SC400 vs. Supercharged 745 BMW

[jibby]

This is the section of the forum that talks about steet races and I have a good one to tell that happened several months ago. Ok, I often get street races living in LA near Marina Del Rey, there is this one steet that is about a mile long, no cops, no lights and alot of sports cars drive it regularly. Anyway, I had been feeling very good about the way my car was running of late. I have an sc400 with a little over 400HP or so, with a decent drive train setup, Supra LSD, and a Torque Converter, lowered an inch and with nos, anyway I had previously raced an M3 BMW and beat it, not by much but I handled it, and so I am cruising the Lexo down this street I was talking about, it is night and pull up to the first and only red light entering into this mile stretch. I look over and what do I see? A fat black lowered,tinted, and pimped out new 745 BMW with a tiny NBA logo near the door handles . I look real hard through the tint and I believe it was Lamar Odom of the Los Angeles Lakers. I think nothing of it because I see the athletes and movie stars all the time around here, and I don't think much of the BMW 745 either because I had just smoked an newer M3 BMW just the other day and I know those are faster.

The nos bottle is charged and armed, the light turns green, and I am off. I thought I would show Lamar not to mess with an SC400 like mine, I think I suprised him and I think he did not take me serious, but I have the great start hit the nos and the rears start spinning, and at that point I am just looking into my rear mirror and I know as soon as my tires grip in second gear my car is gone and very hard to beat from like 20mph-50mph that is my power area, anyway, what do I see? That beamer screaming down the road and starting to catch up to me, and he is catching me in my power area too, we get all the way upto about 100mph hour and we had to shut down thank god, but I look over and he was right behind me, and I could not believe it.

I still won the race end of story, that BMW had a serious airforced induction setup on it no dought and was fast as sh_t!!!!!!! I could hear his engine over mine when we were racing it sounded like a jet airplane, and I am running straight through mufflers and bigger exhaust pipes on my SC....

Moral of the story - Just because you think the car maybe stock, doesn't necessarly mean that it is. Late-

 

[jibby]

Hey does anyone know how much horsepower the stock sc400 transmittion and drivetrain can handle before cooking or breaking? I get so many different opinions when I ask this question? I am about to add a few more mods and I am starting to get nervous about the stock tranny, I do have a tranny cooler. Anyone?

 

[cowboy bebop]

Probably as much as a MKIV auto can handle reliably. Around 450rhp, and a hard shift to 2nd, and it's finished.

Eric

 

[jibby]

I assumed it was somewhere in that area of 450-500rhp just like the engine. Do you think the transmittion will fail due to heat or stress, or both at around 450rwhp? What I am trying to find out here is there any advantage to having a tranny cooler on the stock transmittion, and is failure due mainly from stress and not heat as you climb the horsepower latter? I am looking at a box of plastic tubes and some other crap sitting in my livingroom, and they call this a transmittion cooler for the sc400. It looks to me more like a tranny leak waiting to happen in a box. Anyway, I am wondering if I should install or try and return it and get my $200 back? Thanks Eric.......

 

[cowboy bebop]

I mean you can install the tranny cooler, but it's no the heat that causes them to go. It's just raw HP and TQ that make them give up the ghost. It may even reach 500rwhp for a small time but at that point it's not a matter of if, it's a matter of when.

Figure on a SMALL single turbo 2jz, the auto tranny rarely holds for long. I can only imagine how short a time it would hold on a small single turbo V8. One pass and call the flatbed. It sounds like you're at a plateau with you mods until you take precautions to reinforce the driveline.

Eric

 

[jibby]

Well thanks again, you just conviced me to return the box of leaks waiting to happen, and try to get back the $. Your thoughts on changing to larger valves in the same stock tranny or forget that approach and go for the manual tranny transplant?
Man, believe it or not, I like the automatic tranny in traffic and on dates, and driving in general, that way I can play with the radio, MP3 player, and even my girl instead of the stick shift. (opps, maybe a different choice of words next time) I haven't owned a manual tranny car in years since my 300zx TT. Decisions?

 

[cowboy bebop]

The trouble is that reliable automatic trannys in the upper regions of HP become VERY costly and few. You can go with a built Th400 as I mentioned before, but since that a mostly drag tranny, it's not so fun to drive on the street. It'll hold (when built) but it takes all the fun out of driving. Plus the costs ($4500-$8000) are prohibitive compared to the V160 manual. The best thing to do would be to contact someone local with a V160 and ask them to take you out in town to show it's manners. Once you drive, it understand how unbelievable it really is in day to day driving, and HP holding, there's really no other choice.

Eric

 

[jibby]

Wow, bold statement! I will take your word for it the V160 is the choice. Especially coming from a man with four digit horsepower. Thanks for all the info, greatly appreciated.

John

 

[cowboy bebop]

Not a problem man, : )

Eric

 

[jibby]

Hey, One more question before we shut this down, I want to ask do you have any idea as to what the 1994 Supra rear LSD and the sc400 axles, spindles and driveshaft can handle in the way of raw brutal rear wheel horsepower? I never here anything past the tranny's on this subject..

 

[cowboy bebop]

Hi man, the MkIV LSD shouldn't have much of a problem in normal use. and holds up to drag racing well. The SC400 halfshafts snap under HP and hard lauches, but the upgrade is MKIV turbo halfshafts. The drive shaft has to be modified when going to any of the other trannies, (V160, Th400, ect). It has to be a different length, but believe it or not, that's pretty simple to do.

Eric

 

[jibby]

Outstanding thanks.....................

 

[jibby]

Hey, has anyone thought about a powerglide automatic tranny swap, those can handle the hp's and are smoother then the TH400.