M42club.com - Home of the BMW E30/E36 318i/iS
DISCUSSION => Engine + Driveline => Topic started by: PerTore on January 16, 2012, 02:44:10 PM
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Hi.
I have a 90" 318is rally car that I could use more power in. I have dismatled the engine for a check, and it looked good inside. I'm going to fit new pistonrings, but the bearings looks brand new, so they will do for now. I'm thinking about a new set of cams, any good suggertions?
I'm also hoping to use the standard FI, maybe fit bigger injectors, and turn up the fuel pressure. Will this work?
Any other ideas on how to get more power, will be appreciated.
No turbo or supercharger are allowed.
(sorry for my "Petter Solberg-english". I had, like him, my mind on rally when I was in school);)
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I can do a custom or standard chip for your setup
Contact me at midnight-tuning@rogers.com
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A chip would really wake the car up, I'd bet. Likely that's the best bang-for-your-krone. Single mass M40 clutch and a higher ratio diff (like a 4.1 or so) are a big help as well. Dropping weight is another easy mod...eliminate all the insulation, the spare tire, CF hood, patch up the sunroof, racing buckets, etc.
Might want to double check the bearing clearances & fit a full-radius thrust bearing. We only got a half-shell (an M50 has the right one IIRC). There's a thread on here somewhere about it. While you have it apart I'd be tempted to measure the oil pump, replace a lot of gaskets, change the cam gears, idler gear, worn timing components and the water pump.
Given that you can't use forced induction, I'd spend some time porting that head, removing the throttle heater and the mess under the intake if possible & fitting a cold-air intake. Degree the cams, insulate the intake manifold, wrap the exhaust, install a wideband O2 sensor, and use the thinnest fully-synthetic oil you can get away with in the entire powertrain.
If you're really looking for more power, might be worth it to find an M47 crank for longer stroke. It looks stock, you'd need a really good mechanic to note the difference. IIRC S52 pistons are the best combo with these...
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Stroking is not allowed, and it will be checked from time to time at scrutening. The car already have the 4.1 diff ratio. And I will of coure change all gaskets while I have it apart. CF hood is not allowed, and the weight is already on its minimum.
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A chip would really wake the car up, I'd bet. Likely that's the best bang-for-your-krone. Single mass M40 clutch and a higher ratio diff (like a 4.1 or so) are a big help as well. Dropping weight is another easy mod...eliminate all the insulation, the spare tire, CF hood, patch up the sunroof, racing buckets, etc.
Might want to double check the bearing clearances & fit a full-radius thrust bearing. We only got a half-shell (an M50 has the right one IIRC). There's a thread on here somewhere about it. While you have it apart I'd be tempted to measure the oil pump, replace a lot of gaskets, change the cam gears, idler gear, worn timing components and the water pump.
Given that you can't use forced induction, I'd spend some time porting that head, removing the throttle heater and the mess under the intake if possible & fitting a cold-air intake. Degree the cams, insulate the intake manifold, wrap the exhaust, install a wideband O2 sensor, and use the thinnest fully-synthetic oil you can get away with in the entire powertrain.
If you're really looking for more power, might be worth it to find an M47 crank for longer stroke. It looks stock, you'd need a really good mechanic to note the difference. IIRC S52 pistons are the best combo with these...
What Dave said....btw I have a nice 4.27lsd available, pm me if ya like.
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Thanks everyone. I've just ordered A set of 269dg Cat Cams and a matching chip from Motor Nord in Sweden, and a new set of piston rings and bearings is fitted, along with cylinder honing I think this will do for now. Anyone with a qualyfied guess on what power I'll be looking at?? I'll take it to the dyno afterwards, mostly to see if the mix i right, but I'm also curious on the power, of course...
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There's no need for cams. Your stock cam gears are adjustable. Search the forums. I believe there are a couple threads that mention the adjustments to be use. Combine that with the Mark-D chip, and you'll have a considerable amount of gain.
Have you done the electric rad fan conversion? Have you taken out the A/C hardware? Did you remove power steering?
