M42club.com - Home of the BMW E30/E36 318i/iS
DISCUSSION => General Topics => Topic started by: Frankie on May 30, 2007, 12:31:38 PM
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Well, I have a stock (exl. cat-back dtm-exhaust) 318is and I wondering whether to buy a German made "Renn"chip which has rpm limiter raised to 7500rpm. 98 octane fuel should be used.
What is your opinion, is that rpm figure too much?
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Well, I have a stock (exl. cat-back dtm-exhaust) 318is and I wondering whether to buy a German made "Renn"chip which has rpm limiter raised to 7500rpm. 98 octane fuel should be used.
What is your opinion, is that rpm figure too much?
stock cams at least should be adjusted for these rpm
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stock cams at least should be adjusted for these rpm
how would you adjust the stock cams? do you mean cam timing on the sprockets?
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Well, that rpm figure seems bit high, so I decided to buy ZoneChip (http://www.evo-s.co.uk/shop/index.php?cPath=6_2279) instead. Actually, I don't know how much the zonechip will raise the rpm limiter?
Anyway, I'm gonna dyno what ever chip I'm going to buy in the end.
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how would you adjust the stock cams? do you mean cam timing on the sprockets?
yes
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I have been under the impression that the crankshaft vibration damper will disentigrate above 7200 rpm, and the BMW manual that came with the car said that the "engine is designed to rev up to 7200 RPM." With a stock engine, however, I'm not sure how much of a difference the extra 300-400 RPM would make, so I would play it safe.
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Well, I have a stock (exl. cat-back dtm-exhaust) 318is and I wondering whether to buy a German made "Renn"chip which has rpm limiter raised to 7500rpm. 98 octane fuel should be used.
What is your opinion, is that rpm figure too much?
Frankie,
it's not safe to rev that motor so high. My hottest chip for the E30 M42 has a 7150 rev limiter. I doubt you will find a better chip anywhere. (unless they are cloning mine)
If anyone here is interested in one, I can run a group buy.
MarkD
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Frankie,
it's not safe to rev that motor so high. My hottest chip for the E30 M42 has a 7150 rev limiter. I doubt you will find a better chip anywhere. (unless they are cloning mine)
If anyone here is interested in one, I can run a group buy.
MarkD
a group buy would be nice.
i sold your chip to someone here on the forum (alpine003) and regret it.
i was hoping that miller performance would actually come out with the MAF conversion
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a group buy would be nice.
i sold your chip to someone here on the forum (alpine003) and regret it.
i was hoping that miller performance would actually come out with the MAF conversion
I posted this in another thread today, I'll post it in it's own thread later today:
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http://www.m42club.com/forums/showthread.php?t=2882
How many of you would like one of my e30 318is chips? I will be happy to run some sort of group buy.
How about:
5 to 9 orders = 10% off
10 to 19 orders: 15% off
more than 20 orders: 22% off the posted price!
It would run like this: Order your chip from the site, quote this sale code: M42CLUB-GB
and soon after the sale ends, I'll tally up how many sales came in and send the discounts. I can also post every week how many orders arrived with the sale code so you have an idea where the discount is heading.
This group buy will run from now till July 5.
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I posted this in another thread today, I'll post it in it's own thread later today:
*******************************************************
http://www.m42club.com/forums/showthread.php?t=2882
How many of you would like one of my e30 318is chips? I will be happy to run some sort of group buy.
How about:
5 to 9 orders = 10% off
10 to 19 orders: 15% off
more than 20 orders: 22% off the posted price!
It would run like this: Order your chip from the site, quote this sale code: M42CLUB-GB
and soon after the sale ends, I'll tally up how many sales came in and send the discounts. I can also post every week how many orders arrived with the sale code so you have an idea where the discount is heading.
This group buy will run from now till July 5.
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Oh fawk, perfect timing with the student loans!! Guess the dinan chip is on the way out the door!! Mark D you rock bro :)
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Ive got a MarkD chip in my 318is.
