Torque Converter Install and Question

[Red5Ltr]

First look below at my signature to see what I have in my Mustang.

I had a 3000rpm stall converter put into my Mustang the other day. This converter is a non-lockup converter. I also have a Transgo shift kit in my AOD tranny. Well, the car used to be pretty jumpy around 30-35mph I could stomp on it and it would throw you back in the seat and now it pretty weak. I also had to have the tranny filter and fluid replaced because the fluid in the converter was pretty dirty. I guess I don't know enough about how the whole torque converter thing works exactcally. I guess with a higher rpm stall I was expecting alot more than what I have. When ther tranny was dropped to get the converter in is there something that needs to be adjusted?

I need your help with this.

Thank you all

John

[crazypete]

First of all, something must have been done wrong. I swapped out my stock TC for a 3000 stall TCI street fighter and it turned the car into a beast! I am also running the transgo kit on my AOD and I switched to 4.56's from my 3.73's.

The only thing I can think of is that your torque curve starts lower than the converter stall and that will negatively affect performance. Otherwise you should be whipped into the seats as much as before.

My transgo kit seems to favor higher gears and is less prone to downshift. This might be your problem, running in a higher gear. How are the shift points and gear selection? Maybe a tightening of the TV cable is in order to leave you in a lower gear.

[Red5Ltr]

I have 3.73 gears in my Mustang and I guess I'm not sure as to what the issue is. Is your StreetFighter a lock up or a non-lockup. I was told that I should use a non-lockup with my setup. I was really expecting a huge difference. It seemed so much better with the old converter in it with the exception of the off the line start. I can really break the tires free easy and the shift points seem a little high now. Before the install I could really feel the shifting and it was hard, now not much. Do you think it needs something adjusted.

Thanks all.

[crazypete]

Actually, I'm running a lockup, which is why I went with such steep gearing. I have acceleration in OD!

Nonlockup should give you torque multiplication through all your gears unless you're driving around above 3000 rpms and then the converter would be stalled and you wouldnt see any difference.

I dont think there is anything to adjust other than shift points. Maybe tighten the TV cable and achieve better shifting and see if operatring in lower gear or staying in lower gear longer produces the umph you are looking for.

If the verdict is that the 3k stall is worse than the stock converter, then I believe that you might have gotten a bum converter. I got ripped off once by buying a 2k stall on ebay which was nothing but a stocker painted purple. Was your TC from a reliable source?

[Red5Ltr]

I bought the TC from a guy on eBay that builds them. I read the replys that he had and they were all positive replys and the guys hasn't had a negative reply. He recommended a non-lockup because of the shift kit and the gearing. I'll try starting in low 1 and working my way though the shifts. I could start in 1st gear (Low 1) and shift to second (low 2) and squack the tires. And even leaving it in drive it would shift hard from first to second. Now it wants to run in the higher rpm range and I can't really feel the shift like before.

[Rev]

It sounds like the convertor never really stalls or "couples" as they say. It may be slipping all the time even at and over 3000 rpm. I'm only guessing of course, but that's what it sounds like.

Rev

[crazypete]

I dont know about you guys...but I have yet to run across anyone on ebay that doesnt have phenomenal ratings =) . I think the system is skewed. The guy who sold me the stock TC had phenomenal ratings. Bottom line is TC's are such a quality dependant item that it only makes sense to buy from a reputable company that can guarantee the quality. I was out $200 bucks on my ebay'ed converter. Had I bit the bullet and spent $300 I could have the TCI that is riding under my car right now.

[Red5Ltr]

This is what the guy I bought the converter from replyed to my question that I posted here. What do you think. Can someone tell me what I would need if this is correct?


