DragRaceResults.Com    Bracket Talk    Bracket Talk Forum  Hop To Forum Categories  Tech Talk - by Abruzzi    Alky and rear gear selection
Page 1 2 
Go
New
Find
Notify
Tools
Reply
  
Alky and rear gear selection
 Login/Join
 
DRR Top Comp
posted Hide Post
If I bracket race I'm def gonna shift 3 tenths after TB release. Unbelievable consistent. I highly suggest it small tire.
 
Posts: 9398 | Location: Madeira Beach Fl. | Registered: June 12, 2018Reply With QuoteReport This Post
DRR Trophy
posted Hide Post
My old set up would flash and ride that rpm before climbing up as you mentioned but my new combo flashes to 6300 and dips to 6000 before rpms climb. I haven't spoken to the converter builder yet but I'm curious what the rpm dip is an indication of, a little loose?
 
Posts: 4 | Location: Nc | Registered: August 11, 2017Reply With QuoteReport This Post
DRR Sportsman
posted Hide Post
I have run/tuned all 3 cars on gas, switched mine first to methanol, then later the other two. What I learned is that alky can change the engine's power characteristics, some cars might want more converter some might want less, some might tolerate more final gear, others less. Mine liked a little tighter converter and more gear, It liked it for consistency and another .1 was nice to see too. One of the other cars, very similar combo, wanted more gear (4.57 to 4.86) and it likes a spragless converter better than the sprag but it may have liked it better before switching to alky too, just never tried.

Trial and error is the correct way to know; and I think as you've seen already from the posts, everyone's stuff is a little different.
 
Posts: 540 | Location: central Ar | Registered: June 21, 2002Reply With QuoteReport This Post
DRR Top Comp
posted Hide Post
quote:
Originally posted by mavman:
I have run/tuned all 3 cars on gas, switched mine first to methanol, then later the other two. What I learned is that alky can change the engine's power characteristics, some cars might want more converter some might want less, some might tolerate more final gear, others less. Mine liked a little tighter converter and more gear, It liked it for consistency and another .1 was nice to see too. One of the other cars, very similar combo, wanted more gear (4.57 to 4.86) and it likes a spragless converter better than the sprag but it may have liked it better before switching to alky too, just never tried.

Trial and error is the correct way to know; and I think as you've seen already from the posts, everyone's stuff is a little different.


Which one is spragless, how do you distinguish?

 
Posts: 9398 | Location: Madeira Beach Fl. | Registered: June 12, 2018Reply With QuoteReport This Post
DRR S/Pro
Picture of banjo
posted Hide Post
So just giving an update,

I put the looser of my two converters in, flashes about 200 rpms different, but the manners are very different.

This one hits the converter flash, dips and proceeds to rise. Definitely hangs on the converter longer.

I am starting to get it figured out. Off the footbrake, I have had to raise my launch rpms approximately 1000 rpms to about 3900 to hit the tree. This is the thing that turned me off before about it. But I am finding i really like it. With this converter i am finding that my reaction time change vs rpm change is alot less. With the previous converter, 100 rpm difference would change reaction time .01 or more. No it seems that it on a few thousands. I can pretty easy footbrake it to 4500.

I have given up a few .01s in the sixty, but the bar has been raised on consistancy.

It feels very soft leaving. Before anything over 4000, the car would be iffy. But it takes a 5000 launch no problem, think I may try turning up the wick on that.

Definitely seems there is a bigger difference between the converters than stall speed.

It flashes to 6100, and I am shifting at 6800, going to play with that to see what it likes.

I am definitely glad I put this converter back in.


Bill Simpkins
74 Nova
SBC 406
3240 pounds
Speierracing heads

60 1.27 (10/16)
1/8 6.03@111 (10/16)
Best 9.87@131 on the rev limitor 1 Feb 2013


nova

quarterpanelview

wheelie

FTI Converter
www.speierracingheads.com

 
Posts: 1830 | Location: San Angelo | Registered: March 07, 2005Reply With QuoteReport This Post
DRR Pro
posted Hide Post
quote:
Originally posted by banjo:
I put the looser of my two converters in, flashes about 200 rpms different, but the manners are very different.

It flashes to 6100, and I am shifting at 6800, going to play with that to see what it likes.


If you shift at 6800 , what rpm does the shift complete at? Given your sbc hp, to me if you are not seeing at least 7000 at shift completion, the fall back rpm could be closer to the stall after it is completed.

As the convertor becomes looser, at some point this fall back to stall becomes much closer. This is where I was at with my old convertor and the new one I installed recently has moved this back to a slightly larger rpm spread between stall and fall back.

Not saying one way is more right than other, just saying what I want in my run.
 
Posts: 2527 | Location: 53056 | Registered: December 30, 2009Reply With QuoteReport This Post
DRR S/Pro
Picture of banjo
posted Hide Post
The logger shows it's about 6850, but for some reason, my logger rounds the point at were it shifts, so I would suspect it's a little higher.


Bill Simpkins
74 Nova
SBC 406
3240 pounds
Speierracing heads

60 1.27 (10/16)
1/8 6.03@111 (10/16)
Best 9.87@131 on the rev limitor 1 Feb 2013


nova

quarterpanelview

wheelie

FTI Converter
www.speierracingheads.com

 
Posts: 1830 | Location: San Angelo | Registered: March 07, 2005Reply With QuoteReport This Post



  Powered by Social Strata Page 1 2  
 

DragRaceResults.Com    Bracket Talk    Bracket Talk Forum  Hop To Forum Categories  Tech Talk - by Abruzzi    Alky and rear gear selection

© DragRaceResults.com 2024