Enough tire? - and other questions.
Enough tire? - and other questions. So I don't get long-winded, I'll put this in a question/answer type format:
I took the advice of you folks who post here frequently and swapped out the Yank SS3600 converter for a PT (4000) series.
Now, I need your advice on how to make it work for me at the track.
1. I've been told the 275/17 MT DR's won't dead hook anymore, but, I'm not at a huge power level and I think they'll still hook with a few suspension adjustments. Do you agree?
2. With the old SS3600, I'd heat the M/T's (17 psi [hot]) and launch at 1800-2000 rpm. With the PT4000, should I now stall it to around 2800-3000 and leave with less foot into the pedal?
3. If my BMR TA is set for -1.5 pinion angle and LCA's are in bottom relo bracket hole, should I set the pinion angle to 2.5 or 3.00 to accomodate the new converter?
4. Which hole should the LCA's be set in the relo brackets for the best hook traction, generally speaking?
Let me know what you think ...
. My suspension is in the fquick link in my sig.
Thanks!
I took the advice of you folks who post here frequently and swapped out the Yank SS3600 converter for a PT (4000) series.
Now, I need your advice on how to make it work for me at the track. 1. I've been told the 275/17 MT DR's won't dead hook anymore, but, I'm not at a huge power level and I think they'll still hook with a few suspension adjustments. Do you agree?
2. With the old SS3600, I'd heat the M/T's (17 psi [hot]) and launch at 1800-2000 rpm. With the PT4000, should I now stall it to around 2800-3000 and leave with less foot into the pedal?
3. If my BMR TA is set for -1.5 pinion angle and LCA's are in bottom relo bracket hole, should I set the pinion angle to 2.5 or 3.00 to accomodate the new converter?
4. Which hole should the LCA's be set in the relo brackets for the best hook traction, generally speaking?
Let me know what you think ...
. My suspension is in the fquick link in my sig. Thanks!
hate to be a jerk but to answer your questions on tires and launch - you can only go out there and see what the track holds. the internet wont tell you. if she consistently spins, you will need the help of a taller sidewall drag radial.
on teh tq arm position and lca - mess with one thing at a time. 1.5 negative of (theoretical) pinion angle is just fine. it really doesnt effect the car as much as most think. lca relocation should be in middle hole if you are not lowered. the lowest hole will just put more load on teh rear tires. sometimes that isnt always a good thing
good luck and enjoy testing.
on teh tq arm position and lca - mess with one thing at a time. 1.5 negative of (theoretical) pinion angle is just fine. it really doesnt effect the car as much as most think. lca relocation should be in middle hole if you are not lowered. the lowest hole will just put more load on teh rear tires. sometimes that isnt always a good thing
good luck and enjoy testing.
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From: Gainesville, Florida # of drag strips runs: ?!?!?
I wouldn't launch it much above 2200-2400 rpm. You still want the car to launch and not push off the starting line. I'm also surprised you don't run more air than 17 psi, have you tried higher?
Derek
Derek
Both Gents above make some good points. Your going to have to experiment. Try 20lbs. hot in the tire. I run 22lbs hot on an unpreped track and can dead hook evey time, with my 275/50/15s. Good luck and let us know how it works out.
1. Yes, but it wont be easy with your suspension. A 17" radial and I'm assuming heavy car will need 12 way adjustable shocks for best results.
2. Something you have to play around with. I always had best luck flashing 4l60e converters.
3. No, the extra stall will offset the decreased STR. It'll prolly hit around the same maybe even harder now. Plus, as Gator mentioned, its not that big of a deal anyways
4. At your power level, you should be able to use the bottom hole.
2. Something you have to play around with. I always had best luck flashing 4l60e converters.
3. No, the extra stall will offset the decreased STR. It'll prolly hit around the same maybe even harder now. Plus, as Gator mentioned, its not that big of a deal anyways
4. At your power level, you should be able to use the bottom hole.
You are gonna get mixed advice here as people have different combos with lots of different parts.I would leave at min of 2000 rpm,and sneak up on it making minor changes to see what the track will hold for you(tire pressure,shock settings,ect).I can tell you from running Yank converters, my car will go 1.45 leaving at 2500, and if the track will hold 1.40 leaving at 3500.Pt series likes to be stalled up not flashed,IMO.Do you unbolt the front swaybar when racing?
Good advice from all ... looks like I have a lot of track time ahead of me to play around with many adjustments. Front sway bar is a Strano hollow 35mm bar, but, I removed it completely ... weight reduction is just back seat removed, along with rear seatlelts, spare and jack. So, it's pretty much a full weight car. Here's my suspension stuff ... pretty basic 
:
Suspension/Chassis:
Heavy Duty Bilstein Shocks (old style, not SLP)
BMR adjustable TA @ -1.5
Front 35mm Strano sway bar
Rear BMR 22mm chromemoly solid bar
BMR Weld-in Sub-Frame Connectors
Lower Control Arms
Panhard Rod
Driveshaft Safety Loop
Relocation Brackets
As for the 275/17 M/T DR's, I did like the M/T website suggested and started at 16 psi and worked my way up to 22 psi. They seem to work best at 17-18 psi with a hard 5-6 second burnout ... at least for me.
