You know, always looking for interesting input....

'72 Supreme, 403 10:1 w/ Lunati 60803 cam (227/233 @ 0.050), Performer RPM intake and qjet, TH350 and 3.73:1 rear. Daily driver.
Currently have a TCI Saturday Night Special in there. About 1800 stall stopped, ~2200 when rolling. It's hard to get a good idle, so wondering if it needs a little higher stall.

Thoughts?
Don't want to spend more than $500, seems the Coan entry level unit might be a good idea.

 

I ran a tight converter on a big cam it took some tuning but it didn't pull in drive. I ran that same converter at one point. I think your converter is fine but a little carb tuning can make a difference. what I did with mine was I leaned up the idle, turned down the fast idle and put the vac. adv. on an unported vac. source so the engine would idle good. I also assume you are having issues with it idling well in drive. Right now im running a 512/512 227/234 duration cam on a 10 to 1 355 I currently have a 2800 stall but going to something a little bit tighter .

 

Lunati recommends a 2200-2400 converter.

http://www.lunatipower.com/Product.aspx?id=1723

 

There is a member here selling a tci breakaway converter which will flash in the 2400 rpm range .

 

Gracias.
I've been through the qjet many, many times. I have everything except idle spot-on. It gets really rich at idle (12.5:1), and any leaner just dies. So right now it's ~750 stopped in gear, ~1100 idling. Vacuum in gear is 15".
Ignition is a MSD 6AL2, with a boat load of initial timing. It has Edelbrock heads and just loves early spark everywhere except lugging. Got a perfect curve right now (pending dyno pulls).

 

What distributer? Whats your timing set to, initial and total mechanical?

 

An 11" converter with no more than 2200 is all you would need. I think I would just leave the existing one in there.
That cam will act a little more mellow in a 403,compared to a 350.The difference in cubes will do that.1800-2200 is good.

 

I recomend a tight 10" converter from Ultimate Converter Concepts. I had an 11" TCI in my car prior to the 10" UCC. There is nothingthat I don't like better about the one I have now. It cruises at a lower RPM than the TCI yet flashes higher and hits hard when you whack it. Lenny knows his stuff and will be building the converter for my new race car.

 

Chadman can you pm me roughly what he charges ? Been shopping around for a new custom converter. The one I'm trying in the test run for the th350 I rebuilt is just a jegs shelf unit I plan on replacing once I know it works well

 

FWIW, the Coan guys recommended the "Pro Street" 11" w/ 2400-2600 stall. I asked about the "Street Performance" and the response was:

 

Chad,
I agree,the best way is to have a converter built for the car,but I wasn't sure that he wanted to go that route,and the one he has is not THAT bad for what he's doing.
I tested A LOT of converters in the 72,before I got what I wanted.I ended up having Chris at Continental Converters build me a "tight 10". It is the best of both worlds.I can cruise around town and get nice drivability,and I can take it to the track & murder it,and it does what it should.I've had the best ET's with this one.

 

I use to work at Coan years ago, they do make a excellent converter. I had that same converter in my car years ago, it worked well in my car. I dont think you will be disappointed. A good converter is money well spent.

 

Most of the off the shelf generic converters are ineffcient junk. Listen to Chad on this. There are many good converter companies out there but until you get to thier race converters TCI is not the way to go. (I still wouldn't use TCI in a race appication but ther can make a decent converter)

 

Yeah, custom is always the "right" way, but the $425 price tag on the Coan already has me paused......

 

My Continental was $550.00 to my door.
I tried a custom-built TCI,and I split the inside.
Your typical production/shelf converter has a vague application,and usually designed around something popular,like a smallbblock Chevy.It may or may not perform as advertised.

 

I called midwest converters in rockford il. and they said 380 for a 10 in. Built to my specs