This morning was the 1st time I had a chance to check the converter stall on our 68 Camaro. I ran this car for the 2019 season. Anyway, I always thought the converter was tighter than I liked. It ended up at 5,400 on the brake. Not where I would like it, but it's the secondary race car.

I really wanted to discuss the converters in our 80 Camaro. The engine made peak HP @ 6,000/6,100 & peak TQ @ 4,600. I have 2 converters that I use for this car. One 8" & one 9" they both stall within 50 rpm of each other @ 5,9xx rpm on transbrake. Both are great good working converters, that win races. I can't figure out why they work so well being well above the TQ peak & just below the HP peak. I have no data logger & can't remember the fall back rpm. It has a 1.76 glide.

I do have another unknown 8" converter, that's tighter. It was in the 68 Camaro & it stalled around 5,000 if I remember right. Not that I need to pick-up ET, but is that what you think would happen with a tighter converter.

This message has been edited. Last edited by: B KING,

One of the best investments you can make to your racing program is some sort of data logger.

Even a simple Racepak Sportsman will give you alot of useful info with the basics being engine rpm and driveshaft rpm.

It's often said that loose is consistent. Only way to know for sure what your car likes is to experiment.

Dealing with a converter company and giving them accurate info will put you really close on a new converter.

quote:

Originally posted by DOTracer:
One of the best investments you can make to your racing program is some sort of data logger.

Even a simple Racepak Sportsman will give you alot of useful info with the basics being engine rpm and driveshaft rpm.

I agree with that on the Data logger.

As for the Convertor I would call Hughes converters and talk to them. I always say if you are not sure on the stall go with one on the high side (With in reason) If stall is too tight car is a dog and may not be consistent. If it is a little on the loose side will still work good.

If you’re looking for a less expensive (than Racepak) way to log engine rpm consider adding MSD Grid 7730 to your present analog ignition. Grid will log the 19 channels that it controls.

Grid 7730 offers much in engine control if desired.

I here you guys on the data logger & somewhat agree. I've always raced doing more with less & not necessarily the other way around. I've never been one to try & keep up with the Jones-es per say. I'll not say never to the data logger, but it's not in the future plans.

I have 4 converters: ATI, TCI, Hughes & an unknown. All of them 8" except the Hughes (9").

None of them stall where I think they should. I don't worry about it too much. I win my fair share of races, championships, Wally's, bigger races/paydays, but no super payout/big race yet.

The 2 converters being used in the 80 Camaro. Just seem to be way outside the normal for a converter to work.

quote:

Originally posted by markemark:
If you’re looking for a less expensive (than Racepak) way to log engine rpm consider adding MSD Grid 7730 to your present analog ignition. Grid will log the 19 channels that it controls.

Grid 7730 offers much in engine control if desired.

I have a programmable 6al-2 in both cars, if or when I will decide to log. I would probably go with the grid to log & use its other features.

quote:

Originally posted by B KING:

I really wanted to discuss the converters in our 80 Camaro. The engine made peak HP @ 6,000/6,100 & peak TQ @ 4,600. I have 2 converters that I use for this car. One 8" & one 9" they both stall within 50 rpm of each other @ 5,9xx rpm on transbrake. Both are great good working converters, that win races. I can't figure out why they work so well being well above the TQ peak & just below the HP peak.

Torque = HP x 5252 / rpm

So hypothetically if the engine makes 640hp as example at 6000rpm, the torque is 560 pd ft at 6000 rpms

So hypothetically if the engine makes 510 hp at 4600rpm the torque is 582 pd ft at 4600 rpms.

So the torque converter below stall multiply's the torque between the given hypothetical values keeping the engine rpm accelerating.

If the stall is 4800, less torque is multiplied and the engine doesn't accelerate to peak power.

Now if you had a 3 speed transmission with a high starting line ratio you could perform well with a lot less stall substituting mechanical torque multiplication for below stall torque multiplication and the engine would accelerate through the power range.

For Super Pro bracket racing all the data you'll need is in a Mega 400 delay box. Race RPM Replay.

You guys keep talking about putting loggers in, and similar to fishing I seen a lot of guys wandering around trying to figure out the electronics and not fishing (or racing). For those who aren't "computer people" (like me), its a long learning curve. Some say you better get used to it, I'm trying but a 19 yr old girl at work knows more about a computer or anything to do with one than I ever will, and it's frankly embarassing.

