Author Topic: M42 mods (what's the potenital) (Read 8414 times)

bacdoc · « **on:** September 05, 2011, 01:34:39 PM »

Before I seriously consider a swap, what's the max the M42 can safely handle and what do I have to do to get there? I hear they are not very boost friendly. So new head, cam, .... that about it?

bflan2001 · « **Reply #1 on:** September 05, 2011, 02:17:24 PM »

from what i'm reading they are very boost friendly, except for the high compression. but the forged crank & rods, piston oil squirters & free-flowing head are all great for forced induction..just throw in some low comp pistons and boost away!

bacdoc · « **Reply #2 on:** September 05, 2011, 02:28:12 PM »

If I'm breaking it down to the piston's I'm not wasting my time putting it back together. I can do a swap probably cheaper and faster.

DesktopDave · « **Reply #3 on:** September 05, 2011, 03:00:14 PM »

I love how light these cars are...I'd start with removing as much weight as possible. But if you're looking for power do a swap. It'll change the handling a bit for the worse but you can pretty much double your power with an S52.

Best you'll do with M42 bolt-on's is maybe 10% gain unless you go for boost.

bacdoc · « **Reply #4 on:** September 05, 2011, 03:06:40 PM »

I was afraid of that. Mine is in such good condition I hate to strip it really. I might sell it and just look for an already setup 325...

Hey-u · « **Reply #5 on:** September 05, 2011, 09:26:34 PM »

Add SC or turbo for around 200 whp with out doing much more. At more hp you start thinking about the 240 trani and small case rear end. 200 is nice amount of hp and the car stays lite.

MikeDE · « **Reply #6 on:** September 06, 2011, 01:45:56 AM »

Quote from: Hey-u;106556

Add SC or turbo for around 200 whp with out doing much more. At more hp you start thinking about the 240 trani and small case rear end. 200 is nice amount of hp and the car stays lite.

^This. No need to crack anything open. Just keep you eyes peeled for a kit for sale.

Actaully, there is a guy on E30zone.com(UK) that has a full m42 Rotrex kit f/s with Everything except a chip/tuning. Here is the ad:

http://www.e30zone.net/modules.php?name=Forums&file=viewtopic&t=205121&highlight=rotrex

But if you have no acct on E30zone.com, here is the ad without pics:

Quote

As hard as this is to do, I feel it's time for me to sell this. I’ve got a few ideas about what I’d like to do next year and they don’t involve or allow the use of forced induction so I am now looking to sell my M42 Rotrex kit.

I have been slowly working on this for the past 2 years. As and when money could allow, I did a little bit of work waited for more money, did something else, so on and so forth. I am and have been very fussy with this on what I’ve bought and where everything has been routed. Doing it this way has meant that I have only bought and used top quality parts and everything has been thought about and planned.

Included:
Rotrex C30-84 super charger
100mm and 95mm pulleys (These are �65 each from Rotrex)
Appletree M42 Rotrex super charger bracket, spacers and bolts
Alternator relocation plate, spacers and bolts
Aluminium intercooler
SFS silicone pipe work
Aluminium pipe work
Forge super size recirculation valve
Rotrex oil reservoir, filter and pipework
Mocal oil cooler with brackets and rubber mounts
1L Rotrex oil unopened
Machined crank pulley, spacer and crank nose spacer for charger belt
PAS pump pulley spacer
PAS crank pulley spacer
Adjustable fuel pressure regulator
Uprated injectors
+loads more bits and bobs

The super charger came from a car company I used to work for and has done very little running.

I personally cannot tell you how much power this produced as I never got the ECU and had it running. In standard form the engine should easily produce 200bhp and with some engine work the sky is the limit, Appletree got 280bhp from his.

Getting the ECU was the final stage in this, you could argue why get so close then sell but my heart isn’t in this any more, I’ve enjoyed it, but I want to race this car next year and need more race focused parts for the car.

I very much prefer cash on collection. The price is �1500, I’m not in a manic rush to sell it but I will consider offers. Bear in mind that a brand new Rotrex kit is �1700+ and this is just for the charger, oil cooler, pipe, reservoir and oil let alone all the rest.

