Friday, December 19, 2008 - 01:36 am, by: Khris Cox(Kc95sc400)
Went to Darlington dragway in South Carolina last night. Conditions less than perfect. About 66 degrees and VERY humid. I could feel the moisture in the air. So I think the track was a bit wet not to mention the air density.
Anyway, best run -
RT - .121 60 - 1.872 (only half way descent 60 I got all night) 330 - 5.386 1/8 - 8.208 @ 87.26 1000 - 0.0 (not listed for some reason) 1/4 - 12.685 @ 110.67
This is very good considering the damp air and track. I had a can of octane boost that I forgot to put in. My runs steadily got worse after that run, crappy 60fts and lower mph's.
If I could have only managed to hit that 1.8 60ft again. Oh well. I still think I could run (very) high 11's with some good air and a good set of sticky tires.
I have some in car video I'm going to upload a bit later by the way.
KC
Adam Peterson Goo Roo Western Australia Supercharged & Intercooled V8 coming
Friday, December 19, 2008 - 03:11 am, by: Khris Cox(Kc95sc400)
Adam
350rwhp on a dynojet, which are said to read on the high side. But, I don't think my convertor was locked on the pulls.
I made the run with OD off and the convertor was definately locking hence the extra 2mph difference in trap speed. I don't usually run with OD off.
I am very sure I could've run a few tenths faster if I was hooking better. I've run an 8.01 at the local 1/8 track which is 2 tenths better than the 1/8 time on the above run.
Speaking of exhaust, I blew the collector gasket on the drivers side again, between the header and the rear exhaust. I was running a bit rich as a result, likely partially explains my trap speeds going down a bit.
I have the EKT / IMF headers. 2.5 inch custom mandrel bent exhaust put together from pre bent pipes. Three Magnaflow mufflers. One tru-x dual in / out and a pair of straight throughs in the rear. If you go back a page or two there should be some pictures.
Wednesday, January 21, 2009 - 02:44 pm, by: Khris Cox(Kc95sc400)
Long time no update...haha.
After tons of trouble and a few different tries, I finally have the Hoosiers on a pair of wheels that I think will be ok. Just not sure if they will hit when the car squats. I ended up having to roll the fenders a bit.
I had all this done in time to head to the track this past Saturday but mother nature screwed me up. Tracks were closed Saturday due to freezing temps and closed Sunday due to rain.
So, hopefully this coming weekend I'll be able to make a few passes!
And, I have a question for you guys. What's the lowest 60ft times you guys have seen on stock drivetrain parts? I have to admit I am a little nervous.
Friday, January 23, 2009 - 01:17 am, by: Khris Cox(Kc95sc400)
Thanks, guys.
Daniel, thanks for the 60ft info. The fact that you consistently run 1.6's and 1.7's makes me feel better about the strength of everything.
I do have to disagree with you though on what my car will do. I have over estimated the performance of my car in the past and there is no sense starting an argument, we'll just have to wait and see, but I think the car will do 1.6 - 1.7's all day and maybe even dive into 1.5's.
Keep in mind I have hit a couple of 1.78-1.79 60fts on the street tires and I have had quite a few in the low - mid 1.8's.
Hopefully the weather will be good this Sunday and I'll make it to the track. Can't wait!
Khris
Oh and also keep in mind, on the street tires I cannot launch anywhere near my 2800rpm stall.
Thursday, March 05, 2009 - 11:33 pm, by: Khris Cox(Kc95sc400)
Hey guys, long time no post.....
A few updates:
I have not had any luck the last few times at the track, ever since I ran the 12.65 at Darlington. My 60fts (even with the slicks) and mph have been down a bit. I think it was a tuning issue. I have made a few changes but haven't run since.
I have made a few small changes here and there to a few other things. I did discover that over using octane boost will screw up spark plugs.
I have installed a Suprastick! Haven't been to a track yet to tune it for WOT but otherwise I pretty much like it. My shift tables still need a lot of work, don't much like the included base table.
Later this afternoon I will be going to the local 1/4 track for a test in tune. This is the track that was built last year and it's about 20 minutes from my house, 2 minutes from my work. This is the first test and tune they've held. Will likely be very busy but I'm hoping to get some good runs in. If I've fixed the tune issue I had and tuning the Suprastick goes well I'm looking forward to running some good times.
