rear gears, stall speed, and street/strip A - Page 2 - Hot Rod Forum : Hotrodders Bulletin Board
Hotrodders.com -- Hot Rod Forum



Register FAQ Search Today's Posts Unanswered Posts Auto Escrow Insurance Auto Loans
Hot Rod Forum : Hotrodders Bulletin Board > Tech Help> Transmission - Rearend
User Name
Password
lost password?   |   register now

Reply
 
LinkBack Thread Tools
  #16 (permalink)  
Old 03-18-2011, 12:06 PM
F-BIRD'88's Avatar
Yada Yada Yada
 
Last photo:
Join Date: Oct 2005
Location: Ontario, Canada
Posts: 9,547
Wiki Edits: 0

Thanks: 3
Thanked 331 Times in 328 Posts
The fact that the motor peaked at 6000 and nose dived at 6300 rpm indicates that something is wrong. Cam, springs, carbs ignition, very restricted heads or exhaust.

You are making assumptions on the converter, how it works and the right converter/gear/tire combo functions at highway speeds. If the car was geared right it would cruise fine on the hiway with a decent converter stall.
Its all abut matching the gear and the converter to the job.

Reguardless of the stall you do not load the engine rpm up against the brakes at the start line.
This staging method slows the car.

Launch at or near idle speed. This maximises the torque multiplication function of the converter at launch as the converter "flashes"

Get a real 9"-- 10" converter. 3500 stall or better, get the gear that works with the tires and fix the motor.
You need to fix what is limiting the motor now (RPM), before exploring more blower boost. Something is not right.
(the cam is actually small for this combo and hyd rollers suck in general.
You can fix it.

You need to shift at +++6000 rpm I suggest 6500 rpm. Fix the valvetrain so it will function to 6700rpm. ( Better cam, , premimum high rpm light hyd roller lifters, better springs, AFR hydra rev rev kit. Or ditch it for a solid flat tappet or solid street roller setup.

Blower motors like to rev.

What street tires are you using? How tall? This motor will be perfectly confortable cruising at 60MPH at 3200 rpm and a good 9"-10" converter with a 3600 to 4200 stall will function fine and stay cool.

Your street tires should be as tall or taller than your slicks for a dual purpose car.

Don;t bother with a manual valve body. It will not make you go faster. It is much harder on a street th-350. I'd, infact set up the auto valve body to auto-shift at -6300-6500 rpm WOT in "D" So you can race in "D".
You'll go faster.

    Advertisement

Last edited by F-BIRD'88; 03-18-2011 at 12:18 PM.
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
  #17 (permalink)  
Old 03-18-2011, 03:21 PM
ericnova72's Avatar
More for Less Racer
 
Join Date: Jan 2007
Location: S.W. Lower Michigan
Age: 47
Posts: 8,915
Wiki Edits: 0

Thanks: 19
Thanked 364 Times in 334 Posts
Quote:
Originally Posted by cobalt327
Given the drop off after 6K RPM, you might want to shift closer to 6K than that.

Given 118 MPH, 3.54 gears and 26" tires (is this what they are?), the trap RPM (w/o TC slip) will be almost 5500 RPM (120.18 MPH = 5500 RPM, w/o slip).

You mentioned the shift light set at 5500 RPM is lit as you go through the lights. If your tires are larger diameter than 26", this indicates excessive slippage of the TC.
He has excessive slip, first posts lists a 30" tire while racing it. Typical B&M off the shelf converter.

Needs a good tight 9-10" converter, around 4000 stall...and to the OP, no it won't slip like crazy and make heat on the highway if you get a good one made for the job....that "slip like crazy on the road" crap all the car magazines have been polluting people's mind with is just bull. Sure it was true with an air-cooled stock Vega converter behind a V8 in the 70's, but is not true today at all. Converter technology has come a long way.
Reply With Quote Quick reply to this message
  #18 (permalink)  
Old 03-18-2011, 07:26 PM
471A
 
Last photo:
Join Date: Jun 2008
Location: Oregon
Posts: 148
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Any recommendations on a convertor manufacturer who does custom work. Coan ? Fairbanks ? Race season is now starting in Oregon so I would appreciate a converter builder who could provide the 4,000 stall that several have recommended. I also am thinking of 4.10 gears in my Dana 60. Any higher than that is likely to become annoying in the "street" past of this 29 Tudor's life, particularly on 100 mile freeway runs. Finally, any thoughts about converting the current B & M TH 350 to a manual valve body ?
Reply With Quote Quick reply to this message
  #19 (permalink)  
Old 03-18-2011, 08:09 PM
cobalt327's Avatar
WFO
 
