VR6 Widetrack questions

[carpoid 0]

Just been thinking over the last few days....

 

VR's are wider at the front by 10mm each side, right? Does this mean that the rear beam is also 20mm wider? Meaning if i was to put a 24V V6 motor in my G60 on a VR6 subframe and running gear, to do it properly should i put a VR rear beam in as well? Or at least use 10mm spacers on th rear?

 

What is the advantage/is there an advantage of the VRs wider track when the effective offset of the standard wheels is the same? ET43 on the VR puts the centre line of the wheel in the same position as a G60 which is ET33 doesn't it?

[carpoid 0]

Any ideas on this one guys?

[corozin 0]

I'm not saying you won't get a response but I can't lie to you - what you're contemplating is pretty specific and was way beyond my personal knowledge base. I suspect your total lack of responses on this one may indicate that I am not alone!

 

You might want to take a punt by cross-posting your question onto VW Vortex if you havn't already. If you do get to make the changes you'll get applause for carrying it out.

 

Good luck -

John

[Chris 0]

Any ideas on this one guys?

 

to my knowledge yes the vr rear axle is wider than the 16v/g60's rear axle (im not 100% on this). cant help with anymore unfortunately bud

[sim0n_parker 0]

check the bently manual, that will tell u the dimensions of the track in there, or on etka, atleast u can see if the rear axles are dif part numbers,

i woulkd check myself for you but my etka has packd up and i havnt got a bently manual no more.

 

but i am pretty sure that the rear beam is wider.

[s1m0n 0]

Just been thinking over the last few days....

 

VR's are wider at the front by 10mm each side, right? Does this mean that the rear beam is also 20mm wider? Meaning if i was to put a 24V V6 motor in my G60 on a VR6 subframe and running gear, to do it properly should i put a VR rear beam in as well? Or at least use 10mm spacers on th rear?

 

What is the advantage/is there an advantage of the VRs wider track when the effective offset of the standard wheels is the same? ET43 on the VR puts the centre line of the wheel in the same position as a G60 which is ET33 doesn't it?

 

Hi there,

 

Well to answer your questions about the rear beam go over to http://www.clubgti.com they are building a database on beam widths (and other stuff) I think they have dimensions for a MK3 VR beam (which is what I use) but not sure about a C beam.

 

As for the front, VR's are wider (16mm is coming to mind but that could be anything lol..) BUT they did not just bolt on wider wishbones, drive shafts and steering arms!

 

The "Plus Axle" is a complete re-engineered solution, they moved the bottom ball joint out at far as possible (not to mention moving it forward) to change the way the front behaves in roll (etc) then used a wheel with a greater ET (ET43 IIRC v's 35/33 for the 16v and G60), The effect of the greater ET means the track increase is not as immediately obvious, fit "regular" ET35's to a plus axle car to see what I mean.

 

As for front and rear track, it's a FWD car, all things being equal wider front track helps turn-in, grip & handling. Go over to the Seat forum and read posts by RobT and Badger Bill on widening their Ibiza's and the reasoning behind the mods (and their effect). I say these two in particular because they race and by definition are only only interested in "mods" that have a measurable effect.

 

Of course if you just wish to widen the rear for "style" reasons... Do whatever you want lol their are plenty of spacers on gay-bay

 

Cheers

 

Simon

[carpoid 0]

Thanks for the responses guys

 

Cheers Simon, thats making sense a alot more now, i was just interested as to why they changed the set up in the VR, but kept the centre line of the wheels in the same place, (G60's are ET33) i guessed there must of been alot more to it, but was just interested to know, and had never thought about the rear beam until recently.

 

I'm not questioning it for style reasons, i have heard about spacers!! Like i said, if i were to put a 24V VR6 into mine, i would have to use a VR6 subframe and the plus axle etc. Sounds like i should really put a VR rear beam in too. Not too many guys have converted a G60 to a VR, they tend to go down the 20VT route.

 

Cheers all

 

Matt

[Kevin Bacon 5]

Not easy to explain but it's basic leverage and roll centre principles. The wheel centre lines may be the same, but the effective track is still 10mm wider on each side on a VR6. And not only that, if you look at a G60 wishbone setup, the ARB drop links are set fairly inboard. On the VR6, the ARB drop links are right at the ends of the (longer) wishbones as far out as possible for increased leverage.

