filter after pump
Self made fuel box
MSD 6A and HVC coil
Top Gun 8.8mm leads
Tuned by Matty Spry at PITS
If anyone wants any more info, just let me know, hope the post wasn’t too long!