On a side note, I put in some 100 octane last night.
I'll try and update with some times later.
KC
Peter Nitschke Junk Filterer South Australia UZZ30 UZZ31
Saturday, March 07, 2009 - 10:37 am, by: Daniel Clarke(Dieseltrain)
You will find if the car isnt making enough power on the slicks it will bog the engine down... Normally you wouldnt notice this as it would allow wheelspin and the motor to keep the torque there and rpm's rising.
What Tyre pressures were you running on the Slicks ? i would recoomend starting really high and working your way down. If anything, a fraction wheelspin would be good as it wont bog it down, but will grab and throw it outta the hole.
This is why we all run ET Street Radials, Full slicks are way to harsh and offer way to much traction, and have to be run at such lower psi, it effects your mph.
Saturday, March 07, 2009 - 12:21 pm, by: Khris Cox(Kc95sc400)
Ok guys, mostly another bad track night.....blah.
This track is technically awesome. Brand new, all concrete, close to me but it was very very busy and I only got three runs in for the 5 hours I was there.
Times and Suprastick tuning.....I don't have the slips in front of me but times are close.
First run was a 13.58 with a 1.9 60ft. I hit the rev limiter very hard for the 1-2 shift, I had to let off the gas to make it shift. I then took some speed out of the 1-2 shift and added some speed for the 2-3 shift. Second run was a 13.28 with a 2.1 60ft (I spun on this one). This is a good improvement, ran about 3 tenths faster despite losing 2 tenths on the 60ft. I still hit the limiter for 1-2 but I didn't need to let off, I also hit the limiter on the 2-3 shift. So I took more speed out for the 1-2 and put the 2-3 back where it was. 3rd run was a 13.3 with a 2.2 60ft (bogged down on this run). Again, same et despite the slower 60ft. I still bounced a little on the 1-2 and I think I bounced on the 2-3. All of my trap speeds were in the 108-109 range which is decent considering my highest ever was a tad over 110.
None of those times are good but at least I could see the improvement as I tuned the Suprastick.
Daniel,
What you are saying makes some sense but I'm not convinced it's not a tuning issue. The Hoosier's are equivalent (I'm pretty sure) to the MT streets. They are not a full slick and they even have DOT numbers. I usually run them at about 24psi (which is high) and I have only spun once or twice using them. I do think it is possible that maybe too much traction is part of my problem, I have noticed that the higher I try to stall the worse it bogs.
But, regardless, I do have a tuning problem. Before I go into the details, remember that the MAFTPro that I am using has auto AFR tracking for boost. The auto tracking, once enabled, adds or subtracts fuel to keep the AFR at the set amount. It is enabled by throttle position, map pressure and RPM, all of which are adjustable of course.
I started having problems when my collector gasket blew during the 12.68 run or the run after. I made about 6 or 7 more passes that night and couldn't break a 13 and my mph's were down to 106-107s. I fixed that gasket the next day and so far, it hasn't been a problem since. But soon after, I started having another problem. With mid or so throttle and load (around 98 to 110 or so map) the car would surge very badly with the AFR sweeping back and forth from very rich to very lean. My first thought was that I had the MAFTPro starting the AFR tracking a little too early (with the ECU still in closed loop) and the MAFTPro and the ECU were trying to compensate for each other. So, I set the the TPS setting higher so that the auto AFR tracking wouldn't come on until the ECU was in open loop. This stopped the surging but was causing the engine to run way too lean for the first couple psi of boost. So next, I added a bunch of fuel where needed to keep it rich until the auto tracking could start doing it's job.
Now, I admit I'm a little slow but I just noticed last night on the way home from the track how rich I'm running under boost. When I say rich, I mean it was going 10 - 11 to 1 with the AFR tracking taking out its max of 15% (the most I have it set to lean out). I took out a ton of fuel and the auto tracking is taking out 15% and it's still barely holding the AFR at 12.5 - 13 to 1. But, now that I've taken all this fuel back out, it's surging and acting crazy again mid load.
I did not have this problem before I fixed the exhaust gasket leak problem. Should also be noted that the side that kept blowing out on me (happened twice) is the side with the wideband. The only thing I can think of is that since I had put on the header back exhaust, I've always had a leak there and now that I've fixed it, my tune is way off.
I don't know, I'm still scratching my head trying to figure it out.