I am happy to offer my help and advice on fitting it and anything else. I can’t offer any warranty on it as I bought it second hand myself but as stated above, it has done very little running and at great expense all aux parts are the bits that Rotrex supply which Rotrex demand for warranty claims.

You may be able to use some of this stuff on an M40 as the mounting points are all the same.

Any questions please ask.

keflaman · « **Reply #7 on:** September 06, 2011, 06:34:23 AM »

^ So that's $2734.00 at today's exchange, plus shipping. Is that a good price?

bacdoc · « **Reply #8 on:** September 06, 2011, 06:43:58 AM »

For that kinda money I would do an LSx swap. :lol:

MikeDE · « **Reply #9 on:** September 07, 2011, 04:47:50 PM »

Quote from: keflaman;106563

^ So that's $2734.00 at today's exchange, plus shipping. Is that a good price?

A new DASC, when one could get them, costs in the neighborhood of $3700.

This is a ROTREX, intercooled, w/ a dedicated oil cooler....all you need is dyno-time/tuning. If I had the loot, I would have snatched it up already.

Quote from: bacdoc;106564

For that kinda money I would do an LSx swap. :lol:

Not really....

DesktopDave · « **Reply #10 on:** September 08, 2011, 10:30:57 AM »

I'm all for keeping the car like it is (just a few mild mods) & getting an M20 to play with. I'd suggest a COP kit, updated 19# injectors and the hose delete mod. I've done them, they're great for the car. I'm eventually planning on a fan delete, MarkD 93 chip, M40 or Valeo single-mass flywheel and a Z3 torsen diff down the road. I'm also thinking along the lines of a WBO2 and updated electronics for my somewhat ratty sedan.

Look for an '88 (super) eta and toss an M20B25 cam, valve springs, electronics, DME & manifolds on it. Easy 200hp with a chip. PM me if you need details.

That is a good price, if only the dollar wasn't so weak! I saw that one myself...it will need a bit of brains and work to get it just right but it's the highest quality stuff. Alternatively, you could pull the parts off compatible cars & weld the mounts/manifold/drive belt. Way out of my expertise though.

e9nine · « **Reply #11 on:** September 08, 2011, 08:02:09 PM »

As mentioned, just do the simple stuff and keep up with the basic maintenance till you can pick a certain direction.

Do not factor $ to hp with these cars, there's no such thing as 'cheap power'

Cheapest fun Equation = up to date maintenance, sticky tires, good suspension and auto-x or track days if that's your fancy.

Donkeyshins · « **Reply #12 on:** September 24, 2011, 12:56:34 AM »

Jim Rowe at Metric Mechanic bores & strokes the M42 out to 2.1L and gets about 210HP from it...of course, you're looking at $6.5k or so, but given all that MM does to the engine, it'll probably last until the oil wells go dry.

-D

p.s. And yes, I'm going to get one someday if I can convince my wife to let me spend that sort of money on a 21-year-old automobile.

DesktopDave · « **Reply #13 on:** September 24, 2011, 07:51:03 AM »

LOL, I'm in the same boat...I keep telling her that it's cheaper than a new car, will certainly last far longer, is more fun, etc. I see it as an investment...she sees it as boyish enthusiasm. While she's most likely right, negotiations remain at an impasse.

I'm still recommending getting an entire second car for tinkering. An e30 is excellent for tweaking and IMHO the M20 327i is a great "bang for the buck" car. Of course an LS1 or an S52 will suck its headlights out but they require much more money, skill & patience. I'm still waiting on the right '88 "super" eta to come my way.

Putting a lot more weight into any M42 ruins the delightful balance of these cars IMHO.

bacdoc · « **Reply #14 on:** October 24, 2011, 09:39:18 AM »

Was on the track at Mid-Ohio last weekend and had a blast. That little car is amazing with minimal suspension mods. However, the lack of power is joy killing. I think I've decided to go the Lotus Exige route this spring so most likely the 318 will be for sale.