How fast can an E89 go? Part Deux!

[Argyll Andy]

... on a side note id LOVE to see one up against a like for like z4m ( stock ) on a variety of different roads etc. would be so interesting .....

Only small insight I can give you to that from personal experience is on a forum run I had the M40 and Paul Harvard had his stock M. We had a few chats over the weekend and the summary iirc seemed to be he was very impressed with how quickly the M40 accelerated, particularly out of corners and when overtaking. He mentioned that a couple of times the M40 had overtaken in places he didn’t think he’d have managed and also when he’d overtaken and I came with him if the positions had been reversed he possibly wouldn’t have followed me if I’d have gone first. I’m putting that down solely to how quickly the M40 gets up and moves due to the turbos/torque. Can’t comment on the M but the brakes on the M40 are also fantastic and can help you greatly when making progress. The other thing Paul commented on was how flat and compliant the M40 was in the corners and more uneven surfaces compared to his. It wasn’t just him who mentioned this, at least 3 others on the same run said the same thing when they’d been travelling behind me. Had similar comments from the group on the NC500 too.

Before this run I had never experienced a Z4 M before in any capacity and after reading all the praise and love for them on here I wasn’t sure how the M40 would cope in that company. My personal summing up is we both travelled in front of and behind each other at various stages over the weekend and tbh I don’t feel either of us was holding the other up ( Paul might say different :lol What I would say is based on some of the above, and if we were travelling the same type of single carriageway roads, when I was in front I could possibly nip in and out of traffic more easily and over a distance might gradually make more progress. In stock form the M40 also seems to handle better, newer technology so can only be expected. On a free open road, apples for apples (stock cars and similar ability drivers), reasonable conditions and free reign, IMO whoever was in front would very likely stay there, on a straight drag race I think there’s posts on here quoting figures, YouTube videos etc that state the M40 is quicker but that’s not how 99% of us use our cars :driving:

The differences I’m highlighting are mainly down to the car, power, advances in technology etc and not any driving god status claims, just all imho

.

 

[raven]

The one G29 that has me in complete awe is [ref]raven[/ref], one. The colour is stunning, by far the nicest one I’ve seen yet and the thing that seems to slip under the radar is that it’s running 440bhp, (so 40 more than the one you drove) and also a very healthy chunk more torque) As far as I’m concerned that’s the benchmark in my eyes :wub: :driving:

Thanks, if you don't live in Europe I'm sure you can get a G29 Z4 close to double of what I have now on the block that's in there and a big budget

How its set up now is perfect to still daily drive it. Only a little hard to stay under the speed limit at times
I think much higher might become a bit annoying for a daily driver.
But that's what I said too back when it was at 400

 

[B21]

The one G29 that has me in complete awe is [ref]raven[/ref], one. The colour is stunning, by far the nicest one I’ve seen yet and the thing that seems to slip under the radar is that it’s running 440bhp, (so 40 more than the one you drove) and also a very healthy chunk more torque) As far as I’m concerned that’s the benchmark in my eyes :wub: :driving:

Thanks, if you don't live in Europe I'm sure you can get a G29 Z4 close to double of what I have now on the block that's in there and a big budget

How its set up now is perfect to still daily drive it. Only a little hard to stay under the speed limit at times
I think much higher might become a bit annoying for a daily driver.
But that's what I said too back when it was at 400

Raven, do you have a dyno print out of your latest iterations pls?

 

[raven]

The one G29 that has me in complete awe is [ref]raven[/ref], one. The colour is stunning, by far the nicest one I’ve seen yet and the thing that seems to slip under the radar is that it’s running 440bhp, (so 40 more than the one you drove) and also a very healthy chunk more torque) As far as I’m concerned that’s the benchmark in my eyes :wub: :driving:

Thanks, if you don't live in Europe I'm sure you can get a G29 Z4 close to double of what I have now on the block that's in there and a big budget

How its set up now is perfect to still daily drive it. Only a little hard to stay under the speed limit at times
I think much higher might become a bit annoying for a daily driver.
But that's what I said too back when it was at 400

Raven, do you have a dyno print out of your latest iterations pls?

