M40 292 Piper Cam, Remap and lightend flywheel.

[Alex]

Would i need to do any head work to use a 292 Ultimate fast road cam in an m40

http://www.pipercams.co.uk/pipercams/ww ... facturer=5#

Would the car need to be properly remapped for it to work best. also would a lightened flywheel with it make it zip along nicely. i plan on converting it to manual over the next few month too, would a lightend flywheel be worth while?

Diff wise its got a 4.45 would a 3.91 be better with the above mods?


Yes i know its a waste of money, and not good bang for buck but i dont want to remove the original engine its too good. i want to make the best of what ive got. i dont want to remove the 40k fully documented m40 engine

if i can make it a little more fun to drive than a boggo 318i i will be happy

[RyanBax]

Hi Alex,

I would not go for such a long duration cam on a standard M40 - the compression ratio is too low at 8.8:1. You will lose low and mid-range power as well as gain a rough idle. Further, to get a long duration cam to work on a motor, one needs to flow the head and install larger valves. It's a do it properly or money waster situation.

To answer your question, a remap would optimise the timing as any changes to the motor need to be accounted for by a new mapping to achieve the best gains. Otherwise, it would probably work alright without a remap, but not reach its design goals.

The flywheel conversion would probably be the best bang for buck conversion available to these motors. The standard flywheel is approx 9.9kg on the M40 motor. This conversion is common on the M42 motors and has a large effect upon acceleration. As you are aware, when you convert to manual, you will have to buy a manual flywheel so why not buy a lighter version.

As regards the diff, definitely do not go to a longer final drive, especially if you install a long duration cam. The shorter final drive will allow the motor to rev up much better. Installing a long duration cam pushes the power band further up the rev range which means your power will only really come on at higher revs and feel flat below that. You need a short final drive so that you can rev up quickly, otherwise you will be stuck working the motor hard just trying to get the revs up. Your acceleration will be stunted in other words.

Other mods you could look at are doing a good porting job on the head, branches, cam and definitely the manual conversion if this is to be done. The M40 motor is not a racer, and these types of mods are not going to increase torque significantly. But if you are going to go with a cam, go for a shorter duration cam with more lift, it will be more satisfying.

Here is a link that will give you good insights: http://www.pumaracing.co.uk/index.htm

Hope that helps

[e301988325i]

+1

i dont want to remove the original engine its too good. i want to make the best of what ive got. i dont want to remove the 40k fully documented m40 engine

Enjoy it for what it is or swap the engine out for a 6 cyl and store the 40k turd. The M40/M42 is never going to shift an E30 well without forced induction or serious capacity increases, which compared to an engine swap can't be done on the cheap.

[Alex]

Hi Alex,

I would not go for such a long duration cam on a standard M40 - the compression ratio is too low at 8.8:1. You will lose low and mid-range power as well as gain a rough idle. Further, to get a long duration cam to work on a motor, one needs to flow the head and install larger valves. It's a do it properly or money waster situation.

To answer your question, a remap would optimise the timing as any changes to the motor need to be accounted for by a new mapping to achieve the best gains. Otherwise, it would probably work alright without a remap, but not reach its design goals.

The flywheel conversion would probably be the best bang for buck conversion available to these motors. The standard flywheel is approx 9.9kg on the M40 motor. This conversion is common on the M42 motors and has a large effect upon acceleration. As you are aware, when you convert to manual, you will have to buy a manual flywheel so why not buy a lighter version.

As regards the diff, definitely do not go to a longer final drive, especially if you install a long duration cam. The shorter final drive will allow the motor to rev up much better. Installing a long duration cam pushes the power band further up the rev range which means your power will only really come on at higher revs and feel flat below that. You need a short final drive so that you can rev up quickly, otherwise you will be stuck working the motor hard just trying to get the revs up. Your acceleration will be stunted in other words.

Other mods you could look at are doing a good porting job on the head, branches, cam and definitely the manual conversion if this is to be done. The M40 motor is not a racer, and these types of mods are not going to increase torque significantly. But if you are going to go with a cam, go for a shorter duration cam with more lift, it will be more satisfying.

Here is a link that will give you good insights: http://www.pumaracing.co.uk/index.htm

Hope that helps

Awsome, so the fast road will be the better one then.

So i convert it to manual and keep the short 4.45 diff with a lightend flywheel, remap and Cam

sounds like it will be a fun motor to rev on the twistys

piper claim 10bhp would you take that with a pinch of salt like a remap ?

anything else worth doing, i was looking at a 4 branch manifold from ebay.de however i'am guessing the steering linkage will get in the way, do you recon a danthe one would avoid that issue.

i know i'am not going to burn people of at the lights i just dont want to ruin it by removing the original engine. and have something thats fun to drive and not to far behind IS pace if not the same

[rix313]

Yes i know its a waste of money, and not good bang for buck but i dont want to remove the original engine its too good. i want to make the best of what ive got. i dont want to remove the 40k fully documented m40 engine

I appriciate what you're saying here, but a cam and remap and 4 branch and lightened fly wheel will easily easily outweigh the cost of an M42.

[Alex]

Yes i know its a waste of money, and not good bang for buck but i dont want to remove the original engine its too good. i want to make the best of what ive got. i dont want to remove the 40k fully documented m40 engine

I appriciate what you're saying here, but a cam and remap and 4 branch and lightened fly wheel will easily easily outweigh the cost of an M42.

Yep, i allready know that

[RyanBax]

Hi Alex,

Ignore everyone else, they might be right but we are just having fun. We are not out to impress the forums.

As for my car, I ported the head and installed 43mm valves as opposed to the standard 42mm valves. I had a custom branch made up that winds its way on either side of the steering link. The link has to be removed before removing the branch - its a bit painful but not the end of the world. It was remapped, but after a few years it started smoking and pinging so I had it removed to regain the standard, slightly retarded timing. The dyno stated that torque had risen by 15NM (divide by 1.36 to get pounds/square inch) and horspower by 20HP. An upgraded cam would have worked well with the head mods. I have since overhauled the motor and hope to supercharge it in time.

I would definitely go with the shorter prifile option as your car will be more driveable. The fast road cam will be a better fit for your car as you don't want a donkey at low and medium revs. The ultimate road cam is more for rallying and only useable with other serious mods to the head and block such as increasing the compression to above 10 at least. You will regret the rally cam in time as you tire of it. Torque is what provides driving enjoyment.

As regards the performance improvement, the 10hp gain is probably a bit ambitious. With a tune and branch you may get closer to it. I can't say as I have not done these specific mods alone. I also can't comment on the e-bay branch as I have not idea for its quality.

The thing about motors is that one mod by itself is often useless, but mods in conjunction with other mods that work together are beneficial. The best thing you can do for your car will be the manual conversion with lightened flywheel.

Let me know how things progress.

[rix313]

Ignore everyone else, they might be right but we are just having fun. We are not out to impress the forums.

What?!?!

[RyanBax]

Yeah, that was a bit stupid, probably misleading.

The circumstances dictate that the existing motor is in good shape and that replacing it with another motor (say another m42) could bring new problems. A mate of mine converted to an m42 motor and 5 months later was told that it needed an overhaul.

He ended up selling the car because he could not afford that. Granted, the idea of converting to another motor would in the long run giver better gains at a more affordable cost.