V-10 Killer

iTrader: (22)

I checked some logs from at the track and romping around town and noticed that there was a lot of difference between my engine rpms and input shaft rpms at full throttle. The best I came across for efficiency was 92%. My TC is only a few weeks old and I'm considering sending it back and having it reworked/replaced. Here's a few snapshots from my logs:







What kind of slippage is everyone else running with 3600+ converters?

Thanks for your input.

JNorris

iTrader: (4)

92% seems about right for 3rd gear at WOT with 3.23 gears. It is low for 1st gear with 3.73 gears.
What is your setup?

V-10 Killer

iTrader: (22)

FLP Level 5 4L65E tranny. TCI3800 stall lock-up converter. Strange 12 bolt w/3.73 gears.

12secSS

iTrader: (30)

WOW! By the looks of that, you are at best 90% efficient, worst being 88%. And by the MPH and your 3.73 gears you are in second! That is terrible, even for a 3800 stall. Do you know what the STR is? Does it hit hard coming out of the hole? What size is the converter?

BubaGumpShrimp

iTrader: (1)

the efficency has to do with the str, higher the str the lower the efficency but the better the launch. Tci's converters are usually 2.7 str.

jimmyblue

iTrader: (11)

Hard to make out what efficiency ratings are and it
seems some mfrs play games with theirs (like rating
at 7000RPM or higher, even).

I've tried to collect data here before but not much
has surfaced. My TCI 3000/2.2 showed 94% at 5000
climbing to 97% at 6000 on a 2nd gear pull (below
5000 it is apparently still multiplying because my
efficiency calcs were > 100%). I have some dyno
data for a TCI 3500/2.5 car but it is very "bouncy"
as if there was some roller or driveline resonance.
Not a stable, climbing profile as you would expect
to see.

If you can export an Excel snippet of the run I would
like to add it to my new collection (in-vehicle, road
data for converters to compare efficiency).

V-10 Killer

iTrader: (22)

The 3800 TCI is a 2.6 STR 10 inch lockup torque converter. The 4000 is 2.7. I haven't recieved my Bogarts so I can't see just how hard it hits coming out of the hole, but it's certainly more than street tires can handle.

Jimmyblue, I can export it and e-mail it to you, but I don't know yet if this is typical or atypical for this type of converter. So I'm not sure you should use it as a "baseline".

12secSS

iTrader: (30)

Ah, I did not know TCI used such high STRs ... the 2.6 would explain it the lower efficiency. If it was larger than a 10", then I would say it would be the size. Larger converters restalled to those high stalls (3500+) start to lose efficiency fast.

V-10 Killer

iTrader: (22)

Jimmyblue, I e-mailed an xls file to your hotmail account. Thanks for looking at it.

So in review, should I accept this as how the converter is, or should I pull it and send it back?

BubaGumpShrimp

iTrader: (1)

all depends on the track times and if your satisfied with it. The loss in efficency up top is probably made up for an improved launch out of the hole. Its a trade off of how hard of a launch you want vs efficency. You could send it back and say you want it to be 95% or better efficency but i will bet any money that the launch wont be as hard. The more you increase str the less efficent as well as the oposite the more efficient the lower the str. You probably know that already? I have been looking at getting a new converter and asked many of the sponsors lots and lots of questions, as i dont want to have to change converters again(went too small to start with,look at sign) I think the best info i got was to go with an str just low enough of roasting the tires(ex 1.6-1.9 str for street tires,2.0-2.5 for drag radials, and anything above 2.5 for full drag slicks) after you pick that than you can work on what stall(should be based on what cam you have and where the peak tq is made)
Well according to your sign you got some good times and with the converter you just got you should be able to drop that 60'time a bit more and net you a better et

V-10 Killer

iTrader: (22)

I guess the loss in efficiency wouldn't bother me so much if it were typical for a ~4000 stall converter. TCI told me they usually rate these efficiencies based on relatively stock to mildly built motors. If some numbers someone crunched for me are correct, I'm pushing ~505 fwhp, which could explain blowing thru the converter a little more than what TCI would rate for.
Unfortunately, the times in my sig are from last year on spray and street tires, but less stall converter. My only time out with this converter yet this year netted me a 12.249 @ 119mph with a 1.887 60' on my 18" rim street tires, motor only. I only got a few runs in before we had to leave to get a trailer for my friends car... I'm hoping to get down to at least a 12 flat on street tires N/A (hopefully 11.9xx), and this converter plays a big role in that. But anyway, I picked up a set of MT ET drags, and am currently waiting (and waiting, and waiting...) for a set of Bogarts to put them on.
I guess I'll just have to use different bragging rights. I was hoping to put it on a dyno and hit around 420 rwhp on motor, but with this much slip, I guess I'll have to deal with ~400 rwhp instead.
A big issue for me now is not having my TCC. I'm still trying to figure out if that's the converter or the new FLP tranny. Even using my HP Tuners cable, it won't lock up at all.

BubaGumpShrimp

iTrader: (1)

with a good tire i could see you easily pulling a 1.7 60' probably 1.6's and that means 11.99et or better. Would say in your case the tire is totally holding you back as for the true potential of the converter. So hopefully soon you will have your et drags and a much better time slip. I would say dont worry so much about the efficency cause you will sure make up for it in the launch and the 60'times. Someone with a converter with the same stall and higher efficency wouldnt launch as quick as you would, but would probably start catching up to you after the 1/8 and be equal to you at the finish line. The converter probably would be 2.0str,3,800 stall would equal what you have now, you get the lead first,than he starts catching up and you both cross the line at the same time. Maybe now you can see what i mean by give and take in that comparison of converters. The only way to increase your efficency and keep the stall the same would be to decrease the str, hence you will have less of a take off out of the hole... As for your dyno numbers dont look at thoes too hard either as they really dont mean much other than bragging rights to your friends. Time slip means everything cause a guy could have a 450rwhp car and not beat you cause its not set up right. Just look at my sign, my 60' sucks donkey ***** and someone with less power but better traction can bet me even though i can go around and say my car has 310hp the wheels, so what the guy with 280 just beat me... Just trying to show you numbers,weather it be dyno or efficency dont mean jack, its all in how it comes together as a package. Now dyno numbers are a USEFULL TOOL in letting you know if what your doing to your car is good for it or not....

jimmyblue

iTrader: (11)

Here is the efficiency graphed the same way
as I did the TCI3000. Quite different efficiency
at the lower RPM, very much more peaky.