Sorry for the long post, anyone who made it through deserves a beer! Hopefully it makes sense, makes sense in my head.
Saturday, March 07, 2009 - 03:41 pm, by: Daniel Clarke(Dieseltrain)
Also, Stickier tyres and like slicks also provide a little less mph than the usual street rubber does.
Could the tune be affected by the increased traction, which is providing more load on the motor and making it richer as the motor cannot spin up as higher or freely if its breaking traction ?
Tuesday, March 10, 2009 - 02:01 pm, by: Khris Cox(Kc95sc400)
Quick update.
I went to the local 1/8 track yesterday. Ran much better although still not great. Best of 8.349 I think it was. Good considering my best 1/8 at the quarter on Thursday was an 8.6 something. My runs weren't very consistent seeing as how I was tuning both the Suprastick and the MaftPro. I think that the better times were mostly due to fuel tuning. I wasn't running nearly as rich although still a little rich off the line. Had a few low 1.9 60's and traps were in the 85-86 mph range.
I feel a little better now. Should also be noted that it was windy as heck and the ambient temp was about 25 degrees hotter than when I ran the other night.
But, I definately do have something weird going on and I'm not sure what it is. Same problem as stated above. Goes very lean around 3000-3400rpm for no apparent reason. Doesn't seem to be dependant on load or throttle position and it does it in all gears, or at least in 2nd and 3rd. If I keep it in 2nd with mid throttle, it's fine until about 3000 and then it just goes lean. Does the same thing in 3rd. I can tune out the problem but I can't help but think something is wrong. It's fine boosting and light cruising as far as I can tell, just happens mid load at the stated rpm and no boost.
Any ideas please share!
My suspects are: vac / boost leak, exhaust leak, fuel pressure regulator maybe, tps sensor problem, rpm signal problem......... not really sure where to start though.
Friday, March 20, 2009 - 01:28 am, by: Khris Cox(Kc95sc400)
Update:
Ran the 1/4 last night.
2 weeks ago my best run was a 13.293 with a 2.102 60ft and a 108.28 trap. Last night my best time was a 12.895 with a 2.041 60ft and a 109.51 trap.
Conditions were very close to the same. 2 weeks ago it was about 45-50 degrees, dry and calm. I only got to make three runs due to the volume of cars. Last night was about 45-50 degrees wet / sticky and calm. Was only able to get 3 runs in due to everybody breaking their cars.
The only changes I made were tuning. I logged two of my runs and I am still diving down to 10.5 to 1 on the launch, although its just a really quick spike. I don't know if this is why I STILL can't get low 60ft's with the slicks. It did not feel like it was bogging like it had been lately. But my best 60 was still only a 1.997
So, in conclusion, I definately have made an improvement just by tuning. I don't really know what to do with the tires. They have done nothing to help me so I am considering selling them and getting a pair of drag radials. I'm going to keep playing with the tune, there is still room for improvement. I feel good about the times I ran last night. For my car, they are good considering the lousy 60fts.
Friday, March 20, 2009 - 06:13 am, by: Khris Cox(Kc95sc400)
Yes, it is 2800rpm but....I did notice something interesting watching the MAFTPro logs. It seems as though the Suprastick is locking it at about 2000rpm despite the fact that I have the stall speed set to 3200rpm. I can see this watching the RPM on the log.
The Suprastick doesn't read the RPM signal very well, it jumps around a bit. I'll have to try raising the stall setting to see if it changes anything.
I was thinking that the next go at the track would involve the street tires / wheels. I am also considering some drag radials on the Supra wheels seeing as how my current rear tires are about burnt out anyhow.
Friday, March 20, 2009 - 11:13 am, by: Daniel Clarke(Dieseltrain)
Ahh, SO do you have it set to lockup in 1st gear as well as 2nd and then 3rd ? i wouldnt worry about locking it in 1st champ, let 1st get right through into 2nd then start engaging lockup . Otherwise it will bog the motor down too much in 1st.
See what happens is you set lockup for 3200, once it gets to that rpm it locks up which drops almost 1000rpms so the suprastick is probably doing what its told, but this then turns your 2800 convertor back into a 2000 jobby .
I would leave 1st gear open, then utilise lockup once in 2nd then 3rd gears, i reckon that will get your 60's rigth down where they should be
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