boosted951

I have a copy of my dyno sheet that the previous owner gave me. I have been doing some research on the A/F ratios and wanted to see how far off mine was. I do have an Apexi S-AFC II and the previous owner said he has it set where at 4000 rpm...he has it set to a maximum 50% to run rich. He said on the dyno sheet that it was running a little lean on the top end and that is why he had it running rich. I realize I do need larger fuel injectors. Maybe a FPR etc... Any advice on how to tune the afc without detonating my engine? I have not attemted to adjust the AFC just to play it safe. Any suggetstions or opinions would be appreciated.. I am running 16psi of boost with the mods listed below. Am I hurting the engine going lean at the top end? Should I not rev that high? Anyone up for a Dyno day here in Atlanta sometime soon? I realize that is the best way to tune the car...on a Dyno and with a wideband.... I do have a A/F guage, installed, but it is not hooked up....

Jeremy Himsel

You're really rich where you make peak tq, and really lean where you make peak HP. I'd be worried about the top end. There's more power to be found with some solid tuning.

boosted951

Do you think it is because of my stock injectors? Am I peaked out with the injectors on the high end? Or do you think I can tune it better using the stock injectors/fuel regulator etc...?

CPTdooberhead

you're going to want to get bigger injectors and an AFPR for that modified turbo (what kind is it exactly)- I am running 55# for my T04E, which are good enough (but would have gotten 65 if I did it again though)... be careful, that is running VERY lean at 4K...thats blown headgasket territory
-Randy

hosrom_951

I agree, you would need those bigger injectors.........

Jason_86_951

You mean very rich......

I agree, bigger injectors, adj FPR, and some dyno time should get you there.
The reason your spoolup is a bit later is because of that richness, you'll gain a bit once you get that cleaned up.
J-

hosrom_951

Your using Weltmeister chips.........try getting some proper ones (search forum on Guru and Vitesse).

Secondly, get rid of the BOV and get a Diverter Valve...........

porshhhh951

Hosrom a dyno pull is done in one gear(mostly 4th) changing from a BOV to a deverter valve wouldn't help his ar while he is in gear trying to make power.


Now is dyno's were done while you run through a couple gear's then you might have a argument.

hosrom_951

I know, i was speaking generally on the BOV vs the DV (big discussion)

They run richer, but don't think So rich to get lower than 12.0:1 or so, just a little richer.........

porshhhh951

exactly it won't really make a cause for his a/r which is what he was asking about.

I personally ran a modded stock deverter valve like a BOV at 20psi...I don't care what people say it isint a big of a deal as people make it out to be. I back fired a little sometime's and it ran slightly richer....be freggin deal

hosrom_951

" I back fired a little sometime's "

Flames must have shot out at 20psi wouldn't it be awsome to see that

porshhhh951

I have it on video in a couple of different instance's. I was running a turbo teg in one and a Supercharged Saleen mustang in another. I posted a clip of it a long time ago....do a search and see what you can come up with.

slim_boy_fat

I wouldnt say that was vey lean, about 13.5:1 is not too bad. towards the very end the injectors might be peaking out.

Never a bad thing upping the injector size...

hosrom_951

Porschhhe951: I saw it, it was during the day right?

But didn't notice the flames.........

porshhhh951

The saleen one was during the day the turbo teg was at night. If you look hard at the saleen one you can see it...and even though my friends were in the cobra behind us with the windows rolled up....if you listen carefully you can even hear it.