johntorg

I would like to see the AFR at around 12. Is that acceptable for a 951 turbo? It works fine on the VW 1.8T with a big turbo.

I found that the MAF clamps had been overtightened warping the end or the housing. I used a heat gun to straigten it and will epoxy it tomorrow. Where did you get the MAF? Its a Pro- Flow 85mm on the Air Cleaner side and 75 mm on the turbo side. If I can find another housing, preferably a metal one, it would be a better solution.

jimbo1111

The low is for the idle. You need to lower the fp a little. Reread my post.

johntorg

Jimbo, Sorry, I thought I read somewhere that it affects the entire range. I will turn down the fuel pressure. I am waiting for a new axle to arrive ( risked my life doing this run on a very bad CV joint)and will have to epoxy the MAF before I try again. What do you think of 12.0 as a target?

jimbo1111

It's a pro m 75mm.

special tool

I used to tell people to stay 11.8 at torque peak and let it get up to 12.5 at redline on 8 valve 951.
I now believe that 11.5 to 12.2 is better.
And I have good reason to believe this.

jimbo1111

11.8 to 12.2 a/f is very good. The motor doesn't like a lean mixture.

jimbo1111

Just when I'm starting to have fun this bum shows up. Stop beating me to the punch line damit. BTW The new cam just showed up today.

special tool

That'll get er goin good!

johntorg

At max torque, around 3550 RPM, I'm at 11.88 then The AFR drops to 11.5 until 5600 RPM where it drops a little to 11.25 but really drops to 10.5 by 6000 RPM. I wonder where the rich spike is coming from on the high end.

A.Wayne

Hello ,
You should adjust the top end mixture , it appears to be very rich above 4000 rpm
Is the A/f system you are using accurate? Have you had a chance to compare it to anything else to get a reference?


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86/ TPG 951/ 608 whp / 435 ft/tq / DTA P8

johntorg

The AFR is about 11.5 after 4000 rpm, which according to the rest of the comments isn't too bad. The real high end 6000 plus is very rich at 10.5.

Its an LM-1 and appears to be accurate. During normal driving its very close to the Tech Edge that's in the car. I'm using the LM-1, because I haven't figured out how to log with the Tech Edge. During high boost, I can't watch both displays and drive the car.

johntorg

Just posting so I can update the e-mail status on this thread

jimbo1111

Max torque on your car is 3850 rpms. To get the a/f correct you have to lower the fp and reset the low mid and high on the arc2. You have compensated as much as the arc2 will allow. Keep in mind that the chips you have are designed for stock injectors. Your injectors are 52lb. That's about 35% more fuel. The arc2 can compensate only 20%. The only way for you to reduce the fuel where you need it is through fp. It's a juggling act. If you want something more precise. See if VR can burn a chip for your maf. This is what I went to. There chip will tune your car to perfection. Without touching anything. The only reason I bother John is because I would love to know how they did it.

johntorg

Jimbo, Thanks, I saw John in Atlanta on Monday and will probably go that route. In the meantime I would like to tune the setup I have at least back to where you had it and use it for a baseline. I didn't realize that the Guru chips were set up for stock injectors. I am planning on going to 72 lb injectors when I take the next step. I also didn't realize that the clutch was stock.

jimbo1111

when I had the shop do the clutch they installed a cup disc and lightened the flywheel. The PP is stock. The PP will not hold high torque. The po of my new car installed a new clutch on my car a week before I purchased it. I am going to change it with a stage 2 Kep PP and bronze 6 puck disc. I am praying that it will not chatter.