M3 with S62 M5 engine

[Jake]

The suspension for the E60 was designed to function
correctly at a given wheel base and overall wheel track
with static and loaded weight tranfer from a near on 2 ton car...

Its easy to throw it out there but its hardly definative Danny. Its like saying the basic E30 suspension design cannot cope after you strip an E30 M3 down to 2000lbs, boost the power to 420hp, add 30lbs to the nose, make the shell stiffer with a super expensive exotic steel cage, triple the stopping power, then add slicks and aerodynamics. On the contrary, in fact you can by specing appropriate damping & spring rates and adjusting camber, caster and toe as needed. Your conclusion ignores the details and over generalizes the work that went into the "Fraken One" with obvious intent to down play the project.

Jake

[Gorilla]

Hi,

Jake, not at all.

Your not comapring like for like.

To make the E60 suspension fit an E30
the overall track and wheel base has to be reduced.

This will alter COG in relation to the front
and rear point load pickups, and more importantly on
the front it will impact on the way the front
loads and of course turns in.

On a E30 with coilover changes, ARB etc and
even lowering the car the dynamic inputs are
still relative to the original chassis pickups
in that the load and weight transfer, no matter
what the power is, is still being transmitted
directly into the chassis at the original load points.

As an example S54 is about 60 od KG/s heavier than
the S14, but even fitting in the normal S54 conversion
engine position, the front to rear weight ratio does
not alter dramatically, so by compensating the extra
weight with suspension upgrades, the E30 when done
will still more or less handle along the same lines as
before.

Not so on the Franken car.

You can not just alter the distance from N/S to O/S
and fit it, alter all the load points into the
chassis and expect it to work as before.

The overall track on the E60 M5 is not the same
as an E30 M3.

The E60 suspension was designed to work at a give
O/A Track width, hence why increasing front
O/A Track will improve handling as it does on
most front engined rear wheel drive cars, but making
the front narrower will make it worse.

Looking at the build photos, Franken car,
the suspension now has a shorter
O/A Track front and rear to fit the E30 Shell..

Thats why when you lower a std car thinking
it will handle better as you have lowered the
COG its not always the case, and in many instances
lower results in a worse handling car, not better.

Lower may be perceived as better for the purpose
of COG but your suspension has to be able to
work.

The part which really raises the question is that
the E60 M5 its not a sublime handling car to start
with, so by altering the dynamics of the suspension
by reducing O/A Track, especially at the front ,is
ceratinly not going to improve, if anything it will
make it far worse.

Regards,

The Gorilla.

[UweM3]

Is the V8 M3 really handling "THAT" bad? Find it hard to belive to be honest.
It all depends on who is judging IMHO. One's "bad" maybe not as bad as someone others. If you of course expect race car handling it may well handle "bad".

I am sure even a "bad" handling Franken M3 will still be a blast to drive and still outperform much "better" handling cars.

[Gorilla]

Hi,

Uwe - I am Confused about the V8 M3 ?

I think the E92 M3 [ V8 M3] is quite a
well handling and balanced Car.

The Franken uses the V10 M5 as its base.

Regards,

The Gorilla.

[Jake]

It very well could be worse. But my point was that your argument lacts any real analysis. Regardless, I'm betting it's fine. Until you and I go drive it we'll never know for sure. So uh... looks like we're simply going to have to go find the owner and convince him to let us get behind the wheel for a spell eh?

Jake

[blaquea8]

So uh... looks like we're simply going to have to go find the owner and convince him to let us get behind the wheel for a spell eh?

Jake

+1
I think all forum members should be REQUIRED to drive it and "compare" it to their own cars... :gotcha:

[Apex Speed Tech]

As an example S54 is about 60 od KG/s heavier than
the S14, but even fitting in the normal S54 conversion
engine position, the front to rear weight ratio does
not alter dramatically, so by compensating the extra
weight with suspension upgrades, the E30 when done
will still more or less handle along the same lines as
before.

Not so on the Franken car.

I don't understand quite what you are saying here. Do you for some reason believe that the Franken car would not be an excellent handling car?

I think all forum members should be REQUIRED to drive it and "compare" it to their own cars...

People will criticize anything they can. Only 3 people have put significant time in the frankenbimmer - Mitch Piper, myself and the owner. Any other speculation on its performance is just that.

I've spent 15 years doing data acquisition and chassis engineering for pro-race teams; I have a fair idea of when things work and when they don't.

You know one the biggest thing doing this for a living has taught me? Bench racing doesn't tell you shit. Cars are about a variety of systems, interacting in complex ways. Yes, with the proper amount of simulation combined with properly verified models, you can very closely predict a vehicle's handling characteristics. But even then, no professional engineer is stupid enough to declare a car as "great handling" until a competent driver has evaluated it on the track.

But since its 8am on a Sunday and my 6 month old would rather have me here playing than off driving the canyons, I say its a fine time for speculating! Just keep your conclusions in perspective.

-Neel

[jibbajabba]

Hi,

Jake, not at all.

Your not comapring like for like.

To make the E60 suspension fit an E30
the overall track and wheel base has to be reduced.

This will alter COG in relation to the front
and rear point load pickups, and more importantly on
the front it will impact on the way the front
loads and of course turns in.

On a E30 with coilover changes, ARB etc and
even lowering the car the dynamic inputs are
still relative to the original chassis pickups
in that the load and weight transfer, no matter
what the power is, is still being transmitted
directly into the chassis at the original load points.