Last wiki edit: Intake manifold
Last journal entry: 1980 Malibu Wagon
Last photo:
Join Date: Mar 2009
Location: Atlanta
Age: 59
Posts: 5,037
Wiki Edits: 1616

Thanks: 128
Thanked 597 Times in 546 Posts
Quote:
Originally Posted by ericnova72
...first posts lists a 30" tire
So like I said- excessive slippage- to the tune of ~ 15%.

Quote:
Originally Posted by cobalt
A looser TC is a given in your case. A decent compromise would be a "tight" 10".
Quote:
Originally Posted by cobalt
If your tires are larger diameter than 26", this indicates excessive slippage of the TC.
Reply With Quote Quick reply to this message
  #20 (permalink)  
Old 03-18-2011, 09:34 PM
F-BIRD'88's Avatar
Yada Yada Yada
 
Last photo:
Join Date: Oct 2005
Location: Ontario, Canada
Posts: 9,547
Wiki Edits: 0

Thanks: 3
Thanked 331 Times in 328 Posts
Quote:
Originally Posted by 471A
Any recommendations on a convertor manufacturer who does custom work. Coan ? Fairbanks ? Race season is now starting in Oregon so I would appreciate a converter builder who could provide the 4,000 stall that several have recommended. I also am thinking of 4.10 gears in my Dana 60. Any higher than that is likely to become annoying in the "street" past of this 29 Tudor's life, particularly on 100 mile freeway runs. Finally, any thoughts about converting the current B & M TH 350 to a manual valve body ?
You won;t go any faster with a full manual valve body. It causes the transmission shift pressure to be balls out all the time even at part throttle and downshifting. This is very hard on the life of the transmission.

If you want to run 4.10's get shorter strip tires and taller street tires.

If you had the right gear-tire combo your B&M converter you have now, would not "slip" so much. (based on MPH and trap RPM)

The car should trap at 4 to 8% higher than the peak HP RPM point.
When the gear is right, the converter performs best with the least "slip".

When the gearing is wrong the converter is too loaded and will tend to have too much slip loss based on the math.

Again, the motor will be quite happy reving 3200 rpm on the hyway.
Its a high performance motor, it wants to "rev".

There are many good custom torque converter companies.

Coan, Neal Chance, ATI, to name a few.

Do you have a engine dyno test sheet printout showing Horsepower, torque and Blower boost/rpm?

Post a few of your past Drag ET slip numbers.

60ft, 1/8th et and MPH 1/4 et and MPH.
Reply With Quote Quick reply to this message
  #21 (permalink)  
Old 03-21-2011, 09:32 PM
471A
 
Last photo:
Join Date: Jun 2008
Location: Oregon
Posts: 148
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
My shift light - set at 5,500 rpm - lights up as I near the stripe at the big end. The current rear tires are 30.0 x 9.0 x 15 Goodyear drag radials. So based on the input - superb as usual from those who post on HRB - my current plan is as follows: install a 3,500 stall convertor custom built for my combination, bump the shift points to 6,000-6,200 (try both; choose which one is lower e.t.), install 3.73 gears in the Dana 60, switch the rear radial slicks to not more than 28 inch diameter, and then ..........see what happens. To all who contributed, "Thank You". And "Yes", as race season dries out and opens here in Oregon, I will post results as the experiment continues. Whether or not the A runs 10.99 or quicker, the info learned in this exchange has been valuable and enjoyable. And a final word: I understand that this combination would run at least as quick, and maybe quicker, by adjusting the automatic shift points and racing only in Drive. But the bottom line for me is fun, not winning races, and shifting off the light while accelerating down the track is second only to the launch as pure fun !
Reply With Quote Quick reply to this message
  #22 (permalink)  
Old 03-21-2011, 09:44 PM
471A
 
Last photo:
Join Date: Jun 2008
Location: Oregon
Posts: 148
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
As a footnote, the last three quarter-mile time slips from 2010 - with the current combination of 3.54 gears-30 X 9 X 15 tires - 2,800 stall convertor-and shifting at 5,500 were as follows:

