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Discussion Starter #1
I only got to make one pass at our local track on Saturday before getting booted. I was on bald BFG drag radials at 17 psi of tire pressure. The boost was at about 28 psi. Here's how it breaks down:

60' 1.857
330' 4.907
1/8 7.316
MPH 102.44
1000 9.375
1/4 11.118
MPH 128.71

Does this all look ok? I was a little concerned that I only picked up about 26 MPH in the last 1/8 mile. That was with the TC locked up.

Maybe it's my imagination. I thought I should be trapping a little higher, or picking up more than 26 mph in the last 1/8 mile. If it looks normal, cool.
 

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Hey, I'm not sure either if there is something wrong with your timeslip or not. But, NICE RUN!!! :D I was just wanting to know about your rims. Did you run that time on those rims? They look more like 18" rims, which wouldn't fit the drag radials. or did you use the stock rims with 275/40/17 bfg d/r ??
 

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Time wise You're OK with that 60' but you should be running a higher MPH for what you dyno'd and when comparing to a car (Mark Cooper's) with a similiar setup except that he was on E/T streets on this run

BTW... he's ran a 10.3 on BFG DR's

 
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The 1/4 MPH is a little low but MADMKIV why would that have anyhting to do with his 60'? Anyway, 128 is a little low for 102 in the 1/8, your TC slipping? Tranny slipping? Good luck
 

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Did I explain it wrong or did you read it wrong? I said that his ET is decent for his 60' but that his MPH looks low IMO when compared to a similiar car.


Brad Mayo said:
The 1/4 MPH is a little low but MADMKIV why would that have anyhting to do with his 60'? Anyway, 128 is a little low for 102 in the 1/8, your TC slipping? Tranny slipping? Good luck
 
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Discussion Starter #6
BoostedTT,

You are correct. The rims in my signature are 18's. I run the stock 17" rear rims with my drag radials at the track.

MadMKIV,

Thanks for posting Coop's slip. He's a launching machine. He rips 1.5's and 1.6's on drag radials. I haven't mastered that yet. Especially when I only get one pass per trip to the track.

What I was really looking at was to see what kind of MPH he picked up in the last 1/8 mile. It seems like the faster you're going in the first 1/8, the less mph you pick up in the last 1/8. I used to pick up closer to 30 mph, but I never broke 100 mph in the 1/8 before. It looks like he only gained about 26.8 mph in the last 1/8 (which is about what I did) So maybe that's normal.

By the way, Coop has the .81 housing and runs a touch more boost than I do. That might explain the extra 4.2 mph through the traps. Thanks for posting the time slip.
 
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Discussion Starter #7
Brad Mayo said:
Anyway, 128 is a little low for 102 in the 1/8, your TC slipping? Tranny slipping? Good luck
See, that's kind of what I was thinking. That's why I posted. The TC is brand new (after I trashed it once, they rebuilt it for free), so I don't think that's it. I don't know how I could really test it anyway.

I certainly hope it isn't my tranny slipping. It feels fine, but I guess it's possible that the 3rd gear clutches are getting tired. The shifts are still crisp, no hang ups, no hitting rev limiter. Nothing seems like its slipping. If I didn't see the timeslip, I'd never have known that anything was "wrong".

Any other opinions?
 
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Discussion Starter #9
Wrong??

Nothing seems "wrong" to me...........


You ran a 11.1 at 128mph with a ~1.9 60'!!!!!!!!

I hate to bench race, but lets say you pulled a 60' like Coop 1.5. Assuming every .1 on the 60' is .2 on the 1/4--that makes your slip-- 10.3 at 128mph!! which is very close to Marks #!!!! The last 4mph can be from a ton of variables(temp, tailwind) Not to mention that Mark runs an 0.81 a/r and ran with more boost. This would/should give him more HP, hence more mph.

Remember 128mph vs 132mph is only a 3% difference and not really significant considering all the other variable that aren't accounted for.


P.S.--good run!!
 
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Re: Wrong??

BLK-SP64 said:
Nothing seems "wrong" to me...........


You ran a 11.1 at 128mph with a ~1.9 60'!!!!!!!!

I hate to bench race, but lets say you pulled a 60' like Coop 1.5. Assuming every .1 on the 60' is .2 on the 1/4--that makes your slip-- 10.3 at 128mph!! which is very close to Marks #!!!! The last 4mph can be from a ton of variables(temp, tailwind) Not to mention that Mark runs an 0.81 a/r and ran with more boost. This would/should give him more HP, hence more mph.

Remember 128mph vs 132mph is only a 3% difference and not really significant considering all the other variable that aren't accounted for.


P.S.--good run!!
Thanks. Just wanted to make sure everything looked normal to everyone else.
 
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Discussion Starter #11
FYI,
When Cooper tried out the .70 housing on the SP63 he ran ~130mph in the traps, and around 10.3-10.4's on radials. These were with consistent 1.6 - 1.70 60fts.

He lost 3mph but not much in ET.