3000 should not be too much for a healthy engine but it will take the firmness out of the shifts i suggest increasing throttle pressure to 35 lbs and setting the transgo with the hardest shift pattern available for firm shifts also you will notice this converter is not direct drive so you will not feel the bangs in 3rd and 4th gears but you will have more power there what stall rating did you get with your gears the car it was tested in went to 3100 before the tires would spin i would guess you should have gotten about 3000 with your gear ratio
what servo are you using i highly recommend the A overdrive servo
it is possible that the added torque going through the input shaft could be causing your clutches in the trans to shift on apply
also what rpm are your wide open throttle shifts coming in at alot of these trannies had really early shifts and the fix was to use either the high rev governor kit that is included in the transgo aod-hp shift kit or use a supercoupe governor
do you have any extra clutches in your transmission?
from my experience the only means of making firm shifts in these transmissions with a high stall torque converter is by adding extra clutches and a wide band but if you are going to do all that go for the wide gear ratio too and you will love the results.Bold

[crazypete]

I went from the B servo (stock) to the "A+" servo and noticed only a slight increase in "bang" going into 4rth. I would reccomend it but I dont think it will solve your problem. The TV pressure should be 35 psi already. I installed the transgo AOD-HP kit with the most agressive settings and the high rev governor. It shifts nice and firm.

How old is the transmission? The bands _could_ be worn ,as the man said, but... if it was a screamer before, then it should be a screamer now and you cant scream much on worn clutches.

A quick fix would be to keep tightening the tv cable a notch until it shifts as late as you want it to. Dont go too crazy or you will overpressure the system.

Did the guy implicate that he tested it? Was there oil inside the converter? That is the only way to test it is to drive around on it. If it was squeeky clean inside then I doubt it was tested. Maybe there is something I dont know, but I'm pretty sure you need to fill it up to test a converter.

the car it was tested in went to 3100 before the tires would spin i would guess you should have gotten about 3000 with your gear ratio

Gears have nothing to do with stall. It has to do with the torque curve of your engine. You want the stall to be 300 rpms below the max torque. Stock is 3000'ish. If he tested it in a high revving motor, he might have gotten 3100 stall from it while a less powerful engine might only produce a 2800 stall or so. TC selection is a pain in the @ss and somewhat of an art unless one has dyno specs, vehicle weight and gearing info and someone builds them a custom TC. Gearing is important for what the car can do with the torque from the hopefully locked up converter.

I say install the highrev governor if you havent already done so (you can do it with the AOD in the car, just pull the tailshaft housing). Then tighten the TV cable to get your desired rpm range. If still no luck, get upset, put your old TC back in and ebay off your current TC as a "kick@ss 3100 stall converter!" and charge $100 more than what you paid for it. =P

[Red5Ltr]

When I bought the car the work on the tranny was done a year prior to me buying the car. I'm not 100% sure the shift kit is a Transgo, but I know there is a shift kit in it. When it would shift from 1st to second it would shift hard and squawk the tires. Now it revs high and the shifts when I'm in drive are very hard to notice. I believe that is the point of a high rpm TC is to be able to run higher rpm's and stay in the power band. If I'm understanding this correctly. I can bust the tires free without any problems when it was a bit harder before without having to power brake. The converter was installed because I have to have my tranny flushed because the fluid was burned up. I hope the converter isn't burned up. I'm not saying that I don't feel a change, I do, but I was expecting alot more throw back into my seat feeling and it was better with the other converter.

Thank you,

John

[crazypete]

the car it was tested in went to 3100 before the tires would spin i would guess you should have gotten about 3000 with your gear ratio

Wait a second.....3100 rpms before the tires spin?!? Does he mean "begin to turn over"?!? A 3000 stall will start to turn much much much sooner than 3000. I think that is the flash stall speed. The true stall is much lower. If he had to rev it to 3100 before the tires started moving at all, then this is some sick 5800 stall or something converter.

The purpose of a torque converter is to allow the engine to spin up more before engaging the drivetrain. Your rpms are controlled by your shift kit and the tv cable...shift points. A low stall converter will start the car moving at lets say 1200 rpms and a high stall will wait till 2000. This is what the official line is. I, personally, have never seen that advertised behaviour. I'm not sure what the 2000 and 3000 stall number engineeringly implies but it is not the speed at which the car starts moving. My car will move at 600 pms when I take my foot off the brake and it will move at 2000 rpms which is my cruising rpm. This is why I'm like "huh" when the guy said to you it starts spiining tires at 3100.

Actually, since it is no-lockup, maybe you get converter slippage when you gun it now since you are not near the converter's stall speed and this robs you of tirebarking snap that you used to have in 3rd when the direct drive shaft locked up.