My car came with the Bav Auto one, but I switched to one of Marks chips. Revving past the end of the tach is great. His chip really livens up the motor.
Hunter
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Ohhh its so tempting. Ill probly wait for a bit and see how many people join though...
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Damn, I don't have the money for that. That sucks...
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Well, what is the intial price for the chip?
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Mark, I would start something up in the Group Buy section then.
Lets see how much interest we can generate :)
I posted this in another thread today, I'll post it in it's own thread later today:
*******************************************************
http://www.m42club.com/forums/showthread.php?t=2882
How many of you would like one of my e30 318is chips? I will be happy to run some sort of group buy.
How about:
5 to 9 orders = 10% off
10 to 19 orders: 15% off
more than 20 orders: 22% off the posted price!
It would run like this: Order your chip from the site, quote this sale code: M42CLUB-GB
and soon after the sale ends, I'll tally up how many sales came in and send the discounts. I can also post every week how many orders arrived with the sale code so you have an idea where the discount is heading.
This group buy will run from now till July 5.
*******************************************************
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Mark, I would start something up in the Group Buy section then.
Lets see how much interest we can generate :)
Ok I'll do that now. I was busy tuning a secret project ;) yesterday so didn't get a chance to post it.
Mark
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I'm interested in buying one of the chip. I had one on order from another store I guess they were on back order so I cancelled it. My biggest challenge right now is finding me a Resonator to fix what I induce to my car, sounding like a "Ricer". So sign me up for the group buy.. What is the prize for none group buy?
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I want to see the differences between the MarkD chip and Dinan. Im very happy with the increases and drive ability of the Dinan, I would be happy to do a side by side comparison on the dyno if someone wants to send me a 91 octane MarkD.
To the OP, I rarely take the motor above 7000rpm cause theres really no need to.
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Hi there frankie, I think I know who you are :)
I have been eyeing those same chips too myself... The guy who makes them seems to know his stuff, also you can specify where you want the limiter to be placed when you order the chip.
I consider the vibration damber exploding at 7200 rpm to be a internet urban legend. Everybody knows about it but nobody knows anybody who has actually suffered a failure. I think real critical items are valve springs and bottom end.
If you want to play it safe assume that 6800 RPM (on E36) is highest you can rev safely. Then increase spring rate and/or make valve gear (lifters, valves, springs) lighter. Then you can actually calculate how high you can rev the engine without any fear (not taking account of bottom end).
There is also difference between E30 M42 and E36 M42. E30 used 7 mm thick valve stems, double springs and basically everything is 20-15% heavier than in E36. Maybe valve spring rate on E36 was smaller (to decrease friction losses), hence the pretty identical rev limit. But if you fit E30 springs to otherwise bog standard E36 head then you can increase the rev limiter safely to 7400-7500.
One quite easy way to lose valve train weight is lightweight VW hydro lifters, they are about 20 gr lighter than in E36 and 30 gr compared to E30.
E36 cylinder heads are very sought after in german ebay, they can go over 300€ when E30 head is maybe 100€ at best. That is simply due fact that E36 head has way better capability to rev.
There are running E30 M42's on ebay for few hundred €'s which is about three tanks full of gas. So if you overrev your engine, it's cheap to replace anyway :)
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Another thing...
It seems that peak power of M42 is reached at 7150 RPM according to the guy who sells his chips. There is not much reason to rev over that except on track. I learned that I could save perhaps 2 gearshifts per lap on local track if I could rev to 7000 or bit over it instead of 6800.
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Another thing...
It seems that peak power of M42 is reached at 7150 RPM according to the guy who sells his chips. There is not much reason to rev over that except on track. I learned that I could save perhaps 2 gearshifts per lap on local track if I could rev to 7000 or bit over it instead of 6800.
Maybe chipped is different, but most dyno's I've seen of our m42s the HP peak is at 6k?
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why would the E36 head have a better ability to rev? The double springs are better and the valve diameter is 1mm larger and the rest is fundamentally the same IIRC. Even then, why would BMW set the rev limit almost 1k RPM below what the engine's capability was?
