Engine selection for a track car

[Jean]

Just how bad or good will an m10 turbo work on a track and autox ? Will it have horrible throttle response for autox where you need instant power delivery, it won't matter as much on the track where you could make up the time on the straightways etc ?

I am curious to hear from people with m10turbo and m50/m52 swaps. I have an extra m10b20 block and m10b18 head but this swap will never be smog legal in ca, and will probably cost me just as much as an m50/52 swap.

Thoughts on this ?

[fazio8118]

Just how bad or good will an m10 turbo work on a track and autox ? Will it have horrible throttle response for autox where you need instant power delivery, it won't matter as much on the track where you could make up the time on the straightways etc ?

I am curious to hear from people with m10turbo and m50/m52 swaps. I have an extra m10b20 block and m10b18 head but this swap will never be smog legal in ca, and will probably cost me just as much as an m50/52 swap.

Thoughts on this ?

IMO for a track car your better off going w/ a good reliable NA motor (m50/2 s50/2). I seen more than a few cars run into heat problems during a hard 20min session.

But then again turbos are so much damn fun......

[Rob]

Elaborate on your usage. Is this a dedicated Auto-X car? HPDEs? Club Racing? etc


just saying "track usage" doesn't really have a clear cut answer.

[Jean]

Rob, Sorry I should have done that. It will have to do both Autocross locally for a full season and hpde maybe 2 -3 times a year, no club racing or spec e30 stuff.

I know that autox and hpde are apples and oranges but I would like the car to handle both. I am familiar with both and understand that a car setup for track won't necessarily shine in autox and vise versa.

Quick throttle response , good gearing , balance and power to get the speed on the track (thunderhill) . I guess a combination of many things would be optimal.

[Reynard38]

I've been debating the same thing with a 2.7 stroker. I am leaning towards N/A using all the best components. I just like the repsonse of a N/A motor on the track.

[e9nine]

IMO for a track car your better off going w/ a good reliable NA motor (m50/2 s50/2). I seen more than a few cars run into heat problems during a hard 20min session.

But then again turbos are so much damn fun......

I have seen and heard of m5x/s5x motor go bad during track use as well.

It's all relative to how you drive IMO. No need to go banging on the rev limiter during HPDEs and auto-x do your regular oil changes and radiator flushes, let the car warm up before driving the piss out of it, use good gas, use the right spark plugs etc. This info is generic regardless of whether it's an m10,m42,m20,m5x,s5x, s14. Yes there are some specific items like oil pan baffles, valve adjustments etc which apply to certain specific motors...

With Turbo cars heat is the obvious enemy (needless to state) and the one area you do NOT want to cut corners.

[Jean]

Heat , reliability and smog issue is the reason why I am leaning towards an m50/52 swap. I do tend to drive the car to it's very limits so I want something that will be able to handle full rpm range on regular basis, I will not be happy otherwise..

I was hoping to hear comments/suggestions from the m10turbo/m50 crowd, realibity wise what are the weak points on the m50 or m52 engine ? I would probably want to go with a vanos system with a m50 head as iirc it flows better and will give you better top end ?

I will sacrifice a bit of low end to get the top end that pulls to the redline.

[e9nine]

Getting m20, m10, ,42s to pass smog isn't an issue as inn newer motor $ to $ comparison as you have "more emissions related" things and the motors are still sensitive to certain variables.

The harder you drive the car the more stress you put on the motor and there will also be an increase in "wear and tear" there's a way to use the power of the motor without being destructive.

I know of a turbo m50tu turbo 325iS that has been very soild. Tuning is the key. I'll let others chime in on specific items of concern besides the obvious areas.

[Jean]

Getting m20, m10, ,42s to pass smog isn't an issue as inn newer motor $ to $ comparison as you have "more emissions related" things and the motors are still sensitive to certain variables.

- right, but getting an m10 with a Turbo to pass smog is different ;) especially in california.

The harder you drive the car the more stress you put on the motor and there will also be an increase in "wear and tear" there's a way to use the power of the motor without being destructive.

- correct, what I meant is I don't want to end up with a swap that's high maintenance (aka s14) but more reliable.

I know of a turbo m50tu turbo 325iS that has been very soild. Tuning is the key. I'll let others chime in on specific items of concern besides the obvious areas.

- if I go with m50 swap it will stay NA, as the whole point is for it to also pass smog, if I throw a turbo on it I might as well do it to the m10 if you know what I mean.

[Rob]

also keep in mind classing if you want to be competitive in autocross. If you dont really care about standings and just want to have fun, do whatever motor you want. I'd personally rather have a 2.5 m50 than just about anything else, good combination of power, reliability, clean running. Some motors may have "too much" power (subjective thing), but I'd rather have the car skewed in favor of handling that power.

[jlevie]

also keep in mind classing if you want to be competitive in autocross. If you dont really care about standings and just want to have fun, do whatever motor you want. I'd personally rather have a 2.5 m50 than just about anything else, good combination of power, reliability, clean running.

Given a choice between a turbo M10 and an M50/52 I'd take an M52B25TU for the broader torque curve that dual Vanos provides.

[matt]

Given a choice between a turbo M10 and an M50/52 I'd take an M52B25TU for the broader torque curve that dual Vanos provides.

I don't think anyone's ever put a dual vanos motor into an e30.

I think that if your goals are modest (200hp) a turbo M10 can be almost as responsive as an NA motor at the same power.

Then again, a mostly stock NA M50 can make 200 at the wheels too.

[Jean]

My goals I believe fall under "modest" category , in a sense that I am not looking for a 300hp+ monster with no traction. I've done enough suspension and maintenance work to get me started so now I would like to research and plan power upgrade(s). If the car is capable of running mid 13s I will be happy. My previous car ran a very low 14 and was quick enough in auto and at hpde plus it was much heavier than the e30.

The fact that even with low boost on the m10 I wouldn't be able to make it smog legal is turning me away from it and that's why I am leaning more towards an NA setup.

As far as classification goes, I am doing this just for fun and will probably end up in the SM (i believe they allow engine swaps iirc) category.

[euroshark]

M50 / S50, I think it will give you the best drivability, especially for the track. A turbo M10 would just be... impractical.

[iNetMANN]

Jean,

I AutoX an '85 318i and still have an M10 without boost. I race in SM (Street Modified) class and last year (2006) I finished 2nd in my class. Here's a video from last season of the car, give it a watch than you decide if boost is needed. This was a very big open course so I was beat by the big HP cars but really held my own.

http://www.stickypod.com/videos/data/556/ASNW_Event7_-_2006_Short_with_music_-_large.wmv

***Caution*** this is a 37Mb file
Watch the GTech Pro on the dash, Single Red light=6000 RPM & Flashing Red lights = 7000+RPM

Remember, whats even better than big HP? Less weight! I'm 2269Lbs lite!
Another thing in AutoX is the PAX multiplier that can give you big advantages. My other 318i is a bone stock version that I've AutoX'd on occasion and it's classed in HS (H stock), best PAX of all classes. I've won my class everytime I've brought that car.

In my opinion, leave the car alone, improve the driver, than improve the car!

RODD

EDIT* Also, an autoX car and a 13sec 1/4 mile car have nothing in common except they're both timed events.