Performance/Tuning 2002

Since the last run you can see last year my main issues was to get rid of knock as much as possible and to get consistent boost. I did a lot of thing to achieve these goals. Replaced my CR42TS plugs with NGK UR6, which is one range colder. It helped a bit as the Aquamist kit did. I got quite low spark retard, but it was somehow inconsistent, as my boost. I played with the wastgate arm, replaced the WG solenoid, but it didn't help. Finally I replaced my ECM with a unit, which I dig out from a turbo Sunbird last year. Wow! Got consistent boost and very low retard all the time since then. I don't know what was the problem with the old unit, it might be just a reseating issue with the Ultimate. Anyway, hopefully this problem has been solved now. You can see the result below.



As you can see it was a power start and it's nice as it is. No spark retard, rock solid boost, quite a good working IC, good O2 values etc. My voltage is still down, but after I put on my new Optima and Powermaster I checked it with a digital multi meter at WOT and it was around 14V all the time. One remark here. My voltage was a bit better with the old ECM. This is in correlation with a few guys' report, who could improve the voltage in DM just by replacing their ECM's. * Anyway here is the performance with this run. Note that I let out before 1/4th mile, so this would be a 12's run according to DM.



* Now, that's the time when some interesting stuff can start. I've all the tools in my hand to fine tune the truck. I've just made my first runs with the wide band O2 and realized that I'm pretty rich. With 15 psi and 93 pump gas (European 98) I got ~11:1 air:fuel ration in 1st and 2nd and it goes below 10.5:1 in 3rd. Knock is zero, spark retard no more than 2 degrees around the TC lockup. That's with alky comming up at 9 psi. My plans to crank the boost up to 17 psi and start to lower my fuel pressure since I gonna get no more than 5 degrees of spark retard. If I reach that point I will raise the FP with 1-1.5 psi and leave it there. Hopefully that way I'll be able to find the optimum air:fuel ratio performance wise. In the meantime I also plan to do some runs with locking up the TC manually before the runs. Will see... *



It was quite a long ago I posted a new run here. This doesn't mean that I didn't test the truck that long, just there were nothing significant to talk about. A few things changed since my last run. I've a new exhaust which made my boost control a bit more wavy, so I had to loosen my WG's rod, which resulted in a slower spoolup in 1st. Now I guess I have to live with this. Have you noticed that AFR tgt values? Guess what, thanks to Dig and Leroy I can log the ouput from my WB O2 controller which you can see in the AFR tgt field. Unfortunately the displayd values are not the actual ration, but you might agree, it's still mind blowing that way too. 7.14 means 10.08:1, 12.75 means stoich. 5.7? Preaty rich... ;-) Just for the records the ambient temperature was around 78F during this run and this was the second and best run in a row. *



It was a 2 PSI power start and my rear tires broke loose a bit at the line. That's an issue which I've to deal with. My tires are like new and sporting 28 psi (in the rear) in them. Also a note that I tried an engine tie down the first time this day, but it loosed up at the first run so made no difference in the above run. I also locked up my TC the first time during this run and it made a difference. Between the two runs this day the only difference was the locked up TC and the second run was a .15 faster in the 1/8th beside the 20F higher intake temps at the start line before the 2nd run. * Next time I'll try out an improved tie down cable and will raise the boost to 17 PSI. After this the quest for the optimum AFR can start. * My root changed a bit since my last update. I tried out the tie-down cable, but in its current form it won't last more the one launch. Will look for this in the future, but currently it's removed. Since all my trouble started over with the stock boost control, I looped out the stock solenoid and add a 'grainger' type valve to control boost. Had to play with it a bit to tune it in, but this way I can get crazy spool up and quite consistent boost. It's now on 15 PSI, still needs some fine tuning before I can raise it a bit. Because the 'too good' spool up I hit over 16 PSI in first with a 14.5 PSI target. Will try to lengthen the WG rod, to eliminate this problem. Anyway I did a few run with this setup in its current form one night. The outside temp was around 75 F.



I turned down the fuel pressure a bit, so the AFR is a bit better, but still very rich. After my boost is on the target 17 PSI, I will play with the FP again. During the run the TC was locked. The launch was one of the bests so far. The great spool up had it result.



* Raising the boost is still ahead of me, constant 17 PSI is the goal with no knock. However with this setup I have to double check everything and keep an eye on the boost all the time, because the ECM can't pull out boost with the solenoid looped out. My other plan is to make the truck a bit lighter. Will talk about this soon... Hopefully I will be able ot do a few runs at the end of the next week, so stay tuned. * Ok. I've a new best. :-D The boost is still around 15 PSI, and I guess I reached the leanest point where I wanna be. Actually will bet back bit, because there were some knock during the run. My AFR still very rich at the end of the gears, especially in 3rd, but I can't solve this with FP adjustment, will require some chipping. The run was made on a cool nigh, temp in the low 70's.



A few words about boost. No that I have the grainger valve, I've two ways to set boost. Adjusting the valve, and adjusting the WG's rod. It's kinda a try and error type of game. The general rules that is you with the adjustment of the rod you will adjust spool up and boost, while with the valve you will adjust more the boost than spool up. Currently I'm backing up my rod, to eliminate spikes, but this lowers boost too, so I tighten the valve, to keep the boost on the desired value.



That was a pretty good 5 PSI launch. I'm quite sure that it could still be a bit better. TC was locked, but I had a few pounds of extra weight in the truck as well. Next step will be on the Hungaroring next Thuesday. Will see... * Thanks to Ave, I could make a run last time on Hungaroring with his G-meter in the truck. Unfortunately we picked the worst run of the evening, the semi-final where I clocked 9.052. Anyway here is the graph which Ave've drown.



According to the G-meter the 1/8th mile was 8.88 at 130 km/h. Hopefully we will be able to repeat this run with better results soon. Also, pls note that the HP numbers are no relevant at this time, because I don't know the exact weight of the truck. Anyway thanks again, Ave! You can see Ave's page with a lot of interesting stuff here. * Ok. So it's late fall now, so there won't be any performance improvement or any run at all this year, so I'm closing this page now. However before this, I'd like to post a last DM run. I was always curious, how accurate the DM "Quarter Mile Time Estimator" is? Well, I could record a run at Rabaring, on the last race of the season, so I can compare my DM's times with real life data. BTW that was the worst run that day, a bad launch, forgott to lock the TC in 2nd and had some knock in 3rd when the TC finaly locked. Anyway here is the run.



And the here comes the real life data: 60 ft - 1.81, 1/8 mile - 8.36, 1/4 mile - 13.45. I would say it's pretty close. Especialy till 1/8th mile. * So that's it. No more update on this page any more. I gonna open a new page next year and hopefuly will be able to improve this year's results...