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-   -   gear or converter (https://classracer.com/classforum/showthread.php?t=40184)

Steve Hayward 04-13-2012 01:42 PM

Re: gear or converter
 
Aside from addressing larger tasks in that combo......... It would cost nothing to borrow some smaller carbs and see if that helps............

Phillip marvetz 04-16-2012 03:35 AM

Re: gear or converter
 
Quote:

Originally Posted by slwryde (Post 321220)
I am turning 6900 rpm. I could probably afford to turn it a little higher say 7500 rpm.

You could go another 1000 on the stall rpm. Changing to a lower 1st will mask that a bit also. The carb is to small for a 414 cu engine tuning 7000rpm also.

HP HUNTER 04-16-2012 10:06 AM

Re: gear or converter
 
Quote:

Originally Posted by slwryde (Post 321145)
My car is a little lazy of the line. I have a 414 sbc. 1.76 powerglide. 14-32 slicks. Rear gear 5.13. 60 foot times range 1.52 to1.55. My converter stalls instantly to 4500 on the brake and creeps up to about 5000.

Again it leaves lazy, I think. I would like opinions on weather a rear gear change (deeper), a converter change (looser) or a lower tranny gear would be best.

thanks Greg.

Im a little hesitant to ask, but who's converter do you have in there? With that kind of power 1.3s 60s should be no problem if everything is right, even with the glide. Did you ever weigh the converter empty of fluid?

slwryde 04-16-2012 09:43 PM

Re: gear or converter
 
I used to run a 1.82 first gear, it was worth a few numbers but I was afraid I would break it eventually. My carb is an older style 850, I have tried a smaller carb 750 holley hp. It seemed more responsive but the et's and 60's did not change. I never thought of going larger than 850 but it would be worth a try.

The converter is from Chance. I told Marty about the hesitation to reach full stall and he suggested adjusting the timing. I never weighed it empty. What should I be looking for there? Thank you for the help.

Geerhead55 04-17-2012 12:19 AM

Re: gear or converter
 
We put a 13.5 to1 406 with some 220 heads and a Comp roller (276-284/ 630- 672) on the dyno a few weeks back, and with an 850 Dp it made 605 after playing with it a little. We then threw on a 950 DP that was supposedly "really good" and lost 18 hp. Since it wasn't my carb, I didn't want to mess with it, so I pulled it. I told our dyno guy that I had a 750 that we could try, and he didn't think it would do any good on a 406 like this unless it was really tweaked on. I showed him it was a Proform bodied unit that had been worked over pretty well, so he said go ahead and try it.
Right away you could hear the difference in the way it idled, and it accelerated much quicker on that next pull, all the way to 7500 and it made 625hp!
I pulled the 82 jets from the secondaries and went to 84s where it lost 12 hp, so we put the 82s back in and it repeated to 623 hp.
So, when we first hit the track soon, it will be with the 750, although I'm sure there will be other carbs in the future.
Danny Durham

HP HUNTER 04-17-2012 08:37 AM

Re: gear or converter
 
Quote:

Originally Posted by slwryde (Post 321870)
I used to run a 1.82 first gear, it was worth a few numbers but I was afraid I would break it eventually. My carb is an older style 850, I have tried a smaller carb 750 holley hp. It seemed more responsive but the et's and 60's did not change. I never thought of going larger than 850 but it would be worth a try.

The converter is from Chance. I told Marty about the hesitation to reach full stall and he suggested adjusting the timing. I never weighed it empty. What should I be looking for there? Thank you for the help.

I cant stress enough the importance of a good converter, I believe this is where your problem originates from, get with the right people on this, Ultimate, or ATI. In my opinion theres only one core to use when building an 8 inch converter, ATI went out and made a copy of it, that should tell you something. "The converter is from Chance. I told Marty about the hesitation to reach full stall and he suggested adjusting the timing." This sounds like something Jim Hughes would tell one of his customers. LOL

Phillip marvetz 04-17-2012 05:52 PM

Re: gear or converter
 
Quote:

Originally Posted by HP HUNTER (Post 321923)
I told Marty about the hesitation to reach full stall and he suggested adjusting the timing." This sounds like something Jim Hughes would tell one of his customers. LOL


My Hemi car with Turbo Action J converter does that also. Someday it will get a new ATI.

slwryde 04-17-2012 10:47 PM

Re: gear or converter
 
Well I guess you have to start somewhere. I ordered a new 3rd member with 5.43 gears. I figure this will at least improve the starting line ratio. I think it may make the converter "act a little tighter". If this does not help I will spend some $$ on a converter.

Geerhead55 04-17-2012 10:59 PM

Re: gear or converter
 
After the dyno session, I called ATI and talked to John,, gave him the info he needed, including the dyno numbers and new converter got here last week, can't wait to try it out.
As far as converter cores, the story I heard was that ATI got the cores and the dies to make them from GM after they stopped Opel production years ago, so I don't know about any "copying" going on. I'm sure someone on here is closer to the story and can elaborate on it. Good luck with your project.
Danny Durham

HP HUNTER 04-17-2012 11:09 PM

Re: gear or converter
 
Quote:

Originally Posted by Geerhead55 (Post 322095)
After the dyno session, I called ATI and talked to John,, gave him the info he needed, including the dyno numbers and new converter got here last week, can't wait to try it out.
As far as converter cores, the story I heard was that ATI got the cores and the dies to make them from GM after they stopped Opel production years ago, so I don't know about any "copying" going on. I'm sure someone on here is closer to the story and can elaborate on it. Good luck with your project.
Danny Durham

The opel core was the best, ATI had the foresight to reproduce the opel core. ATI, pretty serious about getting the job done! Well, Chance, not so much. When you see a 8 inch converter not built with a opel core, I wouldnt run it.


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