(1) 11.23 e.t./ 117.78 mph/1.614 60 ft. 1/8th: 7.115 e.t./mph 96.96

(2) 11.295 e.t./116.61mph/1.625 60 ft. 1/8th: 7.148 e.t./mph 96.77

(3) 11.379 e.t./116.18mph/1.649 60 ft. 1/8th: 7.194 e.t./95.27

Runs (1) and (2) were made shifting at 5,500 off the light. Run (3) was made in Drive.
Reply With Quote Quick reply to this message
  #23 (permalink)  
Old 03-22-2011, 03:55 AM
cobalt327's Avatar
WFO
 
Last wiki edit: Intake manifold
Last journal entry: 1980 Malibu Wagon
Last photo:
Join Date: Mar 2009
Location: Atlanta
Age: 59
Posts: 5,037
Wiki Edits: 1616

Thanks: 128
Thanked 597 Times in 546 Posts
I believe your sub-11 second run is in the bag using the changes you've outlined.

I'd be curious to know if just changing shift points would get you into the tens w/the set up the way it now is.

Good luck and thanks for supplying good info for the board to work with and for keeping us posted on what happens.
Reply With Quote Quick reply to this message
  #24 (permalink)  
Old 03-22-2011, 09:23 AM
sqzbox's Avatar
My pipes are my music
 
Last photo:
Join Date: Sep 2009
Location: indiana
Age: 64
Posts: 2,938
Wiki Edits: 0

Thanks: 0
Thanked 1 Time in 1 Post
Quote:
Originally Posted by 471A
My shift light - set at 5,500 rpm - lights up as I near the stripe at the big end.
DOES THIS MEAN YOU'RE CROSSING THE LINE IN SECOND GEAR ?
Reply With Quote Quick reply to this message
  #25 (permalink)  
Old 03-22-2011, 10:36 PM
471A
 
Last photo:
Join Date: Jun 2008
Location: Oregon
Posts: 148
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
With the TH 350 and 3.54 rear gears, the A crosses the quarter-mile stripe in 3rd gear, whether in drive or with me shifting 1-2 and 2-3 off of the current 5,500 shift light. While I cannot say for certain exactly where on any individual pass I am making the 2-3 shift, my recollection is that the 2-3 shift comes past the 1/8th and before the 1,000 foot. Based upon the HRB input, I now plan to shift at 6,000-6,2000 as race season begins in soggy Spring western Oregon.
Reply With Quote Quick reply to this message
  #26 (permalink)  
Old 03-22-2011, 11:55 PM
ericnova72's Avatar
More for Less Racer
 
Join Date: Jan 2007
Location: S.W. Lower Michigan
Age: 47
Posts: 8,915
Wiki Edits: 0

Thanks: 19
Thanked 364 Times in 334 Posts
If you are in 3rd gear then that is showing 1000+ rpm slip in the converter with the current combination. That's excessive.
Reply With Quote Quick reply to this message
  #27 (permalink)  
Old 06-26-2011, 10:41 PM
471A
 
Last photo:
Join Date: Jun 2008
Location: Oregon
Posts: 148
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
My 29 A was short one part (a locking dip transmission dipstick) to permissibly run 10.99 or quicker at this weekend's 35th annual Oldies but Goodies drags at the Woodburn, Oregon strip. Running 15 pounds on the Goodyear Eagle radial slicks, which I bolted on after driving to the track, I set the shift light to flash at 5,200, well below the HP peak of 6k. The result: back to back e.t.s of 11.029 and 11.007, each with 1.58 60 foots, and 119 mph. Once I bolt in the required dip stick, and adjust the shift points upwards closer to 6k, this 29 will run 10.99 and under. "Thank You", very much to Cobalt, FBird, EricNova, and others who offered in March advice that I put to use in getting this street/strip steel Tudor on the verge of running 10s. When it does, I will post again. Again, "Thanks".
Reply With Quote Quick reply to this message
  #28 (permalink)  
Old 06-27-2011, 04:27 PM
ericnova72's Avatar
More for Less Racer
 
Join Date: Jan 2007
Location: S.W. Lower Michigan
Age: 47
Posts: 8,915
Wiki Edits: 0

Thanks: 19
Thanked 364 Times in 334 Posts
Quote:
Originally Posted by 471A
My 29 A was short one part (a locking dip transmission dipstick) to permissibly run 10.99 or quicker at this weekend's 35th annual Oldies but Goodies drags at the Woodburn, Oregon strip. Running 15 pounds on the Goodyear Eagle radial slicks, which I bolted on after driving to the track, I set the shift light to flash at 5,200, well below the HP peak of 6k. The result: back to back e.t.s of 11.029 and 11.007, each with 1.58 60 foots, and 119 mph. Once I bolt in the required dip stick, and adjust the shift points upwards closer to 6k, this 29 will run 10.99 and under. "Thank You", very much to Cobalt, FBird, EricNova, and others who offered in March advice that I put to use in getting this street/strip steel Tudor on the verge of running 10s. When it does, I will post again. Again, "Thanks".
Cool Beans!!!