Yes, I think I have one printout for each change I did, I'll look them up and send them together with what changes I made this weekend.

I think if they spent more time tuning for the current setup 500hp should definitely be possible, but it was a bit of a rush job, did wheel swap, custom exhaust, stage 2 tune and delivery to the paint-shop in only 4 hours or something

 

[B21]

Thanks, if you don't live in Europe I'm sure you can get a G29 Z4 close to double of what I have now on the block that's in there and a big budget

How its set up now is perfect to still daily drive it. Only a little hard to stay under the speed limit at times
I think much higher might become a bit annoying for a daily driver.
But that's what I said too back when it was at 400

Raven, do you have a dyno print out of your latest iterations pls?

Yes, I think I have one printout for each change I did, I'll look them up and send them together with what changes I made this weekend.

I think if they spent more time tuning for the current setup 500hp should definitely be possible, but it was a bit of a rush job, did wheel swap, custom exhaust, stage 2 tune and delivery to the paint-shop in only 4 hours or something

Look forward to that..my experience was that both settling in and re-visit gave some small but positive benefits..

I would think you are close to the limit without HPFP changes..IMHO...FWIW

 

[sars]

This is getting interesting! that is the differences between the Z4M and the M40i, so for all you eggheads out there I've been busy again. You will appreciate that Acceleration = Force/mass, when related to your car, mass is constant and the force varies with RPM, gearing & final drive ratios and then the diameter of the wheel. To compare the two power trains, the Z4M against the Z4 M40i I've plotted in the first graph Torque (Nm) vs RPM so you can see the difference, the 3.2L S54 has a wonderful torque curve for a naturally aspirated engine and even at 8000 rpm, torque does not fall off a cliff. In comparison the B58 produces torque like a switch with the artificially restricted peak of 500 Nm from 1600 to 4600 rpm.
From there, I calculated the force generated for each gear against speed in mph (up to 100 mph)

The second and third graphs give a great indication of how these cars drive by detailing the force generated at a particular speed, given the constant mass, this in reality depicts the change in acceleration as rpm changes in each gear.
The Z4M change in acceleration is pronounced, the higher the rpm the more force and the faster you accelerate, it makes you want to rev that engine to the highs, Whilst the Z4 M40i with that constant force between 1600 and 4600 gives that smooth and endless push, which never seems to stop.

 

[tiglon]

This is getting interesting!

I was going to make a joke at this point, but I read through the rest and it was fairly interesting

Good illustration of the classic NA vs modern turbo characteristics.

Personally, for a daily driver I'd want the turbo, and for a purely weekend toy I'd want the NA. Either way though, I'm sure both a Z4M and M40i would be bloody brilliant.

 

[raven]

Look forward to that..my experience was that both settling in and re-visit gave some small but positive benefits..

I would think you are close to the limit without HPFP changes..IMHO...FWIW

I cant find the one from the first tune, but it is basically the same as the thin line in the first graph.
That was a tune + modification of the end muffler.

The thick line is same tune but with the eventuri intake.



Then the second graph is the stage 2 tune
With the new 200 cell downpipe and the front muffler from the US model and opf delete

 

[B21]

Look forward to that..my experience was that both settling in and re-visit gave some small but positive benefits..

I would think you are close to the limit without HPFP changes..IMHO...FWIW

I cant find the one from the first tune, but it is basically the same as the thin line in the first graph.
That was a tune + modification of the end muffler.

The thick line is same tune but with the eventuri intake.

1.jpg

Then the second graph is the stage 2 tune
With the new 200 cell downpipe and the front muffler from the US model and opf delete

2.jpg

Thnx, much appreciated..all good stuff…

I assume you don’t have a baseline run?

 

[raven]

Thnx, much appreciated..all good stuff…

I assume you don’t have a baseline run?

no I don't have one, I think they only hooked it up to the dyno after my first exhaust mod , if I remember correctly it was at 350hp and about 550nm before the tune

 

[B21]

Thnx, much appreciated..all good stuff…

I assume you don’t have a baseline run?

no I don't have one, I think they only hooked it up to the dyno after my first exhaust mod , if I remember correctly it was at 350hp and about 550nm before the tune

..pity but often the case…the rest is good food for thought!