[project] 405 Mi16 Drift/track Car

[AlexN 7]

Right people I need your advice on a few things.

 

Me and a friend are going to build a rear wheel drive 405 Mi16. I know it's probably going to be a bit expensive and an engineering challenge but I really want a track/drift car, I have some money to spend and I love Mi16's. But I want the fun of a rear wheel drive car.

 

So the plan is to buy a fwd Mi16 and strip it. Seam weld the chassis, weld in a larger transmission tunnel, and get a full cage welded in. Once that is done the tricky bit starts. I have a complete spare 4x4 drive train, and what I intend to do is get the transfer box modified to deliver all the torque to the rear. I'll also get the transfer splines shaft uprated as eventually I want to turbo the car so I want to make sure it can cope.

 

I want a fwd donor car as it has normal rear suspension, (unless the mounting points for the fwd rear beam and 4x4 rear sub-frame are the same - can someone tell me if they are, as then I will look for a 4bie donor car). I can't see the hydraulic suspension of a 4bie being reliable on track, and it adds a lot of weight. The first question is, can I fit 4x4 rear hubs to the fwd car? Also I would need to build a custom diff mount, but I'm not sure if the standard torsen diff off the 4x4 can cope with 200+ hp? Can anyone tell me what it is rated up to? I guess rebuilding this will be expensive, so was thinking of getting a ford or similar rear diff and get custom drive shafts and prop to fit.

 

I want to get the car weighing less than a ton, preferably nearer to 900kgs, which I hope will be possible.

 

Like I said I am serious about doing this project, and we'll hopefully have the donor car bought and stripped this week. I'm expecting it to take about a year to complete, and having two people to share the work/cost should make a less painful experience. I will overcome the engineering difficulties, but if anyone can offer any advice up front it would be much appreciated.

 

Thank you all!

[Guest turbolag]

Buy an already RWD pug (504, 605 etc) and stick an Mi engine in there. Why reinvent the wheel, so to speak?

[AlexN 7]

Buy an already RWD pug (504, 605 etc) and stick an Mi engine in there.  Why reinvent the wheel, so to speak?

<{POST_SNAPBACK}>

 

Why? Why not, it won't be a 405 if I do it to something else! I'm probably going to get a Sierra Cosworth rear diff and use that. Modifying the drive shafts should be straight forward enough.

[ryan13961345402285 1]

Hardest part is making sure EVERYTHING is accurately aligned otherwise the car will be very tricky to drive. I built a RWD Mk2 Fiesta a few years ago and it was a curse of a job tbh.

Why not use a 405 4x4 shell and replace the rear axle with something else (Ford Atlas for example). The 4x4 will already have a transmission tunnel, and since you have to build everything in the rear end from scratch anyway it would save alot of hassle

[AlexN 7]

That was my first thought, however 4x4's are rarer and generally cost more. If anyone is selling one for a good price then I'm interested! Of course I could use my car that is currently fully stripped and in bits and buy a fwd to use on the road. Infact that's such a good idea I might just do that!

[KRISKARRERA 2 1 Cars]

Sounds like a project for Cybernck, it's less complicated than making a twin engined 205 mi16!

[AlexN 7]

Had a good think today, and decided it's pointless buying another car when mine is ready for the conversion. I'm going to start asap on the shell and get that prepared and get some quotes for a custom weld in roll cage.

 

First thing to buy will be a sierra cosworth diff and drive shafts and a standard Mi16 rear beam.. Rebuild the diff and then get a custom diff mount sorted and work out how to fit it all to the shell.

 

While this is going on start on the engine. Not sure how much to do but it does needs a total rebuild. Going to get the whole bottom end blue printed, but what is a standard bottom end good for, 8000rpm? I want to get the most out of it I can normally aspirated, so throttle bodies will be fitted. How much difference does a big valve head make compared to a well ported standard head? The hydraulic lifters will be replaced with solid, and an aggresive cam fitted (maybe one of Peter Taylor's St.3's).

 

For track use any recommendations on suspension? There are a few after market kits I've found, I assume the Spax PSX kit is amongst the best out there? Is it worth fitting thicker anti-roll bars front and rear seeing as this is going to be a pure track car? Brakes will be 406 Coupe brembo's on the front and maybe a hydraulic handbrake kit.