Since this is mainly for track, I have to ask: have you installed adjustable shock mounts in the front/rear? A properly adjusted suspension can be worth considerable time on your lap, unless it's a track meant for cars with power, i.e. long straights.
Back to the diff. Are you running the stock bushing, poly, or a solid plastic one? If stock, have you checked it lately? Might make a diff in the longevity of your next diff. Also, is your guibo still good?
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Yes, electric fan is fittet, no power steering, no A/C. Rally springs and shocks is fitter, I've done a few rallies with it, and it handles great. All bushings are stock, and they are in great shape. Rallies in Norway mainly runs on "bad" roads, with potholes, bumps and jumps, on gravel or snow/ice surfaces. I belive that rubber is the best materials for bushings etc., plastic will be too hard, and cracks in mounts in chassis often appear on the cars that runs with plastic bushings.
What is a guibo??
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guibo-generally accepted term for the rubber do-nut BMW uses on the driveshaft instead of a steel u-joint:)
Geoff
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Ok. Thats what I thougth.
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There's no need for cams. Your stock cam gears are adjustable. Search the forums. I believe there are a couple threads that mention the adjustments to be use. Combine that with the Mark-D chip, and you'll have a considerable amount of gain.
Have you done the electric rad fan conversion? Have you taken out the A/C hardware? Did you remove power steering?
Since this is mainly for track, I have to ask: have you installed adjustable shock mounts in the front/rear? A properly adjusted suspension can be worth considerable time on your lap, unless it's a track meant for cars with power, i.e. long straights.
Back to the diff. Are you running the stock bushing, poly, or a solid plastic one? If stock, have you checked it lately? Might make a diff in the longevity of your next diff. Also, is your guibo still good?
The cam adjustment will only be a good option if the rules do not allow anything but factory camshafts. The gain from advancing the intake came will be a slight bump in mid-range torque (which will be good for rally). Even then, its not the best option.
My recommendation would be to look at catcams.be as they have many grinds and can even do custom grinds.
If you get some reasonable cams you will need a custom tune...the markD will not be enough for compensation to get full benefit.
Which part of Norway are you from? I have spent some time there on holiday.
Tusen takk
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Thats exactly what my setup will be. 269dg cat cams, and a matching chip from motor nord in sweden.
I'm from the south/east of norway, 1 hour drive west from Oslo
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That sounds like a great setup! Looking forward to seeing a dyno chart!
I took the train from Bergen to Oslo. I also went from Oslo to Lillihammer and all around. Fun trip, wish I was back there now!
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Thats a great train ride!
I hope to get the parts and have it assembled during next week, so a dyno run is in the nearby future ;) Any guess what power I'll be looking at??
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Hard to say. It depends a lot on the tune!
One other thing to consider is an exhaust header. The factory tubular manifold is decent, but if you are racing you want all you can get. I have seen people get much better results with a proper set of long tube headers. This will also help give you some lower end grunt, which you want in rally.
Supersprint makes some headers and there are some cheapo copies on ebay. Personally I would pay for the real deal, especially if you can find a set used!
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So, now the engine is in the car, started, and braked in. I took it for a test run now, and I'm very satisfied with the result. It idles like a tractor, though, but I'll look into that later. It idled bad before I took it apart, so that doesn't worry me much. I don't think I've lost too much in the lower register, and passing 5000 rpm its hysterical! Now the need for a new gearbox is starting to get clear! I had to change the original gearbox, and I got what i thought was an identical box, but it's obviously not. Still it is a Getrag 240, but the range is definitive not meant for rallying. Any good ideas?
I hope to get a dyno run this week. Exited! It feels like 150+hp, but you'll never know...
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The manual from the e36 has much different gearing. Its a lot steeper as 5th is a 1:1 gear. Is your car e30 or e36?
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I have a 90" E30. The 4th is 1:1' and the 5th I think is 1:1.4. What I need is a gearbox with a high ratio 1st and 1:1 on 5th.