As an example S54 is about 60 od KG/s heavier than
the S14, but even fitting in the normal S54 conversion
engine position, the front to rear weight ratio does
not alter dramatically, so by compensating the extra
weight with suspension upgrades, the E30 when done
will still more or less handle along the same lines as
before.

Not so on the Franken car.

You can not just alter the distance from N/S to O/S
and fit it, alter all the load points into the
chassis and expect it to work as before.

The overall track on the E60 M5 is not the same
as an E30 M3.

The E60 suspension was designed to work at a give
O/A Track width, hence why increasing front
O/A Track will improve handling as it does on
most front engined rear wheel drive cars, but making
the front narrower will make it worse.

Looking at the build photos, Franken car,
the suspension now has a shorter
O/A Track front and rear to fit the E30 Shell..

Thats why when you lower a std car thinking
it will handle better as you have lowered the
COG its not always the case, and in many instances
lower results in a worse handling car, not better.

Lower may be perceived as better for the purpose
of COG but your suspension has to be able to
work.

The part which really raises the question is that
the E60 M5 its not a sublime handling car to start
with, so by altering the dynamics of the suspension
by reducing O/A Track, especially at the front ,is
ceratinly not going to improve, if anything it will
make it far worse.

Regards,

The Gorilla.

You keep mentioning the e60 suspension, which they didn't use. They used the e90 suspension, which is smaller in all diameters. Not as small as an e30, but def. smaller then an e60.

-Josh

[Gorilla]

Hi,

Quote-

'' People will criticize anything they can. Only 3 people have put significant time in the frankenbimmer - Mitch Piper, myself and the owner. Any other speculation on its performance is just that.

I've spent 15 years doing data acquisition and chassis engineering for pro-race teams; I have a fair idea of when things work and when they don't.

You know one the biggest thing doing this for a living has taught me? Bench racing doesn't tell you shit. Cars are about a variety of systems, interacting in complex ways. Yes, with the proper amount of simulation combined with properly verified models, you can very closely predict a vehicle's handling characteristics. But even then, no professional engineer is stupid enough to declare a car as "great handling" until a competent driver has evaluated it on the track.

But since its 8am on a Sunday and my 6 month old would rather have me here playing than off driving the canyons, I say its a fine time for speculating! Just keep your conclusions in perspective.

-Neel''

If you have 15 years of experince then you will know
only to well the issues associated with the points
I have already raised.

The E30 Chassis was never designed to run a
multi link rear set up, as the load points from the
multi link rear are transmitted into the chassis
shell at their 4 subframe points not the 2 on
the E30 rear subframe.

For sure you can pick these 4 load points up with a
bastardised Cage but that does not induce the
load into the chassis in the same way as the
E30, and therefore Traction, weight transfer,
etc will all be very different.

Furthermore as already stated the over all
Track width looks to have been decreased to
fit the E30 bodywork, which is a retrograde step
is as far that the E60/E90 Multi link rear was
designed to run at a given overall Track width.

Making this narrower alters the way it works
on a std E60/E90, what it does on a E30 who
knows, but even if it is 'bench racing' I say it
will not be better thats for sure.

Why ?

Simple go take any E60/E90 reduce the overall Track
width and then prove you have a better handling car.

Front engine rear wheel drive cars are always looking
for greater front track width not less.


As a tail note the E60 M5 has a better power to
weight ratio than say a E46 M3 CSL and certainly
a E36 M3 [Euro].

The E90 M3 also has a better power to weight ratio
that an E46 M3 and the E36 M3 [Euro]

Both the E60 M5 and the E90 M3 are slower around
the Nordschieife than the CSL or E36 M3.

You need a car to handle well, this is what I thought
the E30 M3 was all about ?.

Regards,

The Gorilla.

[strube]

With all of that said in the post above....what are you arguing?? That the E30 M3 doesn't handle as well as the E60/E90 with the swap? Or that the swapped car handles worse than a stock E30 M3? If you are saying worse, certainly it is going to handle differently, but outside of driving it, how would you really know that it is worse....I'm thinking that becomes a preference thing for the driver.

[Apex Speed Tech]

With all of that said in the post above....what are you arguing??

I'm kind of lost on that myself....

[Gorilla]

Hi,

Some things never cease to amaze.

Is there another language that is used
on the Forum for Technical points ?

Regards,

The Gorilla.

[bimmer]

This is all a big pissing contest :D

Put the Frankenmobile on a track and see what laptimes it does.

That is the ultimate test.

[Alpina]

This is all a big pissing contest :D

Put the Frankenmobile on a track and see what laptimes it does.

That is the ultimate test.

As a N/A E30 M3 ,,, yes

[UweM3]

Hi,

Some things never cease to amaze.

Is there another language that is used
on the Forum for Technical points ?

Regards,

The Gorilla.

Danny I do understand where you are coming from, but think you are dramatising this too much.
Even a only 75% "perfect" (perfect from your point of view) Franken M3 will still outperfom most of the usual swap cars IMHO and to me this is still the ultimate swap.

I much much prefer the Franken M3 over some "stuff a V10" in the E30 shell at all cost with butchered subframes and cut and shut manifolds, intakes etc.

a DTM M3 has nothing in common with a stock'ish M3 either. They have fiddled with the suspension points and added a "bastardised" cage to handle the increase in load.

A standard M3 with slightly upgraded suspension and 250bhp on good road tyres is as far as I would take it before substatial improvements need to be made to the shell.
Just add sticky rubber to this mix and you will start a constant stream of repair/replace work if driven hard.

There may not be much left of "M3" in the Franken M3 but I think this is for very valid reasons.