 

I reckon a year tops for the whole build. I'll be able to invest a lot of time on the project in the new year, but will make a start in the next few weeks.

[stuart.m 0]

I dont have enough technical knowledge to advise on very much, but just wanted to say its a great plan I think it'll be awesome when it's done. stick with it

[Guest turbolag]

Why not, it won't be a 405 if I do it to something else!

It won't be a 405 by the time you've chopped half it's bottom off and welded in the new tunnel. You'll need a lot of bracing on the rear too if you're gonna start putting transmission forces through the rear of the shell - it's not unknown for 405s to crack where the C pillar meets the roof as it is, so imaginge what it's gonna be like if you don't radically reinforce the shell.

 

The 504 is dimesionally very similar to the 405, and in it's day the Ti was regarded in much the same way the Mi16 is now - a fast, tidy handler. I could understand it if you were making something radically different, but I can't get my head round you wanting to essentially recreate something pug were doing back in 1969.

[cybernck 402 1 Cars]

i think it's a cool idea , however, being primarily a FWD car (modified to 4WD like yours),

i think it would be much better starting off with a RWD car and a proven one in drift too

(Nissan 200SX or BMW E30).

 

but if you do decide to modify your 405, i will try to help out where i can .

[AlexN 7]

Your all probably right, I would be better of with a rear wheel drive car and go from there. But! I want to make a unique 405. Starting with a 4x4 shell (which I am now doing), the modifications to get all the drive to the rear won't be huge.

 

Thanks for the offer of help cybernck, I'm sure I'll have a load of questions once i start, which will hopefully be this weekend!

 

I work for a world renowned engineering company, so I have the kind of facitilites and expertise at my disposal that most people can only dream about. Prepping the shell and making a diff mount will be pretty straight forward.

 

I'm going to have to start getting some photos up on here!

[Jer309GTi 3]

I've thought about this myself as a very slightly possible project for the future. I was just thinking of getting a base model 405, and a 2.0 sierra and putting the sierra engine/transmission/rear suspension on the 405. Then if it's any good, stick a Cossy engine in there

 

It will never materialise, but it's good to dream

[petert1345402284 0]

I can't see the hydraulic suspension of a 4bie being reliable on track, and it adds a lot of weight. The first question is, can I fit 4x4 rear hubs to the fwd car? Also I would need to build a custom diff mount, but I'm not sure if the standard torsen diff off the 4x4 can cope with 200+ hp? Can anyone tell me what it is rated up to? I guess rebuilding this will be expensive, so was thinking of getting a ford or similar rear diff and get custom drive shafts and prop to fit.

 

Why is the hydraulic suspension going to be any heavier than two torsion bars and an ARB? I'd actually suspect it would be lighter. Especially with the aluminium 4WD hubs.

 

To answer your more fundamental question, use a 4WD to start with. Why not just leave out the front diff/axles and fit a locked centre diff? Fit a turbo and and away you go! If you have too much wheel spin, change the CWP. The torsen diff is the strongest part of the car. The same diff was fitted to 505 Turbos. I know of someone who has one behind a V8.

[AlexN 7]

Now this is the kind of info I needed! I have decided that my 4x4 will be the donor car, and basically do as you say. The only worry I have is with the reliability of the 4x4 rear suspension on track. Has anyone had any experience with it?

 

Turbo charging it has crossed my mind. How cheaply can you turbo and Mi16?

[cybernck 402 1 Cars]

some pics of the 4wd rear suspension blasted (at the bottom of the page):

 

http://projects.205gtidrivers.com/acox99?page=6

 

it should be quite good on track as it's easy to uprate it with a harder sphere .

 

 

is your Mi16x4 engine a DFW (9.7:1)?

 

if the answer is yes, then it's relatively cheap to turbocharge it!

[AlexN 7]

It's a 1990 XU9J4 D6C (the higher compression model). Surely all I will need is a decompression plate and then it too will be quite straight forward, or am I missing something? And how cheap is relatively cheap?

 

I can get a custom manifold and downpipe made at work, looking at this link has given me ideas! http://www.aussiefrogs.com/forum/showthrea...?t=45211&page=2

 

 

I've got two complete rear beams, one on the car and one spare. I'm going to overhaul the best of the two and keep the other for spares.

 

This weekend I finish stripping the shell and engine down.

