318is m42 bhp?

[tomson]

149 and 150bhp respectively from cars which left the factory 18 years ago with 136bhp.

How anyone can take figures from that rolling road seriously is beyond me.

Exactly why I didn't bother putting mine on there.....

[GrindCulture]

149 and 150bhp respectively from cars which left the factory 18 years ago with 136bhp.

How anyone can take figures from that rolling road seriously is beyond me.

Exactly why I didn't bother putting mine on there.....

Same here....honest

[ShepsEvo3]

There was a theory being thrown around about the 318is having alot of mass inertia from the flywheel and thus making dyno's show a higher output than it actually is. It can be cancelled out by measuring power at 500 RPM increments with no acceleration going on but then things like heat soak could start comming into play and show lower figures anyway.

If I had time or I would do a direct comparrison between standard and M20 flywheels with no other change and see if there really is an inertia thing going on.

Obviously on an engine dyno you wouldn't have this as the dyno is bolted straight onto the crank.

I agree that different makes of dynos give different results, even wheel power cannot be compared across dyno's. For instance, I have found our Dastek generally shows a higher output at the wheels than say a Dyno Dynamics machine, but after corrections within the software, the flywheel figures are very similar/comparable between machines when the correct shootout modes are used in the DD machine.

With readings on our dyno Jon's MI16 for instance was 155bhp @ 6500 and 134ftlbs @ 3500 out the factory (with catalyst). His car made slightly less peak torque but made more power. This can be due to a different induction kit which slows air speed down at lower RPM but is less restrictive than the standard air filter system and coupled with no catalyst that it breaths better at the top end, where it hangs onto its torque for longer and hence still making power at 7000 rpm. So our figures I would say are very believable. How about this one... Latest R32 Golf 4motion with 1k miles on the clock made 251bhp and 236ftlbs on 2 seperate runs on our dyno a few months back. Which I am led to believe is bang on the money.

[pugboy]

Jon I assume your Mi16 is a 1.9? Mine was from an F plate so obviously non cat. They are supposed to be 160bhp, but if you have a modified exhaust manifold that could drop the power down to 155. My engine was a low miler and I had it fully rebuilt before it went in the car so it was very healthy.
The BX box will be the same as the Mi16 I imagine (short 1/2 and longer 3/4/5). The 1.9 box is all wrong - dont even consider that! The 1.6 box is the way forward unless your car is going the Nurburgring several times a year. Your car is stripped out which might help a bit, but honestly they feel so much quicker on the 1.6 box. Put it this way the 1.6 will keep up with the 1.9 most of the time and aside from the 1.9 never making its power its down to its longer gearing.

Oops we have gone off topic here haven't we. I doubt I'll ever feel the love for the iS that I did the Mi16. Still you never know if the iS proves to be uber reliable then it might win my heart (I am turning 30 soon!).

[Jon_Bmw]

Yeah, its a D6C mi16 out of a bx, supposedly the best one which did produce 160bhp, it was the highest compression one as standard(10.4) which is a bonus and hence probably made 160 rather than 155. 2 row ECU, no knock sensor or Lambda sensor. The exhaust manifold is un-changed, but it has a custom downpipe which annoyingly doesn't have the split in it. One of the reasons it was no doubt slighly down on torque at Sheps' rollers.
But probably another reason why it then revs very well up to the rev limit. It made maximum power at the limiter(7100) which I expect was due partly to the exhaust. I posted up the graph somewhere on here.

Next step, change the inlet cam and raise the rev limit to 7400/7500 and see what difference it makes. I expect it to go from 163bhp to around 175/180. After that it starts to get expensive, but the idea with this car was it to weigh about 800kilos..done and have 200bhp...not done.

Interesting about the box's, I definatly need to go in one that has the 1.6 box in it to make up my mind. I fear that although it may feel faster it actually won't be due to the time spent changing gear(lets be honest a 205 shift is hardly smooth and quick, despite the short shift on it! )

Currently 1st does about 35mph+
2nd= 65mph+
3rd= 90mph
4th =115mph
5th = untried

Doing 115bhp in a lowered 205 feels about 250mph I am sure on bumpy roads.

I really like my iS as a daily, I love the driving position, find it easy round town with power steering and a light clutch, it also just needed a bit more power from the factory. Can't have it all though

[pugboy]

My Mi16 would rev higher than 7100 (well at least indicated higher anyway). It was using the standard manifold that had a bit chopped out to reangle it. I think it went to about 7300rpm.
The 1.6 box is awsome and it felt so much quicker than the Mi16 box with its longer gearing. Once I put the Mi16 box on it was no quicker than a Clio sport etc. Not 100% about the top speed, but it would easily hit the limiter in 5th (the needle would shake so much it was hard to tell!). I'd guess about 120mph.