Author Topic: Best route to 200bhp? (Read 6371 times)

alunowenjones · « **on:** April 12, 2009, 02:47:11 PM »

Hi,

I'm a new member from the UK. I've just bought a standard E30 318is for conversion into a racing car. My previous car was an Mi16 powered Peugeot 205 pushing 200bhp. Great car, but it was front wheel drive. I'm now looking to tune my M42 to around 200bhp. I can't supercharge/turbo the car as it has to stay in the sub 2 litre racing class. What are you ideas? Ideas on the budget involved would also be greatly appreciated. Thank you.

Best regards,

Alun Jones (Wales - U.K.)

Danny707 · « **Reply #1 on:** April 12, 2009, 02:48:57 PM »

Bore and stroke to 2 liters.

You won't be there though.

alunowenjones · « **Reply #2 on:** April 12, 2009, 03:09:10 PM »

Perhaps I'm not being realistic? What kind of power can I expect with a stroker kit. wikipaedia say..

"long-stroke forged crankshaft from the M47 motor coupled with an overbore of +2 mm will make for a 2.1 L Stroker M42. The 86 mm pistons from a European 3.0 L S50 will produce a high compression, stroker M42 when coupled with the M47 crank"

Jimmy Lewis · « **Reply #3 on:** April 12, 2009, 03:32:23 PM »

200bhp is doable out of 2.0l with an m44 crank. Another key issue is to get rid of the afm and run a map, it may not give you a ton of power but it would make the engine much more responsive. High compression and a set of cams could get you to 200bhp. Search around for stroker builds on here, it has been done many times.

alunowenjones · « **Reply #4 on:** April 12, 2009, 03:46:24 PM »

Thanks Jimmy,

Thanks, that's a good Welsh surname you have! I have a whole year to get the car together (i'm getting married in a couple of weeks and I'm taking a year off from racing) and I know a good engine guy/have acess to a machine shop. I know a lot about tuning Peugeots, but nothing about BMWs!

My plan is approx 200bhp and a very lightweight chasis - just the bare bones within the championship rules.

AJ

DaveM-sport · « **Reply #5 on:** April 12, 2009, 06:22:13 PM »

To be honest, it seems the AFM on the M42 isn't very restrictive until you get into very high RPM such as over 8K or so.

Are you allowed ITBs in your class or are you restricted to run stock induction setups etc.

A 2L M42 running on ITBs, wild cams and a very good flowing head should easily make 200bhp if it's fully geared to racing.

Should drop Tim_s a pm as he is also in the UK and has done the whole 1.9-2.1 M42 and also used ITBs on his and is very helpful. His current 2.1 M42 running with relatively tame cams and a standard throttle body is making 205bhp I think:cool:

Of course, if you have the money lying around, you could buy this and have 260bhp out of the box:D
http://cgi.ebay.co.uk/Bmw-m44-m42-race-engine-s42-replica-from-170-300hp_W0QQitemZ290308370268QQcmdZViewItemQQptZUK_CarsParts_Vehicles_CarParts_SM?hash=item290308370268&_trksid=p3286.c0.m14&_trkparms=66%3A2

alunowenjones · « **Reply #6 on:** April 13, 2009, 07:07:50 AM »

Yes, induction is free with capacity increases if you go the turbo/supercharger route. Carbs or Throttle Bodies would be fine and I would still be within the rules.

Thanks - Alun

Jimmy Lewis · « **Reply #7 on:** April 13, 2009, 12:17:31 PM »

Quote from: DaveM-sport;69967

To be honest, it seems the AFM on the M42 isn't very restrictive until you get into very high RPM such as over 8K or so.

Are you allowed ITBs in your class or are you restricted to run stock induction setups etc.

A 2L M42 running on ITBs, wild cams and a very good flowing head should easily make 200bhp if it's fully geared to racing.

Should drop Tim_s a pm as he is also in the UK and has done the whole 1.9-2.1 M42 and also used ITBs on his and is very helpful. His current 2.1 M42 running with relatively tame cams and a standard throttle body is making 205bhp I think:cool:

Of course, if you have the money lying around, you could buy this and have 260bhp out of the box:D
http://cgi.ebay.co.uk/Bmw-m44-m42-race-engine-s42-replica-from-170-300hp_W0QQitemZ290308370268QQcmdZViewItemQQptZUK_CarsParts_Vehicles_CarParts_SM?hash=item290308370268&_trksid=p3286.c0.m14&_trkparms=66%3A2

As I said, it isn't so much a restriction as it is a delay of throttle response. Think that when you are running a stock afm the barn door only opens enough to allow a specific amount of air into the engine, while a map is a wide open system that simply meters the air. Good luck on your search, and thanks for the self esteem boost.