[Red5Ltr]

No No My Mustang is moving at idel speed and it just seems the rpms are moving up faster than I am and I'm not moving as fast. Kinda like some said it's almost like it's slipping some. I'm not sure when the tires break loose maybe around 2600 rpm's. I guess that I was moving faster with the old TC is because it was a lockup type stock TC. I can feel like I'm accelerating faster at higher speeds, but I don't get the throw back that I was looking for. Maybe that is just getting the TV cable adjusted so the shift points are harder. What I hear I will lose some of that because the tranny is operating at a higher torque curve. If I'm wrong please someone correct me.

Thanks for everybodys help and advice

[420nitro]

I just wanted to state something....
But please understand this is not a flame or anything like that. All the info so far seams to be accurate (because, I claim not to be a converter or transmission specialist.) but the statement made by Crazypete:
"gearing of the car has nothing to do with the stall speed"
....is completly incorrect.

Besides the torque curve of the engine you must account for:
vehicle weight...
gearing...
any power adder..
cam shaft profile... (how big and how much duration...
cylinder heads..
etc, etc, etc...

A good torque converter company will take all of that info, plus about 20 additional questions into consideration before designing a converter for you or matching you with a proper one. Due to the FACT that any of those things can alter and change your final stall speed! I have spent well over $2,000 on VARIOUS converters and finally bought one from Lenny at TCT converters and now I am completly satisfied! You get what you pay for!
My .02's

[420nitro]

Another common mistake is, asking for a certain size converter or stall speed. WAY to many variables! Leave that to the pro's to tell you what you need! Explain what you have, and the intent purpose of the car. Then you will get what you need. It's almost like asking for a 3/4 race cam.
Don't get me wrong...there are alot of us here that have a very good foundation of approx what size and what stall speed we would need for a combo, but leave it to the pro's and question their response if you don't agree.

[crazypete]

I guess the gearing affects how the TC sees the weight of the car, so you are right!

Though with his combo, he should have seen similar results to mine since the cars should be in a similar class (I had 3.73's with that converter before my gearswap).

So what is the consensus about the "standardized" TC's like the B&M's and tci's. I love my tci and they told me between 2800 and 3200 stall for my application.

I vote that the car in question is having massive converter slippage. Do converters ever have bad/weak.....clutches(?) in them?

[rwhite65]

This is also not intended to offend anyone, but here is my opinion. I have also had a few different T.C's in my stang, and was unhappy with all of them. My first "performance tranny was a B&M....and I could tell no difference with it over a stock.

This is one of those places I really would advise.....save ur money...and get a quality piece. You really will get what you pay for concerning T.C.'s. They will ask u lots of questions about your car....they know what they r doing if u talk to the right places.

It sucked dropping the cash for the T.C. I bought, but I will say it was the best performance decision I made (except for gears).
Ryan

[420nitro]

Originally posted by crazypete
I

I vote that the car in question is having massive converter slippage. Do converters ever have bad/weak.....clutches(?) in them?

The converter has several different things in them that can cause some of the effects that he is discribing. He might have a bad or broken sprag in the converter. Could have broken it due to various reasons or possiably a defect from the get go.
Like rwhite65 has mentioned...same your $$$ and get a good converter. For the power range he is in I believe the Precesion Industries would be fine. Get it NEW! Comes with a 2 year warranty and if you need a stall change for what ever reason, they will change it for free, the first 2 years to the orginal owner. I honestly broke 4 of them! People swear by them, but once yoy start going into the 10's using a trans-brake....they aint worth shit! IMO. Everyone I have delt with claims the same thing. You need to dtep up to a $1,200 converter on up. Like TCT, Neil, ATI,Cone,etc.

[rwhite65]

I am no where near the 10's, but I think it did come with a warranty. I would have to look at the paper work.
Ryan

[420nitro]

Yea some people have great luck with them...even in the 10's but I didn't.
At this point, I would have to say it would be foolish to spend the money for a TCT, Neil, ATI, etc units due to the amount of $$ involved. But a PI converter is what I believe he should be looking at, with the level of his current mods.

[Red5Ltr]

What is a PI converter or what is the mfg. name? I guess I would have needed someone to drive the car before installation and after to see what I'm talking about. It will roll the tires with no problem when I stomp on it but the throw back effect isn't what I expected. I've been told that I will lose some of that because the car is running in a taller rpm range.