370cc isn't enough!!
 

It sounds from waht I've read that the 370cc aren't enough injector for a v-2 with say a 3-2.87 pulley. reason I say this is even with the jwt, 370cc, and z32 maf the long term jwt guy still had to end up putting an fmu and an apexi safc on his max to make up for what jwt didn't program for, or the fact the 370cc is to small. can jwt program for this. It seems to me that its stupid to pay jwt for the ecu when your gonna end up having to just get the apex and/or fmu anyways. From what I know if you have the right injectors and a properly programmed ecu no fmu is needed.

hmm... i would think the 370cc would be enough seeing I'm running the stock with the 3.12"... I haven't used a wb O2 but my EGTs seem OK...

You can also bump the FP with the included FMU so it should be able to support a 2.87"

Are you talking about Stephen? He does not work for JWT, calling him the JWT guy is pretty lame.

Did you read his post? It was not the injectors fault.

JWT SHOULD be albe to program for it. But, EVERY car is different. JWT has a "standard" they use and not every car falls into that "standard"

At 100% Duty Cycle...NOT recommended, they are good for 384bhp(crank) assuming a "safe" BSFC=0.55 and 43.5psig.

DC=90%---345bhp
DC=80%---307bhp<~~~recommended

your correct, but during partial throttle driving, when he seems to be the leanest, the IDC is low. That's what I was reffering to. He was not maxing out his injectors, thus geting the slight pinging, during those particular conditions. So it was not the size of the injector causing that.

Know what I mean?

Or did I misunderstand your post..lol

and maybe you were not talking to me... Man I am a PW :grinno:

If the 370's are not enough, that is not JWT's fault. I'm the one who chose the injector size, and if I'm running a pulley that produces more power than the injectors can handle, I can hardly blame JWT, can I?

At any rate, that is not what is happening. I don't think you read what I said very closely. But since you missed it, I'll say it again - I did not have any problems with detonation at WOT.

I did do some tweaks to satisfy my own tuning goals, and actually I could have accomplished that by just raising the base fuel pressure a bit without resorting to an SAFC or fmu. Nevertheless, as far as I can tell, it is true that the JWT tune wasn't perfect. I think they are still figuring out how to tune the VQ engine. But it is vastly superior to controlling fuel delivery with a disk type fmu and boosting with ignition timing intended for a normally aspirated engine.

How are you tuning your car?

Bags,

You're absolutely correct. I wasn't replying to you. You posted while I was crunching some numbers on the POS computer calc. trying to answer what I thought he was asking. You answered his real question.:bowdown:

just have jwt program in a ever so slightly higher base FP bar and a richer AFR or use the fpr and turn the base up slightly, so you don't ping at partial throttle and the high end will end up with more FP so you won't lean out when your mevi kicks in or under higher boost levels....i would think...

fIrst off I didn't mean he worked for jwt, I was just to lazy to go back and get stephan maxs handle.

I am currently just using stock injectors, disk fmu-stock and 3.33 intercooled. So I am currently maxing out my injectors big time. I mean max psi for stock is 41psi at wot, so cruising down the interstate at 70-80 mph at part throttle I see that psi, when I boost the fmu takes over and I can see 65-70 psi at redline.

So I was hoping that if I dropped the bucks for a jwt they could tune the ecu for a bigger injector than 370, because it seems that they are not enough for say a 3.00 pulley. it seems to me that stephan would not have to still run an fmu to get a correct a/f ratio.

Sorry for newbie question:
But would a Walbro fuel pump increase performance (PSI) with the stock injectors?

Current setup: V-2, 3.33 pulley, disk fmu (max PSI -7.5). Want more psi without changing pulley, injectors, or adding piggyback system.
Thank you.

JWT can program for injectors larger than 370 cc/min. Or you can have them program for the 370's but with a higher base fuel pressure.

I asked ben about bumping up my base FP, and he pretty much said it would be a silly idea since my z32 maf setup would work for my HP.

I kinda wish i would have now :\

[edit]
Doh...read that wrong.
[/edit]

555cc

Or you can use an e-manage on top of the JWT ECU. You would need to set the stock injector size on the e-manage at 370cc, then calculate the new flow rate of the injector at a higher fuel pressure and set the e-manage correction for larger injectors to that. As an example 4bar (58psi) would yeild a flow rate of ~429cc and possible 446bhp, an increase of 60bhp. Dyno tuning with AFR dataloging is recomended even with this method.