Dyno coming up. . . tuning advice needed

[cpa]

But if you make an appointment at Group 5/AEBS, they're there [img]tongue.gif[/img] (and they're good). I went in this morning and I'll have to scan the data in later and post up the results. Nothing extraordinary to report unfortunately for my setup, (but at least I got the prelude injectors and air/fuel ratios pretty much straightened out for now), but I did have a few different observations and experiences with the MAP mod, Cartech, etc. for the group here.

[CROM]

Share you must...

[217gsr]

Definately let us know CPA. I think I might be getting my dyno done tomorrow afternoon. So hopefully you can post your results and anything else I might need to know while tuning my machine.

[cpa]

Hopefully the link works:

http://www.cartogra.com/home/ViewMyA...3&basedir=1287

OK, it worked for me [img]biggrin.gif[/img] !

Most all of the data is in the chicken scratch notes on the bottom and the notes to the run. The odd experience I had with the Cartech 2025i was trying to get the rise rate correct. Without the restrictor, and the needle valve all the way open, I ran way too rich, hitting 100 psi+ from a starting static of 48 psi and having an air/fuel lambda of about .79, or about 11.6:1. With about 8.5 psi boost showing that would say the rise rate was about 6:1. This seemed awfully high (I thought it should be about 4.5:1), but that's what it was.

So, I put the restrictor in the vacuum line to the Cartech and closed the needle valve all the way, figuring I'd work down from there. I was barely getting up to 60 psi fuel pressure and running lean and pinging in mid-range. After several runs fiddling with the Cartech, and going back and forth with the restrictor in, restrictor out, what I finally ended up with was my AEM FPR set to 36 static, the Cartech set to 54 static, the needle valve fully closed on the Cartech and max FP of about 68 psi. That would mean a rise rate of about 1.7:1 [img]eek.gif[/img] . But, at atmospheric, the jump between static on the AEM and the Cartech is 16 psi, so if I add that to the 14 psi of rise after the Cartech static, its 30 psi extra fuel or a total "rise rate" of about 3.5:1, which seems about right.

My air fuel lambda never went higher than .90 or about 13.2 at the low end, and from about 6,500 RPM up, it got richer to .85 or about 12.5:1. The restrictor with the Cartech seems VERY restrictive. Even though it says its not directional, I tried it both ways and indeed, it didn't make a difference.

My car is also running the MAP converter, but I hooked it up as in the JR instructions. I did not disconnect the IAT wires from the MAP converter as I believe others have done and have suggested. Based on my air/fuel ratios, I don't see it causing an overly rich condition on my car as others have apparently experienced.

My car is also running the water injection kit with 50/50 alcohol and water. The intake manifold seemed to stay noticeably cooler between runs, but it doesn't seem to be doing much in terms of a power adder. I wasn't expecting it to, I'm hoping the extra octane from the alcohol and cooling from the H2O will be helpful in the long run. On a side note, I can drive about 600 miles commuting using an extra overflow tank as a reservoir, before refilling.

Below is my last run compared to a previous visit. The previous run is without the MAP mod and water injection, using GSR injectors and the JR FMU. I've picked up a lot of torque and HP up to about 5,500 RPM on the graph. Most of this came from not having to run as much retard on the BTC after installing the MAP mod, and to al esser extent fuel. Above 5,500 its harder to compare because on the old run I "turned off" the additional BTC boost retard at about 5K rpm, but didn't do it on the most recent run today, and my BTC was at 0.3. On the old run, the BTC knob was at 1.0. My guess is I could do the same "turn off" and the charts would look much closer or equal above 5,500 rpm.

http://www.cartogra.com/home/ViewMyA...3&basedir=1287

My problem is that I have to sacrifice something as I have to add retard on the BTC knob to avoid mid-range ping (very evident pre MAP mod on the low end). This takes away from the top end now to a lesser extent. It's been the same issue before and after. That's why I think I want to go to an EFI PMS and bigger injectors and deal with the "trouble spot".

I am still having the problem of stalling out occasionally if I put the car in neutral at high RPMs and coast down. My idle is low though at about 550/600 rpms. If I moved it up, I think it would be better and stock is supposedly 750 +/- 50 rpm.

Also, one last side note, I think the fuel getting richer and the HP and TQ dropping off up top is a loose alternator belt. It's looking glazed and feels a bit loose. It also smoked during one run [img]eek.gif[/img] , squeals occasionally and my boost drops off up top to about 7.5 psi from 8.5 psi. I think I'll get a new belt and tighten things up a bit.

That's all I've got to say about that, your mileage and results will vary. Just thought this might be "interesting."

<font color="#a62a2a" size="1">[ August 06, 2002 12:01 PM: Message edited by: cpa ]</font>

[217gsr]

I can't see the photos, CPA.

Wow. . .sounds like you did a lot of tuning! I have no idea where to begin when (and if) I get to the dyno tomorrow. I disconnected my IAT wires from my MAP mod tonite, and I changed the FP settings to 34 (B&M), 40 (Cartech).

I still get some tip-in detonation. I had to increase my BTC setting to between 0.9-1.0 degrees retard/lb of boost. The top seems to pull harder than it did before, but I also seem to have lost some low end grunt.

I notice that the idle is a little more rough. . .and when the revs drop from higher rpms, the car comes "close" to stalling. . .but doesn't.

Any additional on-the-fly advice you can give me about tuning my fuel curves when I'm there would be greatly appreciated.

[cpa]

Damn, I hate it when the pictures don't work [img]mad.gif[/img] . Can anyone else get at them, or can I e-mail them to someone who is capable?

Anyways, I'm no genius at tuning, I started about where you are and we just watched the air/fuel ratios and fuel pressures, making slight adjustments until we got it pretty close, then did some minor tweaking. I would say start at something you are comfortable would be too rich. I left my Cartech at the rise rate my stock injectors were at before tuning, figuring that had to be safe with the larger injectors installed.

I also estimated what the FP "should be" using the FP formula at RC's site [(SQRT(New FP/Old FP))*Injector size] and knowing what my previous pressures were with my stock injectors. Essentially, figure out what pressures for the new injector size makes "equivalent CC volumes" between the two setups for static on the rail, at the FMU and at max boost. This of course assumes your previous set up was tuned OK and its not exact.

[CROM]

You can send them to me and I can host them.

Ill probably be asking you lots of questions in the near future [img]smile.gif[/img]

[cpa]

CROM -

I'll e-mail them to you, but did you try the links - I re-edited them from when 217gsr tried them. They work when I try them [img]confused.gif[/img] .

[CROM]

I can only see the one on the right and it is teeny tiny, how do I blow it up? Im not able to click on it or anything..

Do you have the stepper pulley or the JR Boost upgrade?

[cpa]

Click on the "Look at my album" link when you get there. Then it gets a little bigger, and if you then click on sections it will "zoom in."

I have the JR boost upgrade crank pulley. I've been thinking about the MVM stepper as well if I could get an answer on waht the maximum blower speeds would be. I also want to see how it does if I just get my alternator belt straightened out.