Convertor help
 

I have a 1986 Camaro Ed Quay built , I race it in bracket form now , Has Nesbitt 531 ,power glide 180 straight cut , 4.56 rear weighs 3200 , When I bought the car it would go 5.91 1.27-60ft and put it on the bumper , Convertor broke PTC , Car was shifting 6500 and would go 116.mph . I have been through 3 different companys and all convertors stall 6200 -6400, 1.37 60ft 6.10et 114 mph .Peak torgue @5900hp and 7400 max hp . There are a ton of these cars running SS . I,m at a loss need help please . My thinking is it needs 5500 stall . I sent the new PTC back to lower stall 500rpm ,going to test this friday and see Thanks

Re: Convertor help
 

What did the old converter stall when the converter was healthy? Ray

Re: Convertor help
 

I don,t know , I only know shift is 6500 and so had to be somewhere around 5500. I called PTC and gave them the number stamped on convertor to duplicate but what they sent was to loose ,as soon as i left the starting line it was in high gear

Re: Convertor help
 

It is very possible that PTC did not make the last change to the old converter. If so the stamped number is meaningless. I would try to learn what you can from the broken converter. If you don't know who changed it last send it back to PTC, cut it apart, and see if they can determine how it was built. I would agree from what you are saying that you need a tighter converter.

Re: Convertor help
 

With the MPH down I would say the converters are too loose (% of Slip not stall) compared to the broken PTC.
I like the idea of sending the broken converter to Lane and Kenny at PTC to cut open and study. There is a lot more to getting a converter to work correctly than just getting stall correct. ( Fin size and shape and angle, stator degree and back angle, ect) Like said earlier Your broken converter may have some changes that the numbers don't reflect.

Re: Convertor help
 

You cant have a converter that stalls 6300 and shift at 6500. you said your engine made max power at 7500. That is where your shift rpm should be and that would match up pretty well with the 6300 stall speed. When you ordered the new converters did you tell them the engine max power was 7500?

Re: Convertor help
 

So...
I know nothing...
But stall should be around peak torque and shift at or above peak H.P.
I would send a dyno sheet to whomever you have build your converter...
They should be able to get you real close...
I always had good luck with Coan, and ATI...
Like I said I know nothing, just my going by my experience...

Re: Convertor help
 

Thanks for the replies , The original PTC that blew up was sent to FTI and they said it was not salvageable, My fault for not getting it back , and yes I,m sure it was changed from original specs, I sent FTI, ABRUZZI AND PTC dyno sheet and motor build sheets all convertors where 6200-6400 on racepack also all ran the exact et and mph Great for bracket racing but 10th slow in 60 ft does not wheelie anymore so no rotation . I shifted at 7200 with those convertors , My thoughts are this car was very popular for SS racing and seen alot of them leave harder then what i have . peak torgue is 704@5900 and 804hp @7400

Re: Convertor help
 

6500 is too low to shift.
converter guys all built them for an engine turning 7500+ by looking at the dyno sheet. your 6500 shift makes the RPM fall way below peak TQ. The converter is hanging and can't climb RPM back over peak Tq. If your going to continue to shift at 6500 you need a converter built for the power curve from peak TQ to 6500 on the dyno sheet. Your leaving power and ET on the table.
Shift it at 200 above peak HP on the dyno sheet with the converter you have and look at the ET/MPH.
You need to have a serious conversation with a good converter guy.. not a salesman.

Re: Convertor help
 

This may not apply but just thought I would share. I raced a stock eliminator Chevelle for years and it suddenly lost all it had, 60ft's, consistent lights,winning rounds were gone. I tried tires,converters, gears, rear suspension,shocks, nothing worked. I was telling a very talented racer my problem and they said, How old are your front springs ? They were Morosos at least 20 years old, I replaced them and everything went back to the way it used to be. If I was chasing something it's the first place I'd go.

Re: Convertor help
 

That last post brought up a memory of a customer problem.
He had a major converter trashing.
Put the same part# and brand converter back in it and it was slow.
Like the OP is experiencing.
Finally found the Stator support tube that presses in the front pump had slipped and restricted a hole or two.
An aftermarket stator support aligned properly brought back his good numbers.
Just food for thought...

Re: Convertor help
 

Good thoughts guys but shocks in front are lakewood 90/10 and are fine , also the trans has been changed also I have 2 each time and same results , I bought a new front pump from Abruzzi and input shaft still the same, I went to Bradenton last friday with the PTC tighten 500 rpm according to race pak and same results 1.38v 60ft 6.10 et and no rotation on front , I am pulling motor and sending back to Nesbitt for check and freshen up . This is the only thing I have not done yet . I have changed the distributer,coil,msd box you name it its been changed lol. I,m tired Thanks For your help .will keep posted when the motor comes back .