What were the exact changes you made, if you don't mind my asking??
Reply With Quote Quick reply to this message
  #29 (permalink)  
Old 06-27-2011, 08:23 PM
471A
 
Last photo:
Join Date: Jun 2008
Location: Oregon
Posts: 148
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
While I still plan to go to a 10 inch, 3,500 stall convertor, the weekend's 11.007 and 11.029 e.t.s, and 1.58 60 ft, were run with the same B & M 2,800-3,000 off-the-shelf convertor noted in my earlier March 2011 posting. First thing I changed, advised by FBird, was to stop trying to load the convertor at the tree by taking the rpms as high as I could before the car would begin to creep into the lights. Instead, as FBird advised, I left at idle, going to WOT off the last amber. Second, after rolling through the water box, and been given the burnout signal, I would spin the Goodyear Eagles, set at 15 pounds, until the A would pitch left, which typically took 4-5 seconds. This helped create the 1.58 60 ft times. (A week earlier, I tried BFG street-strip radial T/As, and had a pathetic cumulative 60 foot times of 1.96, 2.02, 2.03, and 2.05.)) Third, I ran 114 race gas, allowing me to run WOT locked at 36 degrees advance. On the street, again advised by FBird, I back out one degree of timing for every pound of boost, using an MSD boost timing master. Referring back to my earlier postings, the parts and tuning described in those early postings remain unchanged, including the boost referenced Holley 600s, the 31 inch Goodyear Eagles, the B & M convertor, and the rear gears of 3.54.
Reply With Quote Quick reply to this message
  #30 (permalink)  
Old 08-13-2011, 06:25 PM
471A
 
Last photo:
Join Date: Jun 2008
Location: Oregon
Posts: 148
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Today, at Woodburn, Oregon dragstrip, my 29 A Tudor ran 10.93 @ 120.83 mph with a 1.55 60 ft. "Thank you hugely" to FBird88, Cobalt327, Deuce, AutoGear, ericnova72, and sqzbox, each of whom posted on my June 2011 request for advice on running a "10" in my SBC blown SBC street rod. Back in June, based on the advice of those just listed, I changed shift points to 5,600 and, instead of powerbraking against the convertor, simply staged at idle, then flashed the convertor with WOT on the last amber. Result: these two simple driving changes moved the best e.t. down from 11.23 to back-to-back 11.023 and 11.007. Away from the track for spine reasons until this weekend, I used the away-time to install a 4,000 stall ten inch A-1 convertor, custom built by this well-respected Vancouver, Washington convertor builder. The switch, also advised by FBird et al. was the final step in running today's 10.93. Congratulations to the collected HBB crew chiefs !!
Reply With Quote Quick reply to this message

Recent Transmission - Rearend posts with photos

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the Hot Rod Forum : Hotrodders Bulletin Board forums, you must first register.
Please enter your desired user name (usually not your first and last name), your email address and other required details in the form below.
User Name:
If you do not want to register, fill this field only and the name will be used as user name for your post.
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.




Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools

Posting Rules
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
Rear End for street/strip Fnix Transmission - Rearend 6 11-07-2008 10:27 AM
Front Disc/rear Drums on street strip car cujoe822 Suspension - Brakes - Steering 2 09-07-2006 07:32 PM
Best tranny and gears for street/strip 420HP/550HP 2200LB Car? V8Guy427 Transmission - Rearend 1 01-23-2004 03:15 AM
Steet and Strip stall speed? MuscleBlock81 Engine 16 10-30-2003 07:19 PM
Rear gears to use with a 3000 stall dion Transmission - Rearend 1 06-01-2003 09:43 PM


All times are GMT -6. The time now is 10:05 AM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0 PL2
Copyright Hotrodders.com 1999 - 2012. All Rights Reserved.