Re: Foot brake or flash the converter?
[Re: 412 SB Duster]
#565647
12/30/09 02:37 PM
12/30/09 02:37 PM
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Joined: Nov 2009
Posts: 520 New Zealand
nz383man
OP
mopar
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OP
mopar
Joined: Nov 2009
Posts: 520
New Zealand
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Quote:
Ever try Q time pros they seem to work well when I ran them on the street, real soft compound.
I bought Quicktimes rather than Quicktime pro's because we are not allowed to run Quicktime pro's on the street in New Zealand & a couple of places we race are close enough to drive to on race tyres.
The best thing about a bad track is it's bad for everyone! I'm staarting to beat people on 1/8 miles that are concentrating on HP rather than hooking their car. For a factory stock car I hold my own OK on 1/8s but I don't have the charge for 1/4s.
Some of the late model Aussie sedans take some beating, the Holdens (307kw/411hp) & Falcons (317kw/425kw) go like hell & use traction control ![](/ubbthreads/images/graemlins/rant.gif)
DodgeCharger you wrote -
I would start working with rear tire pressure and loosen up the front of the car to get more weight transfer.
I'm running anything from 10-14psi I always run 14psi on the first run of a 1/4 to see how the car feels at the top end (remember roads, bumps, hollows etc) then they usually gain a couple of psi with heat so I drop down to 12psi (hot) & see how it runs. I take notes of every run I do. I really need to get in some decent testing at different pressures.
I'm running 275x50x15 Hoosier Quicktimes on 10" rims, would the sidewalls work better on a narrower rim? Hoosier say 8"-10" & 9" is best. I only use the 10" as they are what I could get, my car normally runs factory 14" Magnum 500s.
Any more ideas on loosening up the front? I have 318 torsion bars, Summit 90-10 shocks, factory length bump stops, factory bushes, joints etc
Thanks for the input everyone & keep it coming ![](/ubbthreads/images/graemlins/bow.gif)
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Re: Foot brake or flash the converter?
[Re: nz383man]
#565651
12/31/09 01:44 PM
12/31/09 01:44 PM
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Joined: Jul 2004
Posts: 19,318 State of confusion
Thumperdart
I Live Here
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I Live Here
Joined: Jul 2004
Posts: 19,318
State of confusion
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I`ve been beating/tweeking my car for years and my new combo which is a 470 bb stroker w/an 8" vert likes a 3000 rpm leave for the best 60ft/et. If you climb too far up in the r`s at the line you will start seperating the suspension and yes it is planting the tire somewhat but it`s also limiting the useable travel so whatever. I run 6-cyl bars but my car is lighter than yours and they work good for me on the street as some say they won`t. ![](/ubbthreads/images/graemlins/shruggy.gif) Too many variables......loosen the ft. as much as possible,play w/tire pressures launch etc. and the et`s will come. ![](/ubbthreads/images/graemlins/drumhit.gif)
Last edited by Thumperdart; 12/31/09 01:45 PM.
72 Dart 470 n/a BB stroker street car `THUMPER`...Check me out on FB Dominic Thumper for videos and lots of carb pics......760-900-3895.....
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Re: Foot brake or flash the converter?
[Re: Thumperdart]
#565652
12/31/09 04:11 PM
12/31/09 04:11 PM
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Joined: Aug 2003
Posts: 43,349 Bend,OR USA
Cab_Burge
I Win
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I Win
Joined: Aug 2003
Posts: 43,349
Bend,OR USA
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Every car and track are different so you have to experiment to find the best methods to use on your car, sorry that I can't give you the exact methods to make your car hook every time ![](/ubbthreads/images/graemlins/shruggy.gif) Don't forget that as the track gets more runs on it during the day that it may (probally) will change later in the day so what work in the morning may not be the best procedures to use in the race later in the day ![](/ubbthreads/images/graemlins/scope.gif) BTW, I had a 1970 Barracuda that I used to race in NHRA A/S, it had a hemi in it ![](/ubbthreads/images/graemlins/grin.gif) The weight distribution was very similar but worse than yours ![](/ubbthreads/images/graemlins/whistling.gif) 2160 lbs on the front and 1290 lbs on the rear with no driver and half a tank of fuel ![](/ubbthreads/images/graemlins/rant.gif) 4 speed on nine inch tires ![](/ubbthreads/images/graemlins/down.gif) As far as tire width and rims you might want to get a extra set of rims and drag race only slicks to use at the track only ![](/ubbthreads/images/graemlins/Twocents.gif) I have several sets of M/T ET Streets and ET Street Radails on ten inch and twelve inch rims. My car is a "street car" ![](/ubbthreads/images/graemlins/whistling.gif) that I built to race the high dollar street racers in Los Angles before I moved to Oregon ![](/ubbthreads/images/graemlins/tsk.gif) ( I never got to do that ![](/ubbthreads/images/graemlins/rant.gif) ) so I wanted it to look like a not so serious race car, hence the "street tires" The point I want to make is it will run the same ET and 60 ft. times leaving at 1200 rpm or at 2300 RPM, this is the first car(out of 12 or so automatic cars) that I have raced that is this way ![](/ubbthreads/images/graemlins/shruggy.gif) Most of the others like a higher stall,2300+RPM, especially the dedicated race cars with 8 or 9 inch converters. My current car has a custom built 10 inch converter, it has gone as fast as 10:43 at 128.9 MPH with that converter in the 1/4 and 6.86 in the 1/8, best 60 ft was 1.43 so far. The motor is a 518 C.I. pump gas (10.29 to 1 comp. ratio)low deck stroker in a 3450 lbs.1971 Duster with me in it with the 315x60x15 ET Street Radials on ten inch rims on the ladder bar rear suspension with coil overs. IHTHs , don't forget to test, test, and test some more.(write every change and the results down after every run, don't wait until the end of the day or the next day ![](/ubbthreads/images/graemlins/tsk.gif) ![](/ubbthreads/images/graemlins/luck.gif) Please keep us posted with your results ![](/ubbthreads/images/graemlins/thumbs.gif)
Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)
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Re: Foot brake or flash the converter?