[triple_a_motorsport 0]

I would also say that surely a torsen diff would be better than standard for drifting? for the shear fact that both are kept the more or less same speed which is what you want? if just one is spinning then you will just be sitting there not drifting? if you spent a bit of money it could be uprated to take more, but i'm sure the rear diffs on the 405mi16X4 aren't that bad anyway its the front splines that are more of the trouble.

[petert1345402284 0]

I would also say that surely a torsen diff would be better than standard for drifting?

 

That's my point. Mi16x4's have a torsen diff as standard.

 

Just make sure you have double diaphragm sphere and get it pressurised to 55 Bar. Standard is 40 Bar.

[cybernck 402 1 Cars]

only rear diff is Torsen, while front/center diff is visco-coupling.

 

btw, the rear diff is not a classic RWD differential with final drive ratio,

but the final drive is still in the gearbox, just there's a shaft coming

out of the gearbox and into the transferbox.

 

it should be possible to trow out the visco-couple system and make

the transferbox deliver 100% torque to the rear wheels, but it's a

very complex unit (the transferbox) and you'll have to know what

you're doing.

 

 

you need to make the exhaust manifold either way, but the rest would

be much easier and cheaper with a DFW engine with a knock sensor.

 

for instance, on DFW you don't have to remove the head or lower the C/R,

run low boost (<0.5 bars) with a cheap and widely-available turbo and

you can simply add a 5th injector and it should all work ok and give you

200-220 bhp and no loss of off-boost performance.

 

while on D6C you need at least a spacer plate (or ideally low-comp forged

pistons), stand-alone management with larger injectors and a more-capable

turbocharger, but ultimately you can reach up to 300 bhp without problems.

[AlexN 7]

I've been looking at DP-Engineering, and it appear as though they sell good kit. Has anyone had any experience with them?

 

As for the transfer box, I know it is going to be the trickiest part of the whole conversion (and ultimately the key to it being a success). I'm not sure it's a job I can do myself, so I'm going to find a gearbox overhaul specialist and let them have a go. Just got to find one now...

[cybernck 402 1 Cars]

i know DP-eng guys - they've started it all as enthusiasts but taken it to a highly professional level!

 

from what i've seen, their work is top notch and kits are very well thought.

 

if a bit expensive, but you get what you pay for .

 

 

as for the transferbox mod, i think some Cavalier/Calibra 4WD experts might be of help .

[Jer309GTi 3]

Would a supercharger not suit the Mi engine more? The 'charger would give you lots of low down torque and you would then have the power higher up the rev range when it comes on cam. Or wouldn't it work like that?

[AlexN 7]

I've been emailing around looking for companies that can modify the transfer box, and this is one reply I got from a guy at www.gearboxman.co.uk Is what he says true? I want to run close to 300bhp so I need to know the transmission isn't going to need constant tlc.

 

Hi Alex,

The rear wheel drive part of your transmission assembly was an addition

to the original front wheel drive layout and was never designed to take

all of the power load in isolation.

To be honest we're not sure the system you're proposing would ever cope

for long with the standard power output and are pretty sure it'll not

cope with 300bhp.

The best advise we can offer is to recommend you rethink this and work

towards a more conventional rear wheel drive layout.

Regards,

Stuart.

[AlexN 7]

I've been emailing around looking for companies that can modify the transfer box, and this is one reply I got from a guy at www.gearboxman.co.uk Is what he says true? I want to run close to 300bhp so I need to know the transmission isn't going to need constant tlc.

 

Hi Alex,

The rear wheel drive part of your transmission assembly was an addition

to the original front wheel drive layout and was never designed to take

all of the power load in isolation.

To be honest we're not sure the system you're proposing would ever cope

for long with the standard power output and are pretty sure it'll not

cope with 300bhp.

The best advise we can offer is to recommend you rethink this and work

towards a more conventional rear wheel drive layout.

Regards,

Stuart.

<{POST_SNAPBACK}>

 

Reading peterT's post above about it being used on the 505, i'm really not sure I believe what this guy is saying...

Edited October 10, 2007 by AlexN

[Guest piran21]

is your Mi16x4 engine a DFW (9.7:1)?

 

if the answer is yes, then it's relatively cheap to turbocharge it!

<{POST_SNAPBACK}>

 

 

Is it really cheap? Care to expand?