It'll be fully spooled by around 3900-4000 i bet easily once you add preload. we will find out soon.

 

Ready for a shocker? Here's tonight's run with 3 half-turns of preload vs the previous dyno I posted up with zero preload.

Attachment 333919

It made 8-9 psi more at 3900 RPM (19 psi at 3900 RPM with zero preload, 28 psi at 3900 RPM with 3 half turns)

So who still thinks the EF2.5 spools lazily? Look at that difference in torque/spool...

Zero preload @ 4078 RPM = 266 wtq
3 half turns of preload @ 4078 RPM = 326 wtq


I will test 4-6 half turns of preload and see if I can get it to spool even faster (within safety margins, of course.) But these results are even better than I expected considering 3 half turns is very light preload!

 

Also, just for ****s and giggles, here is my EF2.5 as of right now vs. my Evo 8 10.5 stock turbo via Virtual Dyno, done on the same road, same time of night:

Attachment 333918

 

32 psi at 7500 rpm??? It's pretty amazing that the turbo can do it, and I'd say that this is already a kill mode tune at least at peak rpm. Its impressive that the turbo picked up power going from 30 to 32 psi at 7500 rpm. Will be interesting to see how more whp at peak power can be had. AFRs are a bit on the scary side at peak power, and pulling them down to mid-11s would probably net about 10 whp. If timing is not optimized, there might be another 10-15 whp there as well. Overall, the peak power potential looks to be perhaps a bit more than a BBK Full.

 

I am having trouble getting the car to flow enough fuel at high RPM... modded Walbro 255. I am going to replace the fuel filter tonight, and if that doesn't work, I will drop in a fresh Walbro 255. I am really on the fence about either throwing in a Walbro 450 or getting a double pumper... I know this thing can easily do 500+ with the right fuel setup.

Also, the timing is NOT optimized for that boost level as far as I know. Tom didn't really push it at all because of the fueling issues so the timing is set rather conservatively AFAIK.

 

No way that a Walbro 255 can keep up with the fuel demand at 480 whp and 32 psi of boost with E85. Guaranteed... I've done the testing. Its not even close to being able to handle that. Don't waste your time with messing around with the fuel sock or another Walbro 255. Agree that it can be a tough choice in deciding between the Walbro 416 and a double pumper. Pros and cons to both.

 

Check your PM's.

 

agreed 100%. 480 it even has trouble and that is only possible if its modified. non modified its finished by around 420-430ish. its just forcing it to do something that it physically is not designed to do.

i think the only way a walbro 400 is good is when the feed and return are both changed -6 on both or even -8 on feed, and hardwiring the pump. then it seems to support enough for maybe 600whp dynojet or so.

not hardwired + stock lines it seems to be out of fuel by low 500whp which sucks. i just had a car last night on a walbro 400 get out of fuel by 500-520 and not hardwired + with stock lines. he has a AFPR so we could run more base fuel pressure and get more out of it, but hes going to hardwire it first. hes on a stock block, so can't take too many chances there running lean uptop.

What are you thoughts on running both 255's at once Mychailo? I have customers who do that and seem to be good to go. they just drill the siphon out like Ted B's thread explains. atleast then if one pumps dying you will see it being effected at idle and or cruise, or at least in WOT you will have 1 and a half walbro power not just 1 running once the switch fails and runs so lean you have just enough of fuel to ruin internals.

I will admit though pressure switch failures are very rare, but they do happen. its happened to me.

 

not a shocker to me i knew what it was going to do. i even told you.

glad the preload fixed it though.

 

ya already kill mode lol. now he just needs fuel to support that boost. he wont be running that anymore until we get a better fuel system in the car.

you are correct. normally richening it up will gain more power vs the afr it was at prior.

 

i wouldn't run both full time at full voltage. it will wear out both pumps faster. i really like the staged fuelling using the stock low/full voltage on the primary and a pressure switch on the second. i think the solution to pump failure or pressure switch failure is a good failsafe. tephra v7 has an option to pull boost on lean afr. makes good sense to me.

 

ya i hear you on that. running them both at the same time would seem to heat them up also side by side and make the fuel warmer also.

i completely forgot about the option in v7. i want to do that for sure. im just not sure how to get the voltage data from my aem wideband in order to do it. i guess i can set it really sensitive at first and figure the rest out from there.

that fail safe in the stock ecu is for sure badass. its to bad i did not utilize it at the time.

 

not to argue with titan's but i beg to differ with you on the limits of a 450 tom... I personally ran 596hp/525tq on VD without a hint of the pump running out of breath... thats e85 at my 3800ft elevation with a half ***'d tune from ER. Not that the tune was bad it was incomplete due to 2 previous 400s failing under e85. 2.3l, 35+ on an ef4 and 1500cc injectors... it was hardlined and is still alive and kicking running the dual voltage Mrfred mentioned currently...
it is also one of the first 450s released directly from walbro as a beta test.

in my opinion its the best option. in fact the fastest evo in town, currently on the streets that is, tuned by tom. runs it the exact same way...

 

the limits on what the pumps capable of has a great deal to do with what boost you're running and the mod list and base fuel pressure. to take full advantage though, it needs rewired + bigger feedline and return.

when its setup right it can handle a lot of power i understand that.

 

You've seen my thread on logging an LC-1 without a serial cable? That's what needs to be done. Exact same setup process as with the AEM. Just a different formula is needed.