Auto - Manual Conversion Recommendations

I'm currently saving to convert my NA Auto into a manual. My eventual aim is to turbo the car to run between 400 and 500hp. Therefore I need a box that can easily handle this power. I've heard he W58 is a bit on the weak side and could easily go bang. I've looked into the BMW M3 E46 SMG 6 speed box. Has anybody on here done this conversion and if so what do they think of it? It's quite an expensive conversion but if it's going to be a safer option than the W58 then would it be sensible to go for this? Or is there a mod for the W58 that can be done to make it stronger? Before anyone points this out, yes I have considered the V160/V161 but unless I win the lottery this box is well out of my reach.

Any advice/guidance/experiences would be greatly received!

Thanks very much!

Brad

The Auto box will hold the power levels you are looking and with a good oil cooler will be reliable as well, if you can not afford a V160 I would question the Turbo route as well as you will be forever spending

Yes I agree. I would love to put a V160 into it but unfortunately I just can't afford the astronomical price they are going for. I've never liked the auto box so I was always planning to make it manual. I'm just stuck with which one. The W58 (cheap, weak but simple) or the BMW M3 conversion (more expensive, stronger, reliable but potentially quite complicated). I can't decide. I was hoping there'd be member out there who had done either conversion and could shed some light on the pros and cons of each, making my decision that bit easier. Can anybody help?

Have you thought about the R154 would easily handle that power.

Yeah I've thought about that one but again, some people have told me it's a fairly complicated swap and the R154s are pretty expensive and getting hard to come by. I actually have an E46 M3 box but it's the rest of the parts for the conversion that are gonna cost a lot of money.

Isn't there an issue getting the speedometer to work with the BMW gearbox? I've seen a couple of conversions but they all seem to rely on GPS rather than proper speed output. That's the thing putting me off from that option.

Yes I've also heard about that issue and that is also something that's putting me off. There seems to be a few pros and cons for each candidate. Just can't make my mind up which one would be best

How far did you get with the auto to manual conversion? I've just picked up an auto and will be fitting the m3 box i already bought for the first car into this instead

Isn't there an issue getting the speedometer to work with the BMW gearbox? I've seen a couple of conversions but they all seem to rely on GPS rather than proper speed output. That's the thing putting me off from that option.

Given his recent auto shifter mod, im sure Burner would be able to produce a little box of tricks that converts the bmw speed signal to something the Supra clocks can understand, but it would likely be a lot of work, and result in significant cost.

Given his recent auto shifter mod, im sure Burner would be able to produce a little box of tricks that converts the bmw speed signal to something the Supra clocks can understand, but it would likely be a lot of work, and result in significant cost.

Thanks mate, I don't see why not, nothing is impossible If there's a wider market for it too then that would bring the overall cost down. I actually take a speed signal feed into my electronic shifter, so I understand how it works, and understand the two different types of speed signals present in the Supra, so I imagine I could convert the BMW box speed signal output into a signal the Supra clock can read. Or I could perhaps add on a separate speed signal reader that then feeds the Supra clock. Loads of possible solutions to the problem the more I think about it tbh.

I know that Lee of SRD has put a V160/V161 in a BMW M3 so maybe he will know how they can interact, I realise that this is the other way round but the principle is the same

Use a Dakota Digital Universal Speedometer Signal Interface to convert between an independently placed speed sensor to supra speedo clocks.