Sort of have to make a fairly quick decision on which would be best for an anticipated circuit race car project, someone wants to buy my LS. For the price of the LS I could get a good M113 with trans and more. The choice for a LS transmission would be a Ford 6R80, both would get aftermarket controllers. As usual I'll probably ignore any advice :wink: but you never know, someone here may have considered going down a similar problematic track.

 

Hi 260 DET

Maybe you just got lucky. An LS conversion would have been very complicated, the M113 is they way to go. You can use the M113 with the existing auto or convert it to a 6 speed manual. It will all bolt straight in. An M113 conversion will be very similar in weight to the M112K supercharged V6 and will have a slightly lower centre of gravity. The 5.4L NA engines are getting hard to find here, so a 5.0L would probably be the quickest way forward. The best way to get extra HP out of the 5L would be some cams and a matching tune, to try and get and extra 1000 rpm out of it (it should be OK for 7000rpm). You could run it all from a stock ECU (and stock TCU if you go with the auto). I can make you a suitable ECU (and TCU if you use an auto). There's no need to change existing transmission to a V8 unit, but if you get one cheap with the engine, then that's even better.

 

Ah Andrew, you are the man I've heard good things about. The idea with the LS is to use it's existing Haltech ECU and a US Shift TCU for the 6R80. But the bell housing I thought was available does not exist.

With the M113 I was thinking of a Link ECU with the stock loom as I want to get rid of the Mercedes electronics, too limp mode prone for a race car. What ECU do you make, is it stand alone and does it connect into the stock engine harness? If I went the M113 way would it's trans be better assuming that it was in good nick?

 

If you are drag racing, the automatic will be the way to go. If you are circuit racing, then a manual 6 speed is going to be pretty hard to beat. If you are drag racing, you want to hold out and find the supercharged M113K. If you are road racing, then the normally aspirated M113 will be the way to go.

 

I agree with Neil's summary of the combinations. I can modify OEM ECU's to operate the M113 or M113K with auto or manual, and connect to the stock wiring harness. An aftermarket ECU will not run the engine (and integrate with the car) as well as the OEM unit can and you could still keep all the factory safety stuff (eg. ABS and Stability Control). If you went with an M113, I would just modify the car's original ECU. I can get rid of anything that would generate limp codes or limit the torque, or rpm. Where are you located?

 

I'm not far from you Andrew, Warwick, 4370. I do want to use an auto for circuit racing, used a shift kitted GM 4L80E behind the LS3 controlled by a Powertrain Control Solutions TCU and it shifted great, only problem was no engine braking. Probably best to move this conversation to pm but for anyone else interested here a couple of questions about your complete set up. I assume that the TCU will not be user tuneable so how do you supply it pretuned? I'm not fussy but do require strong engine braking and fast snappy shifts. As for the ECU, what about user tuning if, say, the cams are upgraded? There is a good dyno tuner here. Thanks and cheers, Richard.

 

There is a guy on youtube who did a series on putting a LS motor into his crossfire. For the most part, it looked like a typical LS everything swap. Its funny how you can literally LS everything.

 

Hi Richard

Stand alone TCU's are good, but they're best for retrofitting transmissions with engine combinations that never came OEM. For example, fitting a newer transmission onto older engines in older cars. Their main problem is that unless they can integrate with the ECU, they can never coordinate torque control with the ECU, hence your engine braking problem. Mercedes uses engine torque management with the 722.6 so it can change gears quickly and not overstress the engine or transmission, and it can all be adjusted.

The TCU and ECU are not user tuneable, but they are highly tuneable, if you have the right equipment and knowledge. Your requirements for the transmission shifting are straight forward, so I can supply something pretuned (but custom made for your exact setup) that will do the job. It will change gears exceptionally well; however, there's no way I can ever make it change gears as quick as a dual clutch transmission.

If you don't do any major mods to the engine then I'd have some existing ECU tunes that would give you extra HP. They will adapt to reasonable increases in intake air flow and improved exhaust flow (so fit a decent air intake and exhaust system). If you want to do some ECU tuning on a dyno then I could probably come up and change the maps further (while you're on the dyno), but I don't think you'll get too much extra without cams (allowing it to get in some more fuel & air and rev more).

I've had cams made by Tighe Cams, who are close to my place. They make new cams up from scratch and I'm sure they've still got some spare billets left over after the last set I had made. The main problem with just regrinding the Mercedes OEM cams is that the lobe separation angle isn't optimal for the best performance, so without without casting new billets with a different angle, you can never fix it. I'd be interested in doing some before and after dyno tuning just to see how much we could improve an NA engine.

Send me a PM and I'll send you my phone number so we can talk.

 

Thanks for the very informative post Andrew which is sufficient for me to decide now what to do as far as what to sell and what to buy. The 6R80 bellhousing quest seems hopeless so a M113 is the go. I'll pm you when things have settled down a bit..

 

If you're wanting more gears, then another potential option will be the 722.9 7G transmission. They have been slow on the uptake in the performance world, and add certain other complexities, but the MB world seems to be happy with them, and the extra gears may give you that closer ratio setup you probably would want. Getting it into the car would involve fairly little, in terms of fabrication: New driveshaft and likely some mods to the trans mount. The real trick will be in the electronics. Not sure if Andrew handles the integrated TCU of the 722.9, but there are people who do.

And you probably already know that Dave on SLKWorld is planning a 722.9 behind his 5.0 M113 in a R170.

On a side note, I planned on going the 722.9 route myself, until Andrew worked his magic, and made the 722.6 perform better than the factory ever did in these cars - by a long shot.

 

Hi Neil

I'm keen to see how Dave goes with his 722.9 conversion. Like all these projects, I think there'll be more to it then he expects, but good luck to him.

 

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