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fturner
11-01-2009, 06:31 PM
Went to the track today, with my new MT ET Streets :D. These are the bias ply ones that are 10.5 wide by 26 fitted onto a set of sc rims.

Best run
R/T - .487
60' - 1.997 :D
1/8 - 8.780
mph - 82.01
1/4 - 13.583 :D
mph - 102.63

Next best run
R/T - .453
60' - 2.046
1/8 - 8.848
mph - 81.54
1/4 - 13.661
mph - 102.28

I steadly improved as I got more and more used to the slicks and the way the car hooked up, and I'm developing a launching pattern so to speak that seems to work best with the current setup. My trap speed is way down from a best of 105.9mph but thoughts on that is because I'm not getting enough rpm at launch now that I used to get with spinning the street tires at launch.

Fraser

neverfastenough
11-01-2009, 06:32 PM
Doesnt this car have a different converter, whats the stall, lockup?

fturner
11-01-2009, 06:43 PM
Doesnt this car have a different converter, whats the stall, lockup?

Stock rebuild convertor with 2400 stall, and lockup. Still has the 3.27 gears in the rear.

Fraser

thunderkid84
11-01-2009, 08:28 PM
Fraser I noticed tha back in June u ran 14.1@98mph.

What have u done to the car since then to get a 13.5 ?

fturner
11-01-2009, 08:30 PM
At the end of June I installed the ported larger valved heads, and just recently I installed an MP inlet on the blower and up'd the OD to 15%.

Fraser

CMac89
11-01-2009, 10:28 PM
Put some gear in the damn thing, Fraser!!! JEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEE EEEZZZZZZ!!!

fturner
11-01-2009, 10:35 PM
Put some gear in the damn thing, Fraser!!! JEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEE EEEZZZZZZ!!!

Oh I intend to... its called a 5spd.

Fraser

neverfastenough
11-01-2009, 11:36 PM
You must drive like a man to go quicker with a 5spd frit. Give the stick guys a bad rep, and Ill drive up there and sneak an AOD back in.:p

Corey

Super Duper Cou
11-01-2009, 11:44 PM
Good job on the new fast time. :) I had a 1.997 60 ft at the track this past Wednesday on street tires in my super coupe but I only ran a 14.4 @ 94mph. lol

CMac89
11-01-2009, 11:54 PM
Oh I intend to... its called a 5spd.

Fraser
Yeeaahhhh, ya can't drive the car like a Canadian, thooooouuuuugh.

Good work, though. That's a good time. Traction will set you back in MPH.

fturner
11-02-2009, 09:53 AM
You guys kill me LOL! I grew up driving stick so they ain't a new thing to me ;)... and I know I can run my car faster with a stick than an AOD. As for the Canadian part, I do recall a certain Canadian handing people their collective butts with his 5 spd.

I just hope my knee holds together long enough for me to get a season out of it :(. My doc is already telling me not to head down that road, but hey, you only live twice :).

Fraser

neverfastenough
11-02-2009, 02:37 PM
So you are keeping the 3.27 with the 5spd?

fturner
11-02-2009, 02:47 PM
Time to put the thinking caps on and think this through. My car is bogging down with the slicks and only having a 2400 stall and stock gears. Now we know that putting in a higher stall like a 2800 and going with 3.55 gears would get my ET higher.... but in its current state there is room for improvement I think.

Looking at my datalogs, I noticed from the point of nailing the throttle at the first yellow light that it took the car .74 seconds to go from 700rpm idle to 2300 rpm's before the convertor started to stall... it took another .4 seconds to get to 2400's rpm's (this is a testiment to how accurate dirtydog can build a convertor to ;) ) and then rpm's stayed there, until I released the brakes to let the car go at green.

Taking into account the reaction time of an ole fart like me, the time it takes for the car to rev up to the stall point of the convertor and the .5 seconds between lights on the tree... I'm thinking if I nail the throttle on the second light and let the brake go between the 3rd yellow and green, that the engine will be still accelerating and I can take advantage of that to launch quicker because the energy needed to start the motor accelerating can instead be used to launch the car.

Also, the logs are showing my torque band seems to start right around 2800, as the engine acceleration is sluggish until then then it really accelerates.

The question is, will this improve my 60' and my ET... I'm going to try it out the next time I'm at the track, but I want folks to throw their ideas out there and then we'll see if the theory actually works.

BTW, datalogging what the car is doing from launch right to the top end can be a great asset to determining how to run the car at peak performance.

Fraser

fturner
11-02-2009, 02:47 PM
So you are keeping the 3.27 with the 5spd?

Nope, I have a 2.73 pumpkin going in.

Fraser

neverfastenough
11-02-2009, 02:53 PM
Good idea on the gears. SOOO, you are holding it against the converter at the start? Since youre switching anyway, you might want to just forget about the lights, and try different launches until you find the right one. I had a 2600stall DD in my car but never had a chance to get it to the track.:(

neverfastenough
11-02-2009, 02:58 PM
BTW you might not want to beat those tires up too much. I also run a 26in slick with 2.73 and trapping 104, my tach was around 5500. Its probably not accurate, but just a thought. I figure you make more power than me and will trap faster. You have H/C tho and your engine might like 5500rpm. I know mine quit making power at 4600 on the dyno recently. I think 28in might be a better option. However, Im only 280ish and with 2.73 and 28in, I might bog a bit much. Some fancy clutch work might fix that. You are also more ACT limited than me with your IC, so excessive rpm at the big end might not be a good thing for you. Im sure you thought about all this tho, its not your first rodeo.

fturner
11-02-2009, 03:03 PM
BTW you might not want to beat those tires up too much. I also run a 26in slick with 2.73 and trapping 104, my tach was around 5500. Its probably not accurate, but just a thought. I figure you make more power than me and will trap faster. You have H/C tho and your engine might like 5500rpm. I know mine quit making power at 4600 on the dyno recently. I think 28in might be a better option. However, Im only 280ish and with 2.73 and 28in, I might bog a bit much. Some fancy clutch work might fix that. You are also more ACT limited than me with your IC, so excessive rpm at the big end might not be a good thing for you. Im sure you thought about all this tho, its not your first rodeo.