-Roberto
 
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Discussion Starter #12
Stage7 said:
FYI,
When Cooper tried out the .70 housing on the SP63 he ran ~130mph in the traps, and around 10.3-10.4's on radials. These were with consistent 1.6 - 1.70 60fts.

He lost 3mph but not much in ET.

-Roberto
Roberto,

What I'm most interested in is the difference between the MPH at the 1/8 mile and the MPH at the end of the 1/4 mile. I want to make sure that picking up 26.5 MPH is "average" or acceptable. It seems like I used to pick up closer to 30 mph between the 1/8 and the 1/4, but I wasn't going as fast at the 1/8 as I am now. I guess what I'm trying to determine is whether or not it's possible that my tranny or TC is slipping or if my MPH is normal.

What do your time slips look like in terms of MPH at the 1/8 and at the 1/4? Thanks, Mark
 
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Discussion Starter #13
I see your point. Most Supra's are picking up ~30mph the last 1/8th, even some stock twin guys. But I do know 1 thing that might make you feel a liitle better. Larry's Famous 9.52 sec run; he had 114mph in the 1/8th and 144mph in the 1/4 mile with a bigger turbo, bigger a/r and NOS!!! I realize it doesn't explain anything but it would make me feel better. How are your traps when you get horrible 1/8th miile times?
 
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Discussion Starter #14
BLK-SP64 said:
I see your point. Most Supra's are picking up ~30mph the last 1/8th, even some stock twin guys. But I do know 1 thing that might make you feel a liitle better. Larry's Famous 9.52 sec run; he had 114mph in the 1/8th and 144mph in the 1/4 mile with a bigger turbo, bigger a/r and NOS!!! I realize it doesn't explain anything but it would make me feel better. How are your traps when you get horrible 1/8th miile times?
It seemed like when I was running 93-98 mph 1/8 mile speeds, I was picking closer to 30 mph. 93 mph in the 1/8 would definitely get me 30 mph more by the quarter. 98 mph in the 1/8 would usually get me another 28-29 mph by the quarter. Now that I'm running over 100 mph in the 1/8, I'm only picking up 26.5 mph by the quarter.

Here's the thing. I don't know if the difference in mph between the 1/8 and the 1/4 is because of the speeds in the first 1/8 or because the tranny now has a LOT more passes on it. That's what I'm concerned about. I'd like to think that because I'm going faster in the first 1/8, I'm not picking up as much in the last 1/8. I'd be really bummed out if the reason I'm not picking up the MPH is because my tranny is getting "tired". Does that make sense?
 
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Discussion Starter #16
flip said:
Sort of off-topic, but where did you make this pass?

Chris (Wichita)
Kansas City International Raceway. 8201 Noland Road, KCMO.
 
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Discussion Starter #18
RSA Supra said:
Very Nice Run, but I wouldn't be suprised if your Level 10 tranny was slipping. But who knows. How often do you change your fluid and does it still look red, or does in look all brown and full of clutch material?
I change the tranny fluid everytime I change the oil, which is about every 1000 miles or so. We had the whole tranny pan off the car back in October because we thought the trans was slipping. There was no material on the magnets. Turns out, I broke most of the fins in the TC so PI rebuilt it for me.

I also have a decent tranny cooler on there. I take EXTREMELY good care of that trans, but that doesn't mean that it's not giving out just because of wear and tear.

Looking at Mark Cooper's time slip, it looks like he's only picking up about 26.5 mph in the last 1/8 mile, too. I'm just trying to convince myself that it's ok. I've got to drop the trans next weekend anyway because my front pump seal is leaking. I was contemplating whether or not to have the tranny "freshened up" while it was out of the car, or just slap the new seal in it and put it back in and hope for the best.
 
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Discussion Starter #19
completely unacceptable !!!!

Mark, I think that you need to just convert the car to N/A and then "donate" your motor and trans. to me for the 85' MKII beater that I just bought, and call it a day. But thats just my opinion......
Anyways that seems like an awesome run to me, now you just need to get that pig out of the hole a little better.

Later,

Chris K.

1985 Maroon/Rust P type with 300K !
It's the poor man's supra !!!!!!
 

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2DVS4U said:


I change the tranny fluid everytime I change the oil, which is about every 1000 miles or so. We had the whole tranny pan off the car back in October because we thought the trans was slipping. There was no material on the magnets. Turns out, I broke most of the fins in the TC so PI rebuilt it for me.

I also have a decent tranny cooler on there. I take EXTREMELY good care of that trans, but that doesn't mean that it's not giving out just because of wear and tear.

Looking at Mark Cooper's time slip, it looks like he's only picking up about 26.5 mph in the last 1/8 mile, too. I'm just trying to convince myself that it's ok. I've got to drop the trans next weekend anyway because my front pump seal is leaking. I was contemplating whether or not to have the tranny "freshened up" while it was out of the car, or just slap the new seal in it and put it back in and hope for the best.
I think you've found the culprit.

If your front pump seal is leaking, then you're probably not getting enough line pressure to the tranny. Thats often what causes a tranny to fail.

Get it repaired and if its already been built up, some new clutches shouldn't be a whole lot of money to put in and make sure to change the tranny filter too.

God Luck!
 
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