[Re: Cab_Burge]
#565653
12/31/09 05:59 PM
12/31/09 05:59 PM
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Joined: Nov 2009
Posts: 520 New Zealand
nz383man
OP
mopar
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OP
mopar
Joined: Nov 2009
Posts: 520
New Zealand
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Cheers Guys, & Happy New Year, you are getting me very inspired to spend my holidays "Testing"
DodgeCharger “The tire might work better on a narrower rim. I never heard of a 275x50? only a 275x60.”
I'll keep my eyes open for some narrower rims. I went with the 275x50 as they have a 1" wider tread than the 275x60 & to keep the gearing lower.
Thumperdart “If you climb too far up in the r`s at the line you will start seperating the suspension and yes it is planting the tire somewhat but it`s also limiting the useable travel so whatever.”
OK, good call & I have a plan to check it, if use a remote tacho & a yard stick at each wheelarch I could video the rise relating to the revs on the converter in my garage, idle to 2600.
“Too many variables......loosen the ft. as much as possible,play w/tire pressures launch etc. and the et`s will come.”
I'll see what I can do with loosening the front, shorter bumpstops, research bushes etc. Would I be better to go to a pivot style joint on the track rods rather than the factory rubbers, as the rubbers do seem to limit movement a bit.
Cab_Burge “don't forget to test, test, and test some more.(write every change and the results down after every run, don't wait until the end of the day or the next day Please keep us posted with your results”
Yes, this is great advice & I do follow it. I would like to test more (who wouldn't) but I do take notes straight after every run & have pads of notes & excel spreadsheets that I refer back to all the time.
Some of you may thing I'm getting a bit carried away for such a slow car but I want to keep it factory stock looking but go as quick as I can. I am beating quite a few faster cars already on the 1/8 due to the fact I'm getting quite a bit of my power down rather that have more power & go up in smoke. I am collecting parts for a much stronger (stock looking) 383 so more power is the next goal.
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Re: Foot brake or flash the converter?
[Re: TS3303]
#565655
12/31/09 07:19 PM
12/31/09 07:19 PM
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Joined: Aug 2003
Posts: 4,055 Salina ks
572_dup2
Back On The Bumper!!
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Back On The Bumper!!
Joined: Aug 2003
Posts: 4,055
Salina ks
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My car has always seemed to leave its best around 2000-2200.
Shawn Jennings
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Re: Foot brake or flash the converter?
[Re: 572_dup2]
#565656
01/01/10 02:33 AM
01/01/10 02:33 AM
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Joined: Nov 2009
Posts: 520 New Zealand
nz383man
OP
mopar
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OP
mopar
Joined: Nov 2009
Posts: 520
New Zealand
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I tested the wheel arch height v RPM on the converter, sorry the heights are in mm but that was easier for my good lady to measure. ![](http://i611.photobucket.com/albums/tt196/383man_70/BodyHeightGraph.jpg) RPM LF RF LR RR Off 613 617 613 617 800 615 614 618 617 1000 615 614 618 618 1200 615 614 618 618 1400 620 610 620 615 1600 620 610 622 615 1800 622 606 625 612 2000 625 606 627 612 2200 626 603 629 610
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Re: Foot brake or flash the converter?
[Re: davenc]
#565662
01/03/10 10:08 PM
01/03/10 10:08 PM
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Joined: Nov 2009
Posts: 520 New Zealand
nz383man
OP
mopar
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OP
mopar
Joined: Nov 2009
Posts: 520
New Zealand
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Quote:
Caveat...I am no expert racer...
It looks like you are getting a fair amount of torque roll in the body when bringing up the RPM. If you can keep the back more even, you should get better traction. I don't think the 70 cuda had a rear roll bar option, but the later ones (72-74?) did. I'm curious if anyone else thinks that addition of a rear roll bar would help.
Dave
OK I'm curious what others think about a rear anti sway bar as well or should I go to SS springs? are the Mexican made SS springs any good or not?
Thumperdart
And that was my point about bringing the r`s up too much and seperating the suspension. That`s where a trans break comes in handy.......no suspension seperation and hits the tire harder although a t-brake is probably out of the question in your case. I foot brake my car but next time around I may go w/ a t-brake.
While out of town on holiday with my lady I did do a few flash the converter starts which showed the time I spent converting my Carter AVS to annular boosters was well worth the trouble.
The next time I race I'll do 2 or 3 runs footbraking to get a benchmark then try flashing the converter.
From the feedback I'm getting here I may need to footbrake where traction is bad & flash the converter where traction is good.
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