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Well, I ran into trouble with the zonechip, they asked 15£ for shpping which is just outrageous. It's 5 £ at most by Royal Mail.
Anyway, here is the dynochart of my 318is. It's totally stock excluding the cat-back. As you can see from the graph the torque and peak horse power is little bit too near each other. Reason for this that the exhaust manifold flows too too much. The start of the manifold should be narrower and it should enlarge in 5 steps in order to be perfect.
Its 144hp and it would be great to see what would a "renn"chip do, would it actually worsen the result?? we will see in next episode.
Boyracer, see you on 5.7. Btw, what chip you are talking about - that Rennchip or Zonechip?
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This is the guy I'm speaking about, he sells some of his chips in german ebay:
http://freenet-homepage.de/pro-auto/startseite.htm
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why would the E36 head have a better ability to rev? The double springs are better and the valve diameter is 1mm larger and the rest is fundamentally the same IIRC. Even then, why would BMW set the rev limit almost 1k RPM below what the engine's capability was?
Double springs resist spring surge better and they are indeed stiffer on E30. But they have to be to counter the greater mass of valves, springs, lifter etc.
Valve diameter is exactly the same on E30 and E36, only the stem diameter changes. And smaller is better because it is smaller airflow obstruction on port and it is lighter.
Stock E30 7 mm stem valve, spring, lifter, keeper and retainer has mass of 219 grams.
Metric Mechanic setup with 6 mm parts (basically E36 M42) has mass of 166 grams. That is 25% lighter! :cool:
That is why BMW used softer springs on E36, it does not need to be as stiff as in E30 to rev to same limiter. But because the springs are softer you have less power loss to them even if you cannot rev any highger.
Ok, lets say e30 springs are 25% stiffer (Dbilas site lists E30 springs 115 kp against E36 86 kp). When you fit them to bone stock E36 M42 you can rev it safely up to 7850. Not sure if they are straight swap, can anyone confirm, but you get the idea.
To get E30 M42 to rev that high you would need need again 25% stiffer springs which starts to be in race engine category -> expensive and rare. And your power loss and camshaft wear would go up. And you would still have thick valve stems obstructing the air flow in intake ports. OR, you could swap the valves and lifters etc to lighter ones from E36 :)
So E36 requires less parts to be changed to rev high. Lighter valvetrain is almost always better. It is better to lighten the valvetrain than to make springs stiffer.
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huh, good to know. Thanks for the great explanation. Any idea if e36 valves, lifters, keepers, retainers, etc are direct fit into the e30 M42?
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I *guess* complete E30 and E36 heads are interhangeable... So it could be easiest to find complete E36 M42 head and fit it to E30 engine?
But to complicate things, the very early E36 M42's were equipped with 7 mm valves too. I think they were made until summer 1992. That early head is not improvement over E30 head I think. Head I bought is from 318ti which went to production sometime in 1994 so it should be 6 mm head, we will know for sure next week :eek:
Again, I think you can put 6 mm valves, lifter etc to 7 mm head BUT you have to change the valve guides. This requires trip to machining shop. Not a big problem if you are planning to get head ported and valve seats reground etc anyway.
This is information I have studied from BMW parts catalog, books and net during the last year. I have not yet actually worked with any M42 heads yet (I will start next week) so I might have missed some details. Anyone who thinks I'm talking bollocks please correct me, then we all are that bit wiser :)
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Well, here you can "see" the e36 318is revving ~8000rpm. It's turbocharged.
http://www.youtube.com/watch?v=ElaB8jK_9pw
I think that dude is active in this forum. I don't know what mods he has done, but nice nevertheless
Edit: it does not seem to rev even to 8000rpm?
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looks like 7500-7800 RPM. either way, its impressive. wonder what kind of numbers he's putting down.
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Well, here is the thread regarding his car http://www.m42club.com/forums/showthread.php?t=2404