 

The reason for the ET43 wheels is, I suspect, for wheel arch clearance reasons and drivability. Wide track with the rear wishbone bushes VW used at the time could cause some pretty wayward front end handling. Even though the wheel is pushed back in the arch, the benefits of wide track are still there, but would be more so with ET35 wheels as Simon said.

[Supercharged 2]

The thing with widetrack on a Corrado is that it's a bit of a bodge I reckon...

 

The distance between the turrets doesn't change so they have to account for that...

 

On the MK3 Golf it looks like it was designed for the wide track as the 4 stud cars got longer wishbones than the Corrado's

[Kevin Bacon 5]

You don't have to widen the turret span to go wide track..... look at the Audi RS4, Clio 16V and Clio Williams..... all wide tracked with wide arches, but same turret spans as their respective base models.

[s1m0n 0]

The thing with widetrack on a Corrado is that it's a bit of a bodge I reckon... The distance between the turrets doesn't change so they have to account for that...

 

Laughing... It's a production car of course it's compromised (a "bodge" if you will), you want engineering purity go buy a McLaren (but even that was compromised!).

 

You don't need to widen the turrets to change the track as long as your geometry takes this fact into account, hence my original statement "...they did not just bolt on wider wishbones, drive shafts and steering arms!".

 

Having said that they pushed the ball joint just about as far as they could (outwards) and still had to fit an ET43 wheel to retain a negative scrub radius.

 

So in a way I do agree with your comment but not really for your reasons.

 

VW's front engine / FWD geometry (indeed all manufacturers front engine / FWD platforms that I'm aware of) is based around having negative scrub radius, this is generally regarded as being a positive thing for various reasons. Fitting low ET wheels and / or spacers reduces and / or removes this negative scrub this is not "dangerous" per sae just umm less "pleasant" shall we say.

 

It's a bit of a generalisation but moving the bottom ball joint outwards helps compensate for the fact the top ball joint (mount) has not moved. Scrub radius is a product of wheel centreline and KPI. KPI is produced by the upper and lower ball joints, where a line projected through the upper and lower ball joints intersects (at ground level) with a line through the centre of the wheel you get a scrub radius, either positive, zero or negative.

 

Cheers

 

Simon

[Kevin Bacon 5]

Scrub radius 101 - http://www.familycar.com/alignment.htm#Scrub%20Radius

[s1m0n 0]

Scrub radius 101 - http://www.familycar.com/alignment.htm#Scrub%20Radius

 

:lol: do you think that will help...?

[s1m0n 0]

Sounds like i should really put a VR rear beam in too

 

If you want to go "plus axle" don't be afraid to explore MK3 parts, all the VR's & 16v are "plus", some 8v Gti parts can also be used but you have to get busy with the tape measure to make sure what you have is what you need...

 

This gives you a much greater "parts bin" to pick from (and discourages the scrapping of VR Corrados!)

 

edit - And make sure you match drive shafts, having the "wrong" ones will result in CV failures.

 

Cheers

 

Simon

[Yandards 0]

In answer to the original question:

 

16v/G60 running on 6 1/2J x 15 ET 33:

 

1439mm front track

1432mm rear track

 

VR6 running on 6/12J x 15 ET 43:

 

1450mm front track

1432mm rear track

 

So a VR6 has the same rear track as a 4 cylinder car but given the changes to the ET it is a wider beam. If you consider that they only widened the front outer arches as part of the 'plus' running gear set-up then a wider ream beam had to fit within the existing wheel arches.

 

As for the VR being a bodge into the 'rado; if you consider that the Corrado is an attempt by VW to enter the premium end of the sports coupe market and that they invested some serious effort into ensuring the Corrado handled in a particular way. Then the 'intended' way for a 'rado to handle is the 4 cylinder set-up. The 'bodge' to 'plus' gives a very different feel to the handling of the Corrado (aside from the VR's engine weight being furthur forward than the 4 cylinders) and was restricted by the top turret location - you only need to look at the wider track adopted by the MK 3 Goofs to see that given a fresh sheet of paper 'plus' running gear is intended to run with wider top turrets.

