dynotechjim
Veteran
- Joined
- May 24, 2006
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- Location
- Batavia, NY
- Website
- www.dynotechresearch.com
Today I had another TC Apex, this time a Bender/ Full Power kit that had suddenly severe reliability issues trail riding on Canadian (not that it's necessarily any worse than ours) pump gas, the owner Sudbury madman Dan brought it to Justin at Full Power an hour southwest of here, Justin addressed a bunch of issues, then insisted that he and Dan had to come to DTR to dial in for good A/F and BSFC on that sled:
Bottom line like too many others the stock fuel pump was laying down, losing fuel pressure at only 200 hp.
We jacked boost around, and made good HP but the more boost we ran on the turbo, the more the fuel pressure dropped, causing fuel flow to lean out.
Justin installed a supplemental inline EFI pump, and fuel pressure jumped 10 psi, fuel flow was now safe to 260 plus HP on Dan's canadian pump gas, 11/1 or richer A/F ratio.
This sled has 5000 km on it, and the stock fuel pump which is fine when up to snuff on brand new Apex sleds at 280hp, was now laying down losing fuel pressure at only 200 hp.
So the bottom line is here, like my experience and recommendation to MachZers on Doo Talk is that these sleds' pumps seem to be getting lazy after some miles, volume drops, pressure drops, BSFC drops and you can be bit in the testicles in an instant, especially when boosted like this one.
So Justin and others' supplemental fuel pump inline with the stock pump is a necessity to prevent age-related leanouts. I think this age related leanout happens so fast your wideband A/F guage wont pick it up. We see it instantly with the mechanical meters on the SuperFlow dyno but widebands in this situation might be too slow.
So all you boosted apex guys would be wise to fit a rail fuel pressure gauge that will tell you if your pump is getting lazy at WOT on boost, and consider the inline supplemental EFI pump that will deliver adequate fuel pressure to 400 plus hp, sold by Full Power and others. I don't know if it's the filter or the pump (you can't replace the filter only, the filter comes as an assembly with the EFI pump). But everyone will be wise to monitor this, just like the MachZ hotrodders should do.
Anyone trying to make 4 hp per cubic inch of engine displacement on piss pump gas (please read the free tech blog on my website referring to the current state of "pump" gas in U.S.) needs to make sure everything is perfect--fuel pressure is one of those things that has to be perfect.
Bottom line like too many others the stock fuel pump was laying down, losing fuel pressure at only 200 hp.
We jacked boost around, and made good HP but the more boost we ran on the turbo, the more the fuel pressure dropped, causing fuel flow to lean out.
Justin installed a supplemental inline EFI pump, and fuel pressure jumped 10 psi, fuel flow was now safe to 260 plus HP on Dan's canadian pump gas, 11/1 or richer A/F ratio.
This sled has 5000 km on it, and the stock fuel pump which is fine when up to snuff on brand new Apex sleds at 280hp, was now laying down losing fuel pressure at only 200 hp.
So the bottom line is here, like my experience and recommendation to MachZers on Doo Talk is that these sleds' pumps seem to be getting lazy after some miles, volume drops, pressure drops, BSFC drops and you can be bit in the testicles in an instant, especially when boosted like this one.
So Justin and others' supplemental fuel pump inline with the stock pump is a necessity to prevent age-related leanouts. I think this age related leanout happens so fast your wideband A/F guage wont pick it up. We see it instantly with the mechanical meters on the SuperFlow dyno but widebands in this situation might be too slow.
So all you boosted apex guys would be wise to fit a rail fuel pressure gauge that will tell you if your pump is getting lazy at WOT on boost, and consider the inline supplemental EFI pump that will deliver adequate fuel pressure to 400 plus hp, sold by Full Power and others. I don't know if it's the filter or the pump (you can't replace the filter only, the filter comes as an assembly with the EFI pump). But everyone will be wise to monitor this, just like the MachZ hotrodders should do.
Anyone trying to make 4 hp per cubic inch of engine displacement on piss pump gas (please read the free tech blog on my website referring to the current state of "pump" gas in U.S.) needs to make sure everything is perfect--fuel pressure is one of those things that has to be perfect.
sneakattak88
Expert
I went thru some old poste of yours and saw that his has happened before,, intersting,, w might be on to something here,, good thing for guys to look out for now,
snowy1
TY 4 Stroke Guru
I don,t know if the nytro pumps are doing the same thing. But I put an extra pump on mine just in case. I didn,t put it in line I have the stock pump suppling the stock injectors and the new pump and regulator suppling the mcx injectors, seems to work good. now I can adjust my a/r readings at wot with fuel pressure.I just put new suction and return lines in the tank with a seperate filter as well. so both systems are indepentant of each other.
sneakattak88
Expert
snowy funny you mention the nitro pump because some else PM me about that, he had problems,, since im not a guru like others i told him to call Justin at Full power performance,,
