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Always Furious. Now Fast.
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Discussion Starter #1 (Edited)
Obviously I have a problem with the fuel map. It is way too lean when the boost comes on, and then all of a sudden, right where it should start taking off, it gets REALLY (9:1 or worse) Rich and loses all power:



I am running a SDS additional injector controller with 2 720cc injectors. This pull was at like 19psi, but as soon as it got to 19, the fuel got all wacko and it stumbles and ends up down at 14psi with no power. I can't really afford to drop the ching on a VPC and S-AFC and 6 bigger stock injectors, but I am afraid that is what I am going to have to do.

For comparison, here is another NA-T dyno (look at his beautiful lack of fuel curve):



My car felt a lot stronger than the dyno showed, and the torque backed it up - I actually made 380lb/ft of torque on just about every pull. I gotta get this fuel situation figured out... I figured to be making around 400hp with the setup I have...
 
J

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Damn. Sorry to hear that Frankenstein. Although, I'm sure you'll be much happier with the VPC and bigger injectors. Plus, it'll be alot easier and safer to upgrade.

So, you're gonna use the S-AFC? Ever think about using the HKS AFR?
 

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Always Furious. Now Fast.
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447 Posts
Discussion Starter #3
I don't know if I am going to go the VPC/AFC/550cc route... That will run close to $2,000 and I am pretty much out of car money. I wonder if there is enough room in the stock injectors for me to flatten the curve just with a S-AFC?

I would need to bring the gain on the AIC up to flatten out the lean area, and then use the AFC to cut out the stock injectors at higher rpm. Might work???
 
R

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Don't feel bad, I have a VPC a GCC and the fuel curve still looks liks sh!t. It's lean at 8 PSI and beyond rich at 18 PSI (I can only read down to 10:1 on my wideband and it never went above that). I'm going to try a 6 speed VPC chip in my AT car, hopefully this will help. Unfortunately I cannot use the GCC to tune by boost level, you need an F-Con to do that and if I'm going to throw that much more $$ down I'm gonna buy a damm stand-alone system

Fuel demand is highest at peak torque, beyond that point you want it to drop off somewhat. This is exactly why I was looking at an additional injector controller that could be programmed to inject less fuel past the peak torque point when I was planning to go the NA-T route.

Good luck with your setup, you've made it this far and just need to get it tuned in to really haul ass

Rob_O
 

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Super Moderator!!ON PATROL ALL OVER!!
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talk to larry at sound performance or jarret at phr they might be able to help you out with what to do !
as fo rthe guys who went off topic ..please respect this guy hes looking for some help and your going way way off topic!
 

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Always Furious. Now Fast.
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447 Posts
Discussion Starter #6
Thanks guys.

Rob_O - did you ever find such an AIC? As we were kicking around options at the dyno, that is exactly what I was hoping existed: one that had tuneable map segments at different boost or rpm points. Do the hks or greddy ones do that?
 

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King of the NA-T's
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Hey Frank, well at least you know that there is a lot more in the car once you get the fuel tuned. What do you have the threshold and gain set at on the aic? It looks to me like you need to lower the threshold so the additionals start firing sooner, and lower the gain so they don't come on so strong. I'd guess you tried tweaking the knobs a bit and it didn't solve it? Did you try using just one of those additional injectors? Good luck man. I'm betting you'll be over 400rwhp when dialed in, just based on how the hp curve was climbing before the flood of fuel hit.

Hey, that 2nd dyno sheet is pretty nice..... :D
 

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Always Furious. Now Fast.
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447 Posts
Discussion Starter #12
Dave's dyno graph is really nice. Super flat. I think it has been tampered with ;)

I think (hope) I may have found a solution to my fuel woes:

http://www.aquamist.co.uk/cp/mf2/mf2.html#mf2

It is basically a piggyback ecu that seems to be setup to control the stock injectors in a 4cyl plus 2 additional injectors. It uses a boost/rpm fuel delivery map, but is tuneable +/- at 8 rpm points. I sent the chap off an email with a few questions, but I am optimistic that this will deal with my problems.

If it does, I will sell my SDS AIC. It probably would work fine with smaller injectors...
 

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Fuel controller

Frank

I have a Lexus '96 SC300 (same engine as the NA Supra) and have been looking into a turbo conversion. With a '96 I also have OBD II.

I spoke to Lance at Toyomoto and I visited Larry at Sound Performance. Lance is the Lexus expert, Larry is a Supra expert. They both initially suggested switching ECU's to an older OBD I ECU and then after thinking longer both said that the better way to go would be a secondary fuel controller.

Neither Lance nor Larry have a lot of experience (as of last summer) with OBD II NA conversions, most have been OBD I. After talking to both gentlemen I would suggest you call Lance as he has the most experience turbo'ing the 2JZ-GE. You might also consider a drive to Chicago, I'm sure that Larry could also fix you up.

I'm in Minneapolis and chat about your experience putting a turbo in an OBD II 2JZ-GE.

Also where did you get your work done? I've been looking for a shop in the area that knows Toyotas and is not afraid of turbos and other mod's.

Please e-mail me [email protected]

Jon
 
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