dyno appointment time

[slider_buck]

cool, i guess cardomain doesn't care. heres the other one

[5150 LX]

hmmm worked there for a few for me, lol

[slider_buck]

it just showed up as a red X. geocities even says something no diect linking when you setup a webpage through them, kinda sucks. i need to just buy me some web space somewhere so that i can post up videos.

where do your guys usually have you a/f ratio at after getting dynoed? i saw ones guys dyno sheet and his was around 12-13 range. the guy that dynoed mine said that they always like to run them below 12:1. anyone have any dyno sheets of of 302 around my horsepower?

[regattacoupe]

mine is in photo post i believe.

[fanglemeister]

Hey Todd,

I have a few questions about your dyno romp: was this a chip tuning session or a run what ya brung deal with some minor traditional fuel & spark tweeking between pulls?

If I am correct in assuming that you are not running an FMU, but relying on the MAF and 36# injectors with the oem eec calibration... If so, your inconsistent up-down a/f ratio seems a little odd; you ought to look into that a bit further - you might be blowing out your spark as you cross over your torque peak, letting some raw fuel blow out the pipes due to partial misfires. The jaggedness in the power curve at the top end might also indicate some misfiring. A stock computer should hit a fairly consistent 11.8:1 at WOT, with a good MAF calibration and proper fuel pressure.

If this was a chip tuning session, I'm curious if the tuner actually intended your a/f to dip into the mid 10:1 range to keep it from pinging above 4k rpm. I would think for best results you should be targeting a more consistent a/f ratio between your torque and hp peaks, the only guys I know who actually need that much fuel are running alot more boost, over 20 psi. {edit - you should be targeting mid 11:1, just like the dyno guy indicated}

FWIW, using the eec-tuner and a 75mm Pro-M bullet, and a wideband, many people, myself included find that they need to lean out the bottom end an average of 12% to 15% and the top end about 5% to 8% when running a Bullet meter. And the blower cal Pro-Ms are much worse than that, let's not even go there.

Regarding timing, if running the oem calibration with initial set to 10, you are running 26 degrees total at WOT; might want to back that down just a hair, would probably help smooth out that jaggedness in the top end of the curve - or simply go with water injection and don't worry be happy, run 12 initial 28 total, and get that +35hp you feel you might be missing, and be safer.

[slider_buck]

he burned a chip for me. he was having problems with some knock up top and had to back the timing back a bit. i forgot to ask him what the total timing was also. i'm going to call him monday and find that out. and your correct i'm not using an fmu which caused a probelm initially but we turned the fuel pressure up 10 and got out of that. it is now 48 with vaccum off. i hope im not blowing the spark out but you never know i guess. i have the plugs gappesd at 35 and i have an msd ignition on it. what gap do you guys usually run? also the pro-m that i got was calibrated for a supercharger. how exactly does water injection work? is something like nitrous that is only one when you want it to be?

[fanglemeister]

he burned a chip for me. he was having problems with some knock up top and had to back the timing back a bit.

I figured as much with your high static CR. <grin>

i forgot to ask him what the total timing was also. i'm going to call him monday and find that out. and your correct i'm not using an fmu which caused a probelm initially but we turned the fuel pressure up 10 and got out of that. it is now 48 with vaccum off. i hope im not blowing the spark out but you never know i guess. i have the plugs gappesd at 35 and i have an msd ignition on it. what gap do you guys usually run?

Your a/f curve starts out on the lean side when you first get on it, which is normal actually, and can be tuned out on the chip given enough tune time, but then it dips way down into the tens, which is probably a function of your having a blower calibrated Pro-M, which is setup about +15% rich depending on your intake configuration. Figure the eec is targeting 11.8 and the Pro-M is adding +15% fuel, 11.8 - 15% = 10.03:1. Power-wise that is a hair too much for 10 psi boost, but your dyno guy is keeping it safe for you. Keep in mind as your O2 sensors learn about the higher pressure and start compensating during closed loop, over time it will start trimming fuel across every mode of operation including eventually, open loop WOT. The only way to keep this from happening is to have the chip programming setup to indicate larger than 36# injectors, whatever your injectors flow at 48 psi should be entered as the injector slope in the programming.

also the pro-m that i got was calibrated for a supercharger. how exactly does water injection work? is something like nitrous that is only one when you want it to be?

Ugh, those blower cals are just a bandaid, a ham-fisted method of adding fuel for those who can't get proper eec programming done. Typically, a good chipper will enter the exact MAF transfer curve and injector sizes; the only good reason to bump up your fuel pressure is if you are actually running out of injector at the top end, which I doubt is happening at 400-425 hp. And as I said, you really need to calculate what size your injectors are emulating at the higher pressure and enter that data in the programming for a good long-term solution that the eec won't learn around.

Regarding the water injection, it is just like nitrous, you can use either a WOT switch or a boost sensing switch, the better $ystems shoot proportionally to the boost. It's a method of cooling the intake charge and also buffering detonation in the combustion chamber. You can run a 50/50 mix with methanol (alky=120 octane) for even better performance, although water alone isn't bad.

Snow Performance has a decent setup:
http://www.snowperformance.net/default.htm
It runs about $300 for his basic system,

http://www.aquastealth.com/index.asp...PROD&ProdID=88
I am told is a pretty good setup as well.

and there are some setups out there even more sophisticated. I also have a link around here somewhere for fangling your own H2O system via McMaster-Carr parts catalog, will try to dig that one up.

[fanglemeister]

http://cybrina.mine.nu/Description.htm
one of the guys doing the mcmaster H2O setup. See the NACA link on his website, water injection was used extensively in WWII on supercharged fighter planes.

I also know of a guy running a non-intercooled Buick GN at 20+ psi on 89 octane gas using H2O injection with about 5% to 10% acetone, 50% water, and the balance methanol. The acetone is itself also a good cooling medium and burns very well, high octane like alky but reduces the spark energy required while simultaneously allowing more water to be tolerated due to its low flash point.

[slider_buck]

thats some good info and links. thanks guys