Went to a real track for the first time in life to find out just how I succeeded with my Procharger tuning.

First attempt: I roll up for staging and prior to launch I powerbrake and rev it up to 2000 rpm, and the on the green light I punch it. Result: Massive wheelspin, at least first and second gear, E.T 16.9

Second attempt: I roll up for staging, hit the brake, and when the light turns green I simulatneously release brake and floor it.
Result: E.T 14.037, Trap Speed 159.85 km/h

Need some hints from you other guys'n gals that run Prochargers on proper launch tehcnique.

The fact that traction is the problem now, probably means I worked out all tuning issues!

 

Now you need to go over to the Chassis board and get started on some suspension mods & tuning and pick up some drag tires.

Until then don't floor it all at once. The throttle isn't a push button, it has more positions than "on" and "off" Try launching off the brake at around 1000-1200 rpm*. release the brake at the last yellow* and give it about half throttle*. As the car begins to accelerate, then slowly, gradually, roll your foot down on the throttle*. Give it as much throttle as you can as quickly as you can with the least tire spin possible.

*Things with an asterisk will vary as to when, how much, and how quickly you can (or slowly you must) do them depending on you and your car. Experiment! with practice you will learn how quickly you can roll onto the throttle and get the best launch.

 

I like the build power, then build traction, more power, more traction, etc. etc. because of this I like to have a transbrake against a correct converter with full power at launch. Lose the front swaybar but not the rear, lakewood drag struts/shocks, eibach launch kit with 60 psi in the bag (screw the 30 psi limit), full spohn (see ad banner above) setup with adjustable tq arm adjusted for about 6 degrees down pinion angle on et streets. lookout!

 

my favorite thing, learning how to launch a car! i'm running that motor, with that charger, but i have a six-speed so it's different. my advice is to find a quiet country road, no cars, no houses. take your g-tech, and try different things. see what works best for your combo.

 

ZaphodB you have PM!

 

Yeah, I am going to try that. Must find someone close with a g-tech or buy one myself first...

My first real testing was at the track since I was going there with a friend anyway.

It turned out that I probably had more power than I expected. Probably fun to watch but I didn't get any good times due to my inexperience in launching with the supercharger installed....

 

Replied to your email instead because pm:s were only allowed 2000 characters and I had a longer reply

 

159.85kph converts to 99.33mph, which works out to fairly close to what a street car running 14.0 should run in the ¼. A bit confused though, is this the car in your sig, a supercharged 5.7??? What was your 60’?

Are you at a very high elevation or something?

I’ve run a 13.6075@99.9869 with my pretty much stock ’87 formula 350 (cold air intake, cat back and sticky tires).

 

In my opinion street tires wil continue to go up in smoke. Get some ET Streets for track use only and solve the problem. I have had to switch to full time drag radials for street use and ET Streets for the track.

 

just buy your own. then you can also figure out your lateral g's.

 

OK, what am I missing here? The trap speed is a pretty good indicator of HP produced and getting through the drivetrain and et is an indicator of how efficiently you're using that power/getting it to the ground.

The fact is that at best he's only got the MPH to run a high 13. I've hooked my car to 1.8 60' times at this power level on 16y/o goodyear ZR's.

Much bigger or stickier tires will slow the car down. I've run within .04s of my best 'sticky tire' pass on the radials, the car just doesn't have enough power to go faster. If I heat a set of drag radials I could hit it as hard as I want off the line and the tires won't spin.

 

One thing whats missing is probably the right launch tech, this was my first trip to the track ever.

On the best of the two runs my 60 foot was 2.258s, but the thing that gets me thinking is that my 200m time is a full second better on my first run
(When I spun so much in the first half of the run that I got a bit scared and backed off the throttle) 7.409s vs. 8.482s...

 

Man, you crazy Europeans and your wacky metric system, had to whip out my calculator to figure out that that 200m is almost exactly an 1/8 mile…

Hum, that makes things a lot more interesting, you’re saying that you ran a 7.409 1/8 with a 2.258 60’… wow. That’s a low 11 second pass spinning, probably a high 10 if you hooked. Even the 8.4 on the second pass should be a mid 12… did you let off on that one also (if not then you’re having problems for the second half of the pass)?

That being said, you’ll never hook that on radials. You’ll need a DOT Slick or a full on slick to hook that. You might be able to get away with a good set of big DR’s, but without some skill driving and tuning to make it work.