[carpoid 0]

Thanks for that reply mate, only just seen it.

[Lufbramatt 0]

some interesting info in this thread.

 

ive just found teh service manual for the B3 passat, and it has all the suspension geometry in it. notably on the base suspension (4 stud) the scrub radius is 0.5mm with an ET35 wheel, but on plus axle cars (5 stud) the scrub radius is 12mm with an ET35 wheel. So the effect of moving the lower ball joint right out can clearly be seen.

 

However, the downside to the ball joint being deeper inside the wheel is less steering lock due to the inside rim of the wheel moving in a different arc, so the turning circle is increased from 10.7m (base suspension) to 11.3m (plus suspension).

 

Its also quite interesting that the B3 passat has the wide spaced suspension turrets the same as the mk3 golf, but 5 years earlier ;) so the plus axle in its "purest" form was originally developed back in 1988 for the passat VR6, and then grafted on to the A2 based corrado shell for the rado VR6.

[s1m0n 0]

This is starting to get interesting (if somewhat off topic)

 

 

16v/G60 running on 6 1/2J x 15 ET 33:

 

1439mm front track

1432mm rear track

 

VR6 running on 6/12J x 15 ET 43:

 

1450mm front track

1432mm rear track

 

 

I was wondering where these number are from as they differ a little from what I was able to obtain

 

From a Corrado Handbook: -

16v - F 1427 / R 1422 (6x15 ET35)

G60 - F1433 / R 1428 (6x15 ET35 or 6.5x15 ET33)

 

From Carfolio: -

KR 16v - F 1429 / R 1422

9A 16v - F 1435 / R 1428

ABV - F 1425 / R 1380 (which I always took to be an error, I'm feeling a walk outside with a tape measure in the morning!)

PG - F 1435 / R 1428

 

And just for interest, MK3 "plus" from my 16v handbook: -

16v - F1450 / R 1434 (6x15 ET38)

VR6 - F1450 / R 1434 (6.5x15 ET43)

 

but on plus axle cars (5 stud) the scrub radius is 12mm with an ET35 wheel

 

So the Passat plus axle car's came with an ET35 wheel? That's interesting because everything I've seen/read suggested that they only used ET38/ET43 on plus axle

 

Its also quite interesting that the B3 passat has the wide spaced suspension turrets the same as the mk3 golf

 

Corrado is 1084mm, B3 is 1106mm & MK3 is 1116mm so yea B3 almost the same as MK3

 

As for the VR being a bodge into the 'rado; if you consider that the Corrado is an attempt by VW to enter the premium end of the sports coupe market and that they invested some serious effort into ensuring the Corrado handled in a particular way.

 

Agreed

 

Then the 'intended' way for a 'rado to handle is the 4 cylinder set-up. The 'bodge' to 'plus' gives a very different feel to the handling of the Corrado (aside from the VR's engine weight being furthur forward than the 4 cylinders) and was restricted by the top turret location - you only need to look at the wider track adopted by the MK 3 Goofs to see that given a fresh sheet of paper 'plus' running gear is intended to run with wider top turrets.

 

With the greatest respect, I cannot accept this statement. If the C was designed as a 4cyl why is the "VR notch" incorporated into the right hand frame rail (for instance). It's like me saying the C was designed to be Syncro because all the little brake line clearance "notches" are in the rear frame rails and it has a "big tunnel". In reality it may simply be that all the body notches and clearances were "carried over" from the B3 but having said that, (if top mount width is so important) why use the "narrow" 1084mm MK2 Golf top mount position when pretty much the rest of the shell is B3 which has 1106mm top mounts...

 

Do you understand the effect of moving the top mounts in and out (and I don't mean on camber)? Having the (top) mounts closer together increases the KPI (& scrub radius), it also has an effect on dynamic camber gain (loss) but at the dimensions we are dealing with it's slight, finally it decreases the effective spring & damper (wheel) rate but this would be somewhat negated buy the greater wheel offset (less leverage) and of course, they changed the rate's anyway.

