Had a long conversation with Coan yesterday. Faxed them dynographs, detailed specs, etc. For maximum strip performance they recommended a converter that would stall at ~4,600rpm with my combo. I don't doubt this would minimize my ET, but can I live with on the street?

Craig (from Coan) seemed to think so, but he sounds pretty hard core. My car makes decent torque down low: with last years setup it was over 500ft lbs at the wheels as 3,500rpmm and it will be more next year, so I don't think I would lose much with a converter stalling in that range (~3,500), and I am assuming it will be a lot more enjoyable on the street. Any comments will be welcome, I haven't driven a hi-po automatic for many] years, and given the changes in technology I doubt my experiences back in the dark ages mean much.

Please help!

Rich Krause

 

My 3600 TCI is fine on the street. You need a manual lockup and a decent cooler. As far as 4500+/- I have some doubts... Thats a lot of stall for a street car. Personally I would go for it but I would be classified as "hard core" withe the rollbar, decals, and stroker. My car is not pretty.

If you have a decently clean machine and it is primarily a street car I would keep the stall speed less than 4000. If you are primarily a bracket racer and don't mind attracting attention from every officer in the county bump it up and turn some heads.

 

i think its too much...just for the fact you are what, limiting your powerband to like 2000rpm? (4500-6500)

Coan tends to err on the high side when it comes with stalls. I know of a couple other people who ended up with bigger stalls than needed and needed to send them back.

Also that stall wont be friendly on the street with no lockup in a TH400.

 

I have a 5000rpm stall and drive my car on the street. My converter is totally streetable. If the company knows what they are doing a 5000rpm stall will not feel too much different from a stall stock at part throttle but when you nail it, you can definately tell a difference . I have no regrets about going with a 5000rpm stall, although, I was leary at first when the shop recommended that high of a stall for my combo. My converter is a 9" non lockup and will footbrake to 4200 rpm's and flash to ~5000rpm on the motor. The converter was built to handle another 250 hp at the wheels for when I add the bottle. I got my converter from http://www.dynamicconverters.com/.
Later
Matt

 

I think it's too high. I have drven a few with stalls over 4k and just don't like it.

I have a 3200 and with the weight of my car and the power it's making right now it's flashing to about 3350.

The other car we run has a cheapo 2400 SLP that on spray flashes to about 3200. Even when we switch to a TH350, we'll run a stall of no more than 3500 because I want to take advantage of the torque that the nitrous will provide.

If it was an N/A-only combo....then a 4,500 wouldn't seem so radical, unless you wanted to drive it daily.

 

At this point, partially based on these responses, I am planning on 3,500. Keep your comments coming, they are welcome!

Rich Krause

 

depends on the individual converter. my Art Carr 9" non lockup converter in my th400 drives GREAT on the street/highway. it stalls to 4300rpm, but on the street at part throttle is MUCH tighter than my buddy's Vigilante 3200. with a converter that acts like my AC unit, i would feel confident you could easily run that stall on the street no problem

 

My 3200 now stalls at 3500 and I have no issues with it being my daily driver. But a 4600 stall IMO would most likely be too high of a stall for any lengthy street use.

Rich, is it going to be a lockup or non-lockup converter? If it's a non-lockup, I wouldn't envy you driving on the freeway

But then again, you may want to listen to chevyguy3 who has a TH400 and a high stall non-lockup converter.

Sounds to me like Coan is giving you an ideal converter for exactly what you said, "maximum strip performance". While it may be perfect for blasting down the 1320, I honestly don't see it being all too comfortable on the street.

 

Non lockup, but the thing is (and what finally decided me into thinking that I can drive a car with a 1:1 top gear and a non lockup converter on the street) was that that's exactly whay I drove for the ten years after I learned to drive. Most V-8 cars then either had a 4-speed stick or a three speed auto. A 3.42 rear, such as I have now, was considered pretty mild. Most of my cars had 3.73's. In fact, I had a car with a TH400, non lockup converter (they didn't exist then AFAIK) and 3.73's. It was a Pontiac Catalina with a 4-bbl 421. I can't remember the year, might have been a '66? Sweet car, no problem driving it everywhere. And according to Coan, Chance, and others (including what you guys are leading me to believe) converters have improved since then.

So, I am going to try the TH400, non lockup, no OD. If I can't stand it, it's on to the next thing (whatever that may be). Maybe it's be as simple as adding the GV overdrive. But at >$2,000 I am not inclined to try it unless it's really needed.

Please keep your coments coming, and thanks!

Rich Krause

 

I say go for it! It'll be fun going up hills, the beast will scream! Mines pretty loud going up hills with my puny 2600!

 

i would get the stall that they recommended for you, and talk to guys with different converters and have it made by a company that is known for having converters they stay pretty tight at part throttle. worst case, it wouldnt be that big of a deal to pull it back out and have the stall lowered later if you dont like it on the street

 

I still think they are steering you on the high side with your combination. You make a bunch of torque below 4,600rpm and odd are....as I would guess...this thing might stll even higher depending on all the factors that influence stall. I think you are giving up some of your powerband and potential with a stall that high. If you had a peaky powerband like a huge-cammed N/A setup, then a monster stall is all but required to get the most out of it as it will be a dog down in low and mid range.

At part throttle it might be liveable, but I'm not sure I'd like it. The 3200 I have now hits hard when you nail it from part throttle cruise or a standing start. At part throttle cruise it's actually tighter than the 2400 SLP I used to have. Up hills, less than clutch lockup speed, the converter only spins about 1,800 rpm at moderate throttle where the SLP spun to 2,000-2,100rpm. My new one is WAAYYY more efficient.

A guy with a nova that comes to our f-body events runs a high-winding small block, N/A that is very streetable and has a 5,000 (might be 5,500) Midwest stall. He said it drives almost normal on the street (liveable) and is highly efficent. He made a little over 400rwhp on the dyno and ran 10.80s like clock work using a TH350. Craig Watts is his name and he's a real nice guy. Sweet, almost stock-looking early 70s Nova.

Something to think about.