Technique? With a slick type tire you want to heat them pretty well, pull just past the water box and heat them for about 4-5s in second gear after you start seeing tire smoke (in other words, counting 1 one thousand, 2 one thousand, 3 one thousand…). Stage it and assuming that it’s an auto, you’ll probably see your best time by holding the brake and just as much gas as you can give it without spinning the tires and then when the tree comes down letting go of the brake and just about flooring it.

 

Dahlhems säljer G-tech....

Kul att du fått ordning på grejorna.....

Jag har beställt lite grejor från BMR hoppas på bättre fäste jag me'.....

In english:

Dahlhems speedshop sells G-tech....


I've ordered some stuff from BMR hopefully I'll get som beter traction too......

 

To avoid confusion, here's the complete data for both trial runs:

#1: Starting at about 2000 rpm. So bad traction that I let off a little after a while.

60 foot: 3.062s
1/8 mile: 7.409s
1/4 mile: 16.956s @ 139.93km/h

#2: Flooring it from a dead stop

60 foot: 2.258s
1/8 mile: 8.482s
1/4 mile: 14.037s @ 141.18 km/h

And I think you're right that I am having somekind of a problem in the later halv of the 1/4 mile, most likely too much fuel under boost, since it doesn't seem to accelerate as good after 1/8 mile... Any ideas?

 

It could be your ignition system getting bogged down under full load and full advance. If you haven't beefed that up yet, you need to. The engine might not miss, but without enough power a good flame kernel can't properly form.

 

To be honest those #'s are so all over the place that it's hard to guess without seeing the car.

The initial information basically showed that you had a high 13second car, now as you've added information it seems like you might have a 10 second car or better with some real problems.

I think I've answered the basics of the traction issue, I'm not sure what to make of the rest of the times. You didn't say if you let off on the second run, but if you didn't you lost about 1.5 seconds somewhere in the second half of the run. Actually, the more I play with those numbers and compare them to ‘normal’ runs, the weirder they are. For example, with the second run, if you accelerated at the same rate in the second half as in the first half of the run you should have run a low 12 in the 11x mph (about 180km/h) range, but even if you just ran the average speed between what you should have reached in the first half and the MPH indicated at the end of the run you should have run .5s faster. So in other words on that second run you appear to have run the 1/8 at about a high 12s pace (low 12’s if you had a better launch), but the second half at a 14.5-15s pace, which is just about absurd unless you hit the brakes or blew something up.

The first run is even more extreme, since you ran a full second faster in the 1/8 while everything else was MUCH slower (the 60’ was .8 seconds and the ¼ was almost 3 seconds

I don’t know what to make of this. One guess would be that you’re not feeding it enough gas at the top end (fairly common with cars that lay down at the high end, even that have been dyno tuned, since a drag strip will usually place a higher load on the engine requiring more fuel in a boosted application then a dyno.

I suppose that I could have messed up my conversions somewhere…

 

7.4 in the 1/8 isn't close to a high 10 second from my experience......you have to be close to the 6.90s-7.10s to be even close from my experience and that is everything from boosted cars to n/a cars

BUT

that 7.4 could be a 10 second pass if he is spinning really bad and making 9 SECOND POWER...but i doubt thats the problem here

 

No, a 7.4 is probably a mid 11 second pass, but he said he ran that 1/8 with a 2.25 60', where a more typical 60 for having that much power is in the 1.4-1.7 range, which would easily put him 1/2 a second or more faster in the 1/4... Of course, like I said, none of his MPH's show anything near that so who knows what's happening. I'm beginning to wonder if the clocks at the track were messed up...

 

So all-in-all you've got a setup that's making some good power. Get some sticky tires and let us know what the times are.

 

You're probably right, because I am getting suspicious when I get better times on the street than I get on the track.

Did some testing using Craigs ecm software to get 1/4 mile times today, and I got better times than I did on the track.
60 ft. 60 mph 1/8 1/4
#1: 2.00s 5.13s 8.72s @ 84.88 13.64s @ 99.39
#2: 1.85s 4.46s 8.30s @ 84.88 13.31s @ 77.72*
#3: 1.98s 4.90s 8.68s @ 82.78 13.57s @ 100.16
#4: 1.84s 4.77s 8.50s @ 82.32 13.41s @ 99.89

Run 2 would probably have been below 13 if I dind't have to hit the brakes because something showed up in the opposite direction on my test road....
But all three were pretty close in time, only was like .1 s difference. This was with street tires and a passenger that handled the laptop....

I am going to dig deeper into this tomorrow, and hopefully get things even better - didn't wanna do to many test runs in the same place today, because it might attract unwanted
attention...