Road tested new Dirtydog 3500 stall converter

David Neibert

SCCoA Admin
I got the converter installed about a week and a half ago in my 91 SC, but didn't get on the go pedal very hard because of a vibration that turned out to be the exhaust hitting something.

Now that the vibration is fixed and the weather is nice I drove the car to work today. While trying to accelerate around a car that was blocking me from getting into the left lane so I could merge onto the highway, I must have gotten on the gas pedal a little too hard because, the tires started spinning and I was instantly sideways at 40 mph :eek:

I think it scared the people in the car I was trying to get around more than it did me, because my rear bumper was only about 3 ft from the passenger's door and it looked like she was screaming. I managed to get it straightened out without losing any speed and went on around them and merged onto the highway. They stayed back several hundred feet after that.

I haven't tried it yet, but I'm pretty sure this thing will now easily spin the tires from a 55 mph roll. It's a lot more slippy feeling at cruising speeds and takes about 2900-3200 rpms to go 70 mph depending on the grade. Alan suggest switching from the Merc Dex III to John Deere hydraulic fluid to tighten it up a little at cruising speeds.

I've also noticed that the transmission is running about 10 degrees hotter than with the Lentech 2700-2800 stall, but at 165 it's still well within the safe zone for operating temps. The JD fluid should lower the temps about 10 degrees, which will give me some extra cooling capacity in summer traffic.

With the footbrake I can hold it to about 3000 rpms before the tires start spinning, so I'm sure it will flash at about 3500, which is right in the meat of the motor's torque curve. I'd like it a couple hundred rpms tighter at cruise, but all things considered...I'm happy with the switch.

David
 
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Seems to be very similar to my converter. However, it has been so long since I've driven my car, I cannot say for sure.
 
Seems to be very similar to my converter. However, it has been so long since I've driven my car, I cannot say for sure.

Kurt,

Yeah it should be a lot like yours, since that's what I asked Alan to build. Tired of you and a couple others killing me off the starting line. Between the converter and new tires I'm expecting to improve my 60ft times to low/mid 1.5s instead of mid/high 1.6s.

David
 
Kurt,

Yeah it should be a lot like yours, since that's what I asked Alan to build. Tired of you and a couple others killing me off the starting line. Between the converter and new tires I'm expecting to improve my 60ft times to low/mid 1.5s instead of mid/high 1.6s.

David

Could be the ticket to a 10 sec. time slip..........;)

If/when I get a high stall converter I should be in the 1.4's 60 fts. I'm already pulling 1.5's.
 
What stall do you have now ?

David

It's suppose to be a 2800 stall but I can't get it above 1000-1200 rpms without pushing me through the beams so I've been launching at about idle with resulting 1.5 60 fts. I think the cam that I have is the culprit for having low vacuum in the lower rpm range. In gear and at idle, 950 rpms, I only have 6 in. I've checked for leaks and can't find any so maybe I need to put on one of those vacuum cannister/reservoirs, I don't know.
 
It's suppose to be a 2800 stall but I can't get it above 1000-1200 rpms without pushing me through the beams so I've been launching at about idle with resulting 1.5 60 fts. I think the cam that I have is the culprit for having low vacuum in the lower rpm range. In gear and at idle, 950 rpms, I only have 6 in. I've checked for leaks and can't find any so maybe I need to put on one of those vacuum cannister/reservoirs, I don't know.

Keith,

Since you have the ability to lock up the converter on demand, there is no reason why you can't go a lot higher on the stall. I would think 3500 would be your starting point.

Yeah my 93 has the same late model brake system and it's very sensitive to low vacuum. I was able to improve mine by adding some check valves in the vacuum lines that are normally hooked up on the inlet plenum (that were not intended to see boost) and putting a new check valve on the brake booster. I've also got a vacuum canister that needs to be installed inside the fender.

Mine is only a problem when quickly going from boost to hitting the brakes, such as when doing a burnout at the track and trying to stop before the tree.

Really looking forward to seeing what your car does this year.

David
 
Sounds good, David. I knew all you, and very many others, needed was a slippier converter!!
 
Sounds good, David. I knew all you, and very many others, needed was a slippier converter!!

Thanks...I don't really care for the extra slip on the street, mainly because it puts the engine rpms into the area where the exhaust sound is extra annoying. But if it pulls a significantly better 60ft time, I'm sure I'll get used to it.

David
 
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Isnt that big stall exciting tho, 3500 and BAM its on. Cant believe you're still a die hard AOD guy. Nothing like dropping the clutch on a car making 600 hp while its throwing a fit at 4k shooting fire balls.:cool: I think that converter might edge you into the 10's. Should be much more exciting coming out of the hole. Pair that with the QH to see exactly where you're shifting and youll be knocking out some quick passes this year.
 
Isnt that big stall exciting tho, 3500 and BAM its on. Cant believe you're still a die hard AOD guy. Nothing like dropping the clutch on a car making 600 hp while its throwing a fit at 4k shooting fire balls.:cool: I think that converter might edge you into the 10's. Should be much more exciting coming out of the hole. Pair that with the QH to see exactly where you're shifting and youll be knocking out some quick passes this year.

It might be more exciting on the track, but I already had more power than I could put down on the street with the old converter, so it's not really a plus for street driving.

I've owned several cars with manual transmissions and always thought they were superior to automatics, but for an SC I think the automatic is a better choice. I'd add a shift light, but it would probably just confuse me.

I'm also counting on the 95mm TB and bigger air intake system to add a little more power. I was perfectly content with going 11.5s, but now that Chris Vinning had shown everyone what is possible, I'm pretty motivated to get well into the 10s without using the bottle.

David
 
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I'm also counting on the 95mm TB and bigger air intake system to add a little more power. I was perfectly content with going 11.5s, but now that Chris Vinning had shown everyone what is possible, I'm pretty motivated to get well into the 10s without using the bottle.

David

Feels like everyones expectations have climbed for 1/4 mile times and rwhp. I really wished the SCCoA would do an accurate 1/4 mile times and HP lists. Pretty much every car club out there has those two lists displayed proudly:confused:

Ken
 
Yep like that. I hope to dyno the car later this month and see if I have eliminated the recurring electrical glitches that have plagued me in years past. Maybe I will have some new numbers and post on the TBU

Ken

Ken,

You can post what you have now, and have the numbers updated later. It usually only takes a day or two from the time you submit the info.

David
 
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