From some testing I've done, and the way the valve train has been setup, the car should be good to 6000... if I went to a bit more duration with the cam then I can easily run it to 6500. Can't do that with the convertor I have so the car hasn't seen 6500 yet.

Fraser

neverfastenough
11-02-2009, 03:07 PM
From some testing I've done, and the way the valve train has been setup, the car should be good to 6000... if I went to a bit more duration with the cam then I can easily run it to 6500. Can't do that with the convertor I have so the car hasn't seen 6500 yet.

Fraser

Cool beans, should work out nicely.

Corey

David Neibert
11-02-2009, 09:02 PM
Went to the track today, with my new MT ET Streets :D. These are the bias ply ones that are 10.5 wide by 26 fitted onto a set of sc rims.

Best run
R/T - .487
60' - 1.997 :D
1/8 - 8.780
mph - 82.01
1/4 - 13.583 :D
mph - 102.63

Next best run
R/T - .453
60' - 2.046
1/8 - 8.848
mph - 81.54
1/4 - 13.661
mph - 102.28

I steadly improved as I got more and more used to the slicks and the way the car hooked up, and I'm developing a launching pattern so to speak that seems to work best with the current setup. My trap speed is way down from a best of 105.9mph but thoughts on that is because I'm not getting enough rpm at launch now that I used to get with spinning the street tires at launch.

Fraser

It's normal for mph to be lower when the tires hook up. Looser converter, or more rear gear would help the most. You can also try holding the throttle at 1300 rpms on the line and floor it from there while letting off the brakes at the same time to flash the converter a little higher.

Loading the converter all the way to stall is only something you would want to do if you were spinning the tires real bad and it doesn't sound like you are.

David

91bird
11-02-2009, 09:05 PM
Great run Fraser, looks like you have everything going in the right direction.

Drew

90blkbrd
11-04-2009, 09:12 AM
Loading the converter all the way to stall is only something you would want to do if you were spinning the tires real bad and it doesn't sound like you are.

I'm confused. I thought you should load the converter all the way up to stall and let her rip. If the tires spin then you should step it down in RPMS until you get traction. I did this at the shootout in Ken's car and got a 1.7x, the best 60 foot his car has ever done.

XR7 Dave
11-04-2009, 09:24 AM
I'm confused. I thought you should load the converter all the way up to stall and let her rip. If the tires spin then you should step it down in RPMS until you get traction. I did this at the shootout in Ken's car and got a 1.7x, the best 60 foot his car has ever done.

I would say that "personal experience" is the worst place from which to try to gain scientific proof of anything. There could have been 30 different factors that played into your "best 60 ft". In real racing one would never flash the converter from idle to get a higher stall speed because doing so will screw your reaction times up and make it impossible to really run consistently. In racing people generally choose the correct stall speed so that they don't have to pull tricks to get a good launch. It is conversely quite common for street cars to do all kinds of tricks to try to improve a launch. Just how effective one is vs. another is a matter of determining the weakest link as David alluded to. There are many factors - track prep, tire heat, suspension compliance, available torque, etc., that all affect initial bite and therefore the stall speed that will achieve maximum launch for any given set of "street car" parameters. Therefore don't just assume that what seems to "work" for one person is going to work for the next.

You all might want to ponder how it is that Dan McEwen manages to get 1.8 60fts on real street tires with his mid 13 second car.....

fturner
11-04-2009, 10:39 AM
I would say that "personal experience" is the worst place from which to try to gain scientific proof of anything. There could have been 30 different factors that played into your "best 60 ft". In real racing one would never flash the converter from idle to get a higher stall speed because doing so will screw your reaction times up and make it impossible to really run consistently. In racing people generally choose the correct stall speed so that they don't have to pull tricks to get a good launch. It is conversely quite common for street cars to do all kinds of tricks to try to improve a launch. Just how effective one is vs. another is a matter of determining the weakest link as David alluded to. There are many factors - track prep, tire heat, suspension compliance, available torque, etc., that all affect initial bite and therefore the stall speed that will achieve maximum launch for any given set of "street car" parameters. Therefore don't just assume that what seems to "work" for one person is going to work for the next.

You all might want to ponder how it is that Dan McEwen manages to get 1.8 60fts on real street tires with his mid 13 second car.....

Printing his own time slips out on an ole epson dot matrix printer :p:eek::D:p

Fraser

fturner
11-12-2009, 11:20 PM
Further study of my datalogs and discussing with Dave Dalke, the other thing that for sure killed my mph is the fact that almost every run started out with act's at 120 so timing was getting yanked as soon as I launched.

Before, no timing was getting yanked on the street tires because the car would just be tickling 120 at the top end.

Its the burnouts causing it, and line locks are going in the car so I don't hold the back brakes on while doing the burnout. Temps shouldn't go any where near the 120 I was getting before.... meanwhile, I'm heading to the track on Sat by the looks of it, and I'm going to try doing very short little 3 seconds burn outs just to clean the tires and see... not sure though if traction is going to be issue without some heat.

Fraser