 

As for "feel" yes, an ABV is a very different "feel" to a PG, KR, 2E or 9A, have you tried "plus" in a C with a 4 cyl engine?

 

Comparing the C to the MK3 (let's leave the B3 for now) one is a "sporty" low volume coupe the other VW's main "breadwinner", it does not seem too much of an assumption to say they were designed with differing goals?

 

Cheers

 

Simon

[Yandards 0]

This is starting to get interesting (if somewhat off topic)

 

 

16v/G60 running on 6 1/2J x 15 ET 33:

 

1439mm front track

1432mm rear track

 

VR6 running on 6/12J x 15 ET 43:

 

1450mm front track

1432mm rear track

 

 

I was wondering where these number are from as they differ a little from what I was able to obtain

From the VW workshop manual on running gear, it lists all the factory spec wheel and tyre combinations along with their respective track changes.

 

Then the 'intended' way for a 'rado to handle is the 4 cylinder set-up. The 'bodge' to 'plus' gives a very different feel to the handling of the Corrado (aside from the VR's engine weight being furthur forward than the 4 cylinders) and was restricted by the top turret location - you only need to look at the wider track adopted by the MK 3 Goofs to see that given a fresh sheet of paper 'plus' running gear is intended to run with wider top turrets.

 

With the greatest respect, I cannot accept this statement. If the C was designed as a 4cyl why is the "VR notch" incorporated into the right hand frame rail (for instance). It's like me saying the C was designed to be Syncro because all the little brake line clearance "notches" are in the rear frame rails and it has a "big tunnel". In reality it may simply be that all the body notches and clearances were "carried over" from the B3 but having said that, (if top mount width is so important) why use the "narrow" 1084mm MK2 Golf top mount position when pretty much the rest of the shell is B3 which has 1106mm top mounts...

The C has a lot in common with the syncro package, mostly as VW used the stiffening work developed for the syncro on the Corrado. I am not saying that top mount width is critical, what I am saying is that between VW and Karmann they spent a lot of time and money getting a certain feel from the handling of the Corrado, this feel is altered by the addition of the VR6 lump, which when installed in any other contemporary platform is in a chassis intended for 'plus' running gear. I did try to ask the question to the chief design engineer at Karmann when the C was built if he felt the addition of the VR6 and the changes made to accomodate the engine were a compromise on the intended handling characteristics of the Corrado - but he had gone home :D

 

Do you understand the effect of moving the top mounts in and out (and I don't mean on camber)? Having the (top) mounts closer together increases the KPI (& scrub radius), it also has an effect on dynamic camber gain (loss) but at the dimensions we are dealing with it's slight, finally it decreases the effective spring & damper (wheel) rate but this would be somewhat negated buy the greater wheel offset (less leverage) and of course, they changed the rate's anyway.

They did change the spring rates and they also had more than one go at it too, the changes in the top mount design, both on introduction of the VR6 and at Sep 1993 when they changed the springs for the lateral force compensating items in an attempt to improve ride and handling.

 

As for "feel" yes, an ABV is a very different "feel" to a PG, KR, 2E or 9A, have you tried "plus" in a C with a 4 cyl engine?

Sort of and as a what if exercise, using VR6 camber settings and the later style top mounts, it feels like a VR in terms of turn in and steering weight.

 

Comparing the C to the MK3 (let's leave the B3 for now) one is a "sporty" low volume coupe the other VW's main "breadwinner", it does not seem too much of an assumption to say they were designed with differing goals?

No not at all :), you would expect differences in the package and completetly different goals in terms of the finished product.

[Lufbramatt 0]

but on plus axle cars (5 stud) the scrub radius is 12mm with an ET35 wheel

 

So the Passat plus axle car's came with an ET35 wheel? That's interesting because everything I've seen/read suggested that they only used ET38/ET43 on plus axle

 

 

yep they did- my ABF powered passat is 5x100 plus axle and came with the "G60" style steel wheels which are ET35 (part # 3A0601027). The golf VR6/16v version of the same wheels are ET43 (part # 1H0601025N). This gives an overall front track of 1485mm on the passat.

[s1m0n 0]

my ABF powered passat is 5x100 plus axle and came