In my opinion the 80 would be quicker with a 5,000-5,200 stall, but I'm not concerned about going faster. Here's one of the 80 Camaro dyno sheets.

I've done lots of converter testing in my dragster. I've found that a data logger is necessary to really understand what the converter is doing. Two converters that flash the same on the brake with the two step chip out can paint very different graphs. Some of them keep the engine revving up and others hang at one RPM(or even drop back) for an extended period. In my opinion, if you're serious about learning about converters and dialing your combo in, a data logger is necessary. That's not to say that you won't be able to get a converter that will work if you don't have a logger, but after the testing I've done I now know what I want the graph to look like for my combination.

These runs are all with the same car and engine. Ron's injected 555" in a 1920# dragster with a 4.10 gear that goes 7.40s, 30s in good air.

Click the thumbnail for a larger picture:

quote:

Originally posted by B KING:
In my opinion the 80 would be quicker with a 5,000-5,200 stall, but I'm not concerned about going faster. Here's one of the 80 Camaro dyno sheets.

My hypothetical was pretty close LoL! No sir 5000 - 5200 would be a tenth slower and inconsistent.

quote:

Originally posted by 183N:
I've done lots of converter testing in my dragster. I've found that a data logger is necessary to really understand what the converter is doing. Two converters that flash the same on the brake with the two step chip out can paint very different graphs. Some of them keep the engine revving up and others hang at one RPM(or even drop back) for an extended period. In my opinion, if you're serious about learning about converters and dialing your combo in, a data logger is necessary. That's not to say that you won't be able to get a converter that will work if you don't have a logger, but after the testing I've done I now know what I want the graph to look like for my combination.

These runs are all with the same car and engine. Ron's injected 555" in a 1920# dragster with a 4.10 gear that goes 7.40s, 30s in good air.

Click the thumbnail for a larger picture:

I agree but if you have a Mega 400. The race RPM replay is the graph you speak of.

Yeah I have a Mega 450 and used the RPM recorder on that before I bought the data logger. But it's much easier to see a visual graph than watching how the numbers change while pushing the up and down arrows.

quote:

Originally posted by 183N:
Yeah I have a Mega 450 and used the RPM recorder on that before I bought the data logger. But it's much easier to see a visual graph than watching how the numbers change while pushing the up and down arrows.

I agree, but the engine acceleration early in the run is the focus. Holding the up button tells you immediately if it's a workable scenario. When the mega 400 came out, I knew that mode gave anyone using one (400), a leg up. These came out before racepak became the norm.

I got no problem with data and I agree with you, but if you're limited in resources like me, on a shoe string budget, race rpm replay is all you need. A guy can get real good with it.

i used to print my 450 with a dot matrix printer and the handheld device

quote:

Originally posted by rusty:
i used to print my 450 with a dot matrix printer and the handheld device

quote:

Originally posted by 183N:
In my opinion, if you're serious about learning about converters and dialing your combo in, a data logger is necessary. That's not to say that you won't be able to get a converter that will work if you don't have a logger, but after the testing I've done I now know what I want the graph to look like for my combination.

Thanks guys for the discussion!

I should have been clearer on the OP. I wanted to have discussion on anybody's set-up or opinion. I only used my one combo as a starter. Because I thought it was on the high side of the norm for stall on a low rpm engine.

quote:

Originally posted by Mike Rietow:

quote:

Originally posted by B KING:
In my opinion the 80 would be quicker with a 5,000-5,200 stall, but I'm not concerned about going faster. Here's one of the 80 Camaro dyno sheets.

My hypothetical was pretty close LoL! No sir 5000 - 5200 would be a tenth slower and inconsistent.

Yes, it was!

The 2 converters for the 80 are 2 different animals in the car. I prefer the 9" in the 1/8 mile & the 8" in the 1/4 mile. They both win races & most of my racing is 1/4 mile.

quote:

Originally posted by mavman:
You guys keep talking about putting loggers in, and similar to fishing I seen a lot of guys wandering around trying to figure out the electronics and not fishing (or racing). For those who aren't "computer people" (like me), its a long learning curve. Some say you better get used to it, I'm trying but a 19 yr old girl at work knows more about a computer or anything to do with one than I ever will, and it's frankly embarassing.

Start dating a 19 year old girl. Solves several needs.