rskrause

Loss compared to what? Flywheel-RW? That would be quite consistent with what others see, actually on the low side. But you keep implying that it's a comparison of the TH400 vs. another automatic, which is what people find hard to understand. If that's what you mean, your converter must be loose as a goose, and probably malfunctioning.

Rich Krause

scott ws6

well it was right in front of me, are you calling me a liar. dude I make 600 rwhp and am not new to this , Im telling you what I lost so blow it out your a$$ for saying im lieing. What reason do I have to not tell what I saw.

N20Dave

I don't think Rich is calling you a liar. He's just trying to understand where the loss is occuring. Take a chill for a moment. There's a lot of guys doing tranny swaps reading this post (myself included) and maybe your situation can teach us something.

Getting back to your 89hp loss, the converters had to be different with one being lockup and the other not. That could have accounted for a part of the difference there. What other variables were changed when you switched to the th400? I don't disbelieve you had that loss but I don't think it's comming from the tranny. Something must be affecting your combo in a certain way.

rskrause

I was asking exactly what happened, 'cause what you posted just doesn't make sense to me. Still doesn't. What I am asking is what did you see? What are the two configurations that differed by 89rwhp?

Also, there really is no need to be so insulting and provocative. I re-read my post and don't see anything that a reasonable person would construe as "calling you a liar". I certainly meant no offense, and don't see why you took it that way, so therefore I see no need to apologize.

Rich Krause

Stephen 87 IROC

You're not comparing apples to apples. Yes, you will lose a lot of hp using an automatic compared to a standard transmission. All standard transmissions use a lot less hp than an automatic because they don't have a hydraulic pump in them eating up hp. Stock Eliminator racers will modify the pump so that it has less drag and they also lower the pressures so that the pump doesn't have to work so much. These little tricks reduce how much hp is lost in the transmission.

Compare the TH400 to any other automatic transmission to see how much hp loss or gain there is. Don't compare it against a manual transmission.

Many racers prefer the automatic with the extra hp loss just to gain in the consistancy. Unless you buy a Lenco, you're not going to shift a manual the same every time.

T/A lt1

The guy is saying that he dynoed with the 4l60e and then when he dynoed with th400 he had 89 less rwhp. That is what he is telling you guys. Of course he has a different converter b/c you had to change converter when swapping trans but you guys know that. Maybe he dynoed the 4l60e with the converter locked Either way he lost that much power but it maybe due to wrong conv. driving thru conv. alot of variables could happen. RSKrause how much rwhp did you lose on your first trip to the dyno with your trans swap 250rwhp? Didn't you say you made in the mid 400'srwhp? It is b/c you had the wrong setup and his setup is probably less than optimal. My .02 so stop fighting

rskrause

'xactly, that's why I was asking what precisely he meant. Just trying to increase me knowledge base. I suspect that one of the two things you mentioned (or both) is what happened. That's why I posted those as the likely culprits. A loose converter or that somehow the converter was locked on the 4L60E.

Dyno tests on cars with very loose converters are pretty much useless for measuring hp. As you mentioned, with a 5,000stall I lost in the range of 250rwhp! We recently tested a Camaro with a 555ci BBC with all the good stuff including 20psi from a giant Procharger (F2 if I remember right). It dynoed in the mid 500's. Cars runs high eights, but the very loose converter (~5,500 stall) makes the hp readings inaccurate. The testing is still useful as a tuning tool in a variety of ways, just not as a way to compare hp of one motor to another.

Rich Krause

scott ws6

I dynod with 7 psi on a d1 and made 516rwhp convertor locked with the 4l60e. then I went to the hughes 400 and dynod 89 hp less with a non lock up convertor. I know made 595 rwhp and 574 tq through that same T400 with the sme non lock up convertor.

rskrause

Now I understand. Thanks. It's the converter, not the tranny as I suspected. Which converter are you running? Did you try both at the track?

I am asking because I am going through some converter issues. When we dynoed my car with a 5,000 stall it made a pitiful ~450rwhp (down >200hp compared to an M6). I didn't try it at the track, though I drove it on the street (not too bad, surprisingly). In retrospect, it would have been interestng to see what it did at the track. It's been "adjusted" and I am going to be trying it soon. Now it's supposed to stall at ~4,000.

Rich Krause

Injuneer

At the risk of being told to blow it out my a$$...... I'm still confused (and maybe that's my problem).....

OK....

4L60E = 516rwHP

OK.....

4L60E = 516rwHP
TH400 = -89rwHP (loss)
============
TH400 = 427rwHP

But that would be:

4L60E = 516rwHP
TH400 = 595rwHP
============
TH400 = +89rwHP

And, I posted the data for a manual vs. an automatic only to show that with an extremely efficient drivetrain (as in T56 in direct drive) the loss of going to the loosy goosy TH400 was only 70rwHP. So it seemed difficult to understand (note - I did NOT say "difficult to believe") why a 4L60E to a TH400 would be 89HP.

Not calling anyone a liar.. .only trying to rationalize my experience vs. yours, which I am sure is what Rich was trying to do.

Tekprodave

Here is some info that might help:

4L60E...good to about 750HP with the right builder but no good t-brakes available at this time.

2004R...Good to about 980HP again with the right builder and good working t-brake

TH400...1000HP+ and t-brake

The 2004R is my choice for the have your cake (Overdrive) and eat it too (t-brake) and the best builder for these is PTS Xtreme Transmissions. PTS Xtreme web link

Others:

4L80 too damn expensive and weighs a ton
TH350 not as strong as TH400 so why bother

LT1 1980 malibu

To add to this its my understanding that the only 200R4 to get is a BFR? these would be monte SS and GN transmissions only..Can someone enlighten me here?????Far as i know its just a better servo asembly, am i missing something..Yards sell them for $250 as quoted by the holender program at my job..A700R4 cost a lot more than that..

There comes a point where overdrive is a bad desision on a high power car..The 700R4 vurs the 200R4 i would say hands down 200 is the winner..The gear spread isnt as extreem as a 700 and in a high power car that 3.06 1st gear makes for an even hairyier car out of the hole..But if you makeing more than 600HP at the flywheel id look at a taller tire and a 3spd auto (TH350 wouldnt be the 1st choice but id still consider for a double digit car)

Enter the use of a powerglide..Reccomened for cars under 3000 lbs mainly..Persoanlly ive used one at 3450 but keep in mind that this was a mild ford big block..1.28 short times were a handfull so swapping out the C6 made sense..

I see a lot of use of the chassis dyno lately..Great for tuning street cars but if your building a sereous race car then stick with the tried and true engine dyno..Its harder to get an efi setup working there but the tune will be rock solid in the end..Play ith the converter as part of teh chassis..

scott ws6

injuneer- I made the 595hp with a f1 and 15 psi. whe I made 516 it was a D1 and only 7 psi.

Tekprodave

True, the best one to get IF you can find one is out of the 89 turbo TA. It make the conversion easier because of the electronic speedo sender. (I'm not sure really what it's called.) But IF you can find one they will cost a bit more. Who needs a speedo at the drag strip anyway? The 200 does have nice gear ratios and it will be my choice when I break my 4L60E.