Thanks guys. Think I will go CJM twin pumps, Stage 2 return and 800cc injectors. Better to be safe than sorry I suppose. I dont think I will have a hope in hell of hitting 600rwhp on my tuners Dynopack as it reads a fair bit lower than the Dynojet. Tuner says his dyno reads about 5% higher than a DynoDynamics in shootout mode.

 

The most I've heard from a single walbro was a jotech build several years ago with our stage 2 kit... It made 673rwhp I think it was on a dynojet
248c... They told me it was absolutely out of fuel and pressure was dropping on that pass.

 

In my experience, DD shootout mode reads _alot_ higher than DJ. Bone stock 2006 g35 coupe with nothing but an exhaust at the last meet did 267whp on a DD in shootout mode... a DJ would have read no more than 24x whp...DJ may have it's weaknesses, but it is at least consistent and the only dyno I would trust when comparing results between dynos.

 

cass made 640ish on a DD with single pump and meth. YOu can get a simple meth kit for 1/2 the price of a the dual pumps. The dual pumps can be added later easily if needed, so I wouldnt drop the ~1000$ (your need extra lines, fittings, electrical, etc) up front for that.

Get you tune with the RFS and injectors and see where you stand. Meth is an much cheaper option is other benefits as well.

 

A DD in shootout mode just means no corrections. In the winter it will typically read higher than a DJ (which applies negative corrections) and in the summer it will read lower (where the DJ applies positive corrections). While the contention is that DJ corrections are inaccurate, they are at least consistently inaccurate. So yes, DJ is good for comparing across to other DJ. As to which reflects true whp, there really isn't a practical way to know for any given dyno on any given day...

I have had no trouble running to near empty with the CJM stage 1 fuel system (I monitor fuel pressure inside the car). I typically fill up with a full tank somewhere in the 14-16 gallon range (needle is on "E"), same as stock.

 

I presume that was not on 93 octane nor without meth/water injection? That's really high, wow. I was talking about pump gas number though, and was just ballparking.

 

on a dyno, i bet you could get that kinda power. on the street under 'load', youd comeup short pretty quick.

also they might have tuned to AFR 12.5 which will make more power and extend fuel systems.

 

i have the aps extreme fuel system...twin pumps and plenty of fuel/bigger rails just in case u want more power in the future

 

the biggest problem with the APS "extreme" fuel system is that the injectors run out of steam early on because they over rate them. guys going for big power end up putting in some 1000cc injectors and switching to our rails because the APS rails will not fit taller injectors under the intake manifold. By then you have to redo some plumbing and get rid of their dual regulators... and by then the only thing you are still using is their twin pump, which is not as nice as ours anyway

 

i think that 550rwhp should be the most people really plan to get out of a daily driven single walbro

 

lol hahaha ok ok u got me .....well for around 650whp or below the kit works