Weak 60'... not enough converter?
#1
Weak 60'... not enough converter?
I have a full weight A4 car that is street driven and raced when the weather allows. My currenty converter is a SY3500, I have 3.73 gears and 275/60-15 MT DR's. I haven't weighed the car, but it doesn't have many light weight parts.
It makes mid 400 RW #'s, the cam peaks HP at 6200-6300, TQ peaks at 4700-4800.
My suspension consists of: PA tubular K, UMI SFC's, BMR adj. TQ arm set on -2, QA1 struts w/ 275# springs, BMR LCA's & relo brackets, BMR adj. panhard rod, QA1 rear shocks, 21mm rear sway bar w/ poly bushings, the front sway bar has been removed. Lately I've had my QA1's set at 3 on all four corners.
The best 60' I've been able to muster was 1.699. The other 3 passes were weak as well - 1.769,1.729, 1.704 The last track outing, wheelspin was not an issue. I just couldn't seem to get the car to leave hard enough and the ET's suffered.
I'm begining to wonder if the converter is just too soft. It's a 1.63 STR and flashes to about 4200-4300 RPM.
I want something efficient so that the car can still be driven daily if needed, but something that will hit arder and get the car out of the hole better.
It makes mid 400 RW #'s, the cam peaks HP at 6200-6300, TQ peaks at 4700-4800.
My suspension consists of: PA tubular K, UMI SFC's, BMR adj. TQ arm set on -2, QA1 struts w/ 275# springs, BMR LCA's & relo brackets, BMR adj. panhard rod, QA1 rear shocks, 21mm rear sway bar w/ poly bushings, the front sway bar has been removed. Lately I've had my QA1's set at 3 on all four corners.
The best 60' I've been able to muster was 1.699. The other 3 passes were weak as well - 1.769,1.729, 1.704 The last track outing, wheelspin was not an issue. I just couldn't seem to get the car to leave hard enough and the ET's suffered.
I'm begining to wonder if the converter is just too soft. It's a 1.63 STR and flashes to about 4200-4300 RPM.
I want something efficient so that the car can still be driven daily if needed, but something that will hit arder and get the car out of the hole better.
#5
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Had the same problem in my old car. 3400 stall, MS4 cam only, and Nitto's. Could only muster 1.799 60' times leaving as hard as she could with no tire spin. Had her footbraked all the way to just before she pushed through the brakes and gave it full go on green. I also contributed it to not enough converter.
#6
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My ss4000 i cut 1.5x's at my old track. I just went to the track around here and it was straight crap, no traction at all and the best I could do was a 1.70 spinning my *** off.
I left at around 2800. Did you try leaving at different rpms? With that kind of power you should have a better 60'.
I left at around 2800. Did you try leaving at different rpms? With that kind of power you should have a better 60'.
#7
I foot braked it to 2200-ish RPM a few times, and flashed it from 1200-ish other times. Seems to 60 foot about the same. With the 275/60's, traction really hasn't been an issue. At most, I get a scuff from the tires on the initial hit - and then it just lurches forward.
I was really expecting mid 1.5's from this car. I went mid 1.7's with this same converter when the car was just bolt ons and 3.42 gears on a 255/50-16 DR. Something just doesn't add up.
I was really expecting mid 1.5's from this car. I went mid 1.7's with this same converter when the car was just bolt ons and 3.42 gears on a 255/50-16 DR. Something just doesn't add up.
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#10
I had 4.10's, they were a little too much. I also tried 26" tires with the 3.73's, not enough traction. Ideally, I'd like to leave the 3.73's. I was thinking 3.90's though after my last trip to the track. I was right around 5900 RPM comming through the traps.
I guess I was wrong in my assumption that I had enough motor to overcome the gearing/28" tire on the big end.
I guess I was wrong in my assumption that I had enough motor to overcome the gearing/28" tire on the big end.
#11
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have you ever tried to adjust the shocks? any videos of the launch? Even though it isn't spinning it still may also be a setup issue. seen cars pickup .1-.2 after just adjusting the shocks to get the right amount of weight transfer and keeping the rear from squatting basically just optimizing the suspension to use every bit of energy as efficiently as possible.
#12
I've tried a couple of different settings, it lifts the nose up - but nothing too drastic. I'll have to post the recent vids of the car tonight when I get home.
Here's a vid of the car with 255/50-16's, the front QA1's set on 3, the left rear set on 3, and the right rear set on 4 - with 45lbs of ballast in the spare tire well. I had around 5/8 tank of gas on this run. I ended up with a 1.729 sixty foot on this pass. If you turn the sound up enough, you'll hear when I have to get out of the throttle on the 1-2 to keep it straight.
http://nz.youtube.com/watch?v=aRiPav2JRJk
On the 275/60-15's - I never had to lift, just planted my right foot and pointed it straight. I took out the ballast and set my right rear to 3. I talked to a fellow racer (Caveman from this board) and he advised me to set them all on 3. His silver Formula had a similar set up to mine and worked well at OSW with the QA1's on 3 all around. Given the fact I had traction last time out - I'd say it's working decent, hell... almost too well.
I'll have to post the vids of the two recent runs. The car comes out soft and acts kind of lazy until it gets some momentum.
Here's a vid of the car with 255/50-16's, the front QA1's set on 3, the left rear set on 3, and the right rear set on 4 - with 45lbs of ballast in the spare tire well. I had around 5/8 tank of gas on this run. I ended up with a 1.729 sixty foot on this pass. If you turn the sound up enough, you'll hear when I have to get out of the throttle on the 1-2 to keep it straight.
http://nz.youtube.com/watch?v=aRiPav2JRJk
On the 275/60-15's - I never had to lift, just planted my right foot and pointed it straight. I took out the ballast and set my right rear to 3. I talked to a fellow racer (Caveman from this board) and he advised me to set them all on 3. His silver Formula had a similar set up to mine and worked well at OSW with the QA1's on 3 all around. Given the fact I had traction last time out - I'd say it's working decent, hell... almost too well.
I'll have to post the vids of the two recent runs. The car comes out soft and acts kind of lazy until it gets some momentum.
Last edited by 86 IROC; 09-12-2008 at 01:04 PM.
#13
Videos as promised:
11.313 - http://nz.youtube.com/watch?v=7d7WJfsExxs
11.413 - http://nz.youtube.com/watch?v=kkosFkr7VWU
11.313 - http://nz.youtube.com/watch?v=7d7WJfsExxs
11.413 - http://nz.youtube.com/watch?v=kkosFkr7VWU
#15
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Doesn't look like it has good weight transfer. Is the front swaybar removed? What is the tire pressure at? I know each car and track is different, but I set my QA1's on either 1 or 2 in the front and 6 or 7 in the rear. It's depends on actual track conditions, but those general settings have worked for me over time. You mention the pinion angle is set at -2, but does the front nose of the rear end pumkin face downward?
#17
Doesn't look like it has good weight transfer. Is the front swaybar removed? What is the tire pressure at? I know each car and track is different, but I set my QA1's on either 1 or 2 in the front and 6 or 7 in the rear. It's depends on actual track conditions, but those general settings have worked for me over time. You mention the pinion angle is set at -2, but does the front nose of the rear end pumkin face downward?
Tire pressuree was 18psi, front sway bar is long gone. I'd have to look at the rear, but I don't believe it faces downward. FYI - full tank of gas for these passes as well. Next time I'll be trying 1/2 tank.