Great post as always Mr. Fred. For some reason I always find myself subscribing to your posts!

 

I'm holding pressure across the injectors perfectly at 500 whp with ~13V to the pump, but you'll be running a fair bit more boost, so there will be less flow from the pumps. I suggest you ensure you're getting a full 14 V at the pumps. Worst case scenario is that you'll need to throw a BAP on your Evo. Also make sure the hose clamps securing the connection between the pump outlet and the nipple on the pump carrier are leak free. If you aren't already using fuel injection style hose clamps, I highly recommend them. Regular hose clamps will cut up the rubber hose.

Edit: Another thing that would help is lowering base fuel pressure to 30 psi. Might even be worth trying 25 psi. That would help make up for the insane boost I imagine you'll be running, and it will help with getting the car to idle at a reasonable afr on those injectors.

 

Will double check those connections.

Will definitely be lowing base fuel pressure. That was already in the plan. I think its gonna take about 45psi of boost to achieve this number, so with a base of 30 we should be right in the sweet spot of these pumps re: flow/pressure/

 

While we're talking about how much hp a single pump can support, can anyone tell me how MAP got 620hp outta a DW300? Doesnt seem possible.

https://www.evolutionm.net/forums/ev...rformance.html

 

If memory serves me right a 6266 or 6262 and a dynojet

 

MAP's result seems unlikely at a glance, but fuel pressure isn't logged in that chart. It is entirely possible that rail pressure is dropping, and injector duty is being increased in an attempt to compensate.

We can't say for certain one way or another about that example from where we sit, but if rail pressure drops anywhere in the power curve, the fuel pump is undersized for the job.

 

Great write up. Good for for thought.

 

I was hoping to be able to log voltage drop across the relays, but my DLPIO8 doesn't seem to have an isolated ground and fried when I connected it. I'm going to have to try to do it with my DVM.

 

Did you repin or recreate the connections to the factory relays with the 10ga wire?

 

Ted, look again at your ground. There should be a ground lead that goes directly to the batt. It was your car we tested all the wiring stuff on, and we found another .5V by direct conection of the ground to the batt. On my car, the ground has a ring terminal that goes over one of the studs for the pump assembly. There is another ground wire from the batt. that terminates into a ring term., and it goes over the same stud and then is bolted down. You should have something very similar to this.

 

My rewire utilizes aftermarket automotive-style relays and not any of the stock relays. Currently using two Durakool 40A/60A relays that are supposed to have <0.1 ohm resistance across the power contact.

Another 0.5V by direct ground to battery would not surprise me. If I start running out of fuel flow again, I'll have to try that.

 

I measured a combined voltage drop across both relays of 0.15 V at WOT max fuel flow. Pretty minimal voltage drop, so there is something else going on.

 

I wonder how much the high output alternator that R/T is workin on would help…. Instead of seeing low 13's at WOT you could see 14 or more.

 

What's your estimate on how much power the 416 will support using your entire fuel setup?

We're running it on our subaru drag car and so far we've been able to support power to trap 138(I'm estimating 600whp on our DD) this is on stock 3/8 fuel line and wired directly to the battery with a relay in between.

 

Is the car seeing 12.9V or just the pump?