:Suspension/Chassis:
Heavy Duty Bilstein Shocks (old style, not SLP)
BMR adjustable TA @ -1.5
Front 35mm Strano sway bar
Rear BMR 22mm chromemoly solid bar
BMR Weld-in Sub-Frame Connectors
Lower Control Arms
Panhard Rod
Driveshaft Safety Loop
Relocation Brackets
As for the 275/17 M/T DR's, I did like the M/T website suggested and started at 16 psi and worked my way up to 22 psi. They seem to work best at 17-18 psi with a hard 5-6 second burnout ... at least for me.
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My mods are in my sig so you can compare....but 275/17 MT ET Street Radials hooked for me with my PT4400. That's stock Bilstein Level II suspension and I cut a 1.63 short time. I really didn't think they'd hook, but they surprised me.
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PT4400 on 275/40/17 mt drag radials, ONLY has shocks for suspension and no front sway bar, 1.59 60ft 11.66 at 117.0, leaving at 1000rpm and flashing it
PT4000 on 275/40/17 mt drag radials, hal shocks/springs, bmr tq arm, umi lca's and panhard rod, no front sway bar, flashing it would net me 1.58-1.60 dead hook EVERY pass, leaving at 2700rpm dead hooked to a 1.54 60ft. The car had more in it, I was afraid of breaking the driveshaft so never launched any harder. It did pull the front heavy 17's a solid foot also. Also this combination went wheels up quite a few times on the street and left hard.
Keep playing with it until you get it to hook.
PT4000 on 275/40/17 mt drag radials, hal shocks/springs, bmr tq arm, umi lca's and panhard rod, no front sway bar, flashing it would net me 1.58-1.60 dead hook EVERY pass, leaving at 2700rpm dead hooked to a 1.54 60ft. The car had more in it, I was afraid of breaking the driveshaft so never launched any harder. It did pull the front heavy 17's a solid foot also. Also this combination went wheels up quite a few times on the street and left hard.
Keep playing with it until you get it to hook.
1.63 is not hooking imo with that converter. I would run some real tires (15") at the track. Why screw around with 17's that won't hook consistently? One track they could hook 1.5's, the next probably 1.8's. You can't really ask people what works unless they run at YOUR track all the time.
Also start with your air pressure higher and work yourself down, not the other way. Get the lca's closest to level without pointing down toward the front. I would get some front shocks for better weight transfer. That along with good tires, you should see 1.5's atleast.
Also start with your air pressure higher and work yourself down, not the other way. Get the lca's closest to level without pointing down toward the front. I would get some front shocks for better weight transfer. That along with good tires, you should see 1.5's atleast.
i would think that if you worked on the launch technique - you could go 1.55 60' at BMP without messing with anything (just the driver mod), you wont be able to go all out on those tires. there will be some compromise IMO
I agree with most of what is being said. I'm with John ... driver mod and a lot of track testing, i.e., launching at different rpm and trying to flash the converter from lower different rpm. Once I get the 'driver mod' down pat, I think then ... and only then .... would be the time to start moving the LCa's, playing with tire pressure, and adjusting the torque arm on the car.
Just gives me morE time to do what I love ... RAAAAAACING!!!!!!!!! I'll post up any gains I see on Friday night. Hopefully, I can get several runs in since a lot of folks will be up at the Gator Nationals ... of course, it's gonna' suck BAD if it's all ricers with no big slick cars so I can run in their groove.
Just gives me morE time to do what I love ... RAAAAAACING!!!!!!!!! I'll post up any gains I see on Friday night. Hopefully, I can get several runs in since a lot of folks will be up at the Gator Nationals ... of course, it's gonna' suck BAD if it's all ricers with no big slick cars so I can run in their groove.
It's been a while, but when I ran Yank 4L60E converters I found that foot braking up worked the best, but you should try 5-6 passes with nothing different than how you work with the converter. I'd try off idle up to whatever you can hold the car to with your brakes.
That's what I did with the Yank SS3600 I had. With the new PT4000, it's a lot different in it's behavior, as you know. I'm thinking it's gonna' rape the tires if I flash it from idle, or, if I stall it up too high.
I'll try it off idle and work my way up. Hopefully, I will be able get 3-4 runs in to see how it works leaving from different rpm's, as well. Once I get the 'driver mod' down, I'll start with tires at 20 psi and make individual changes like LCA relo bracket hole location. Once I find the position which works best, I'll start playing with the tire pressure.
Any advice is always welcome ...
I'll try it off idle and work my way up. Hopefully, I will be able get 3-4 runs in to see how it works leaving from different rpm's, as well. Once I get the 'driver mod' down, I'll start with tires at 20 psi and make individual changes like LCA relo bracket hole location. Once I find the position which works best, I'll start playing with the tire pressure.
Any advice is always welcome ...
Anybody else feel that 17-18 psi is too low? Always ran the Nitto's at a higher psi (20-22 hot) ... to avoid cupping at the center crown.
I'm going to try with 20 psi tonight in the MT DR's. No air pressure adjustments ... just want to see what rpm level the PT4000 likes off the tree, to see what works best. The lower pressure probably has been costing me about 1 mph ... more concerned about ET/60' times, though.
I'm going to try with 20 psi tonight in the MT DR's. No air pressure adjustments ... just want to see what rpm level the PT4000 likes off the tree, to see what works best. The lower pressure probably has been costing me about 1 mph ... more concerned about ET/60' times, though.
Last edited by JEB99TA; Mar 14, 2008 at 05:15 AM.