Dyno is due on Monday :)
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PerTore...if your 4th is 1:1 then your 5th, which is then considered an overdrive, would have to be more like 1:.81
If it was 1:1.4 then that might be a 3rd gear in a close ratio set up.
Cheers,
~Ralph
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Yes, you're completly right, of course! :)
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Just in case you haven't seen the website, although you probably already have
http://metricmechanic.com/
they have great ideas on how to get more power out of an m42 if you want to spend $$
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Ok, if I've got it right my 240 tranny has this ratio
1st- 3,764
2nd- 2,00
3rd- 1,33
4th- 1,00
5th- 0,81
And this sound like a "not too bad for rallying"-ratio, right? Does there exsist 240's with different ratios? Or is it bulletproof that this is my ratio when I've got a 240?
It says on the housing, right side bellhouse 240.0.0370 90' and rear housing 240.0.0366 91
And 225 and 1.4.
I've also got a 220 from an E36 lying around, and I think this is the same as the 250. This is considered to be a "close ratio" tranny, but I just can't understand why, considering the ratio
1st-4.23
2nd- 2.52
3rd-1.66
4th-1.22
5th-1.00
With my 4.10 diff ratio the insanly low 1st will be completly useless with the 220, and 95% of rallydriving will be in 2nd, 3rd and 4th. The difference between 2nd to 3rd will be 0.86 (0.67 with the 240) from 3rd to 4th 0.44 (0.33 with the 240) short story, the ratio"gaps" is considerably bigger with the 220, than the 240
Am I completly lost in my theories (or math) here? Please enlighten me...
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Ok, mods! I wrote a long message with high level ratio math and reasearch. It had to be "passed by a moderator" to be posted on the forum. The last time I got this message, my two messages "dissappeared" Hope it won't this time...
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I got it. I know, the spam filters are annoying. Please accept my apologies.
If my math is correct, you had to wait a grand total of 50 minutes for it to be fixed...how's that for service?
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The Getrag 220 and 250 have the same, or at least similar, ratios, but the 250 will be the correct fit for the M42. The 220 is a fair bit longer, iirc. I'm not sure if the output flanges are the same or not.
Just to quell any misinformation right here, adjusting cam gears is in no way a substitute for aftermarket cams. What the M42 really needs is a little more lift and duration (those catcams should work great, and are a step above the usual S50 profile a lot of M42 cams use). Note that you can also get more reliable high revs out of the engine by fitting solid lifters ($$$) and you can bump up the high end by fitting larger valves. Later M42's also have narrower valve stems (6mm vs 7mm diameter) that allow for slightly better flow.
Lighter flywheel will do wonders for the responsiveness of the engine, and acceleration in first and second gears.
When you have the chip made, for maximum performance you will want to have it dyno'd on your car, with your setup. Changes to the intake and exhaust along with minute production and wear differences between engines means that most chips are conservative for most cars.
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Exellent! No problem. I was afraid I had to write it all over again. (I was very tired last night, so please forvgive my harshness ;)
Edit: was ment for DesktopDave
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The dyno run was good today. I've got 152hp at 6000 rpm and 187,5Nm torque at 5400 rpm, and thats about what I hoped for. Great mix all over, and good driveability from 4500 to 6500 so overall very positive. I'm really looking forward to race it now!
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How much did the cams and chip set you back?
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There's a cheap, or should I say less expensive ;) way to raise the CR a bit to around 11:1. Try to find a set of used M52B28 pistons (328,528 etc..) and shave about 0.2-0.3 mm of the piston top to get the same compression height as the standard M42. I don't remeber the exact dimension since it was about 7 years ago I did this unfortunately. You also need to mill new valve pockets. That piston is also lighter with a different design on the piston skirt.
A bit late information but now you have some time to source the parts before next overhaul. :)
Lycka till i rallyskogen ;)
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The dyno run was good today. I've got 152hp at 6000 rpm and 187,5Nm torque at 5400 rpm, and thats about what I hoped for. Great mix all over, and good driveability from 4500 to 6500 so overall very positive. I'm really looking forward to race it now!
Any chance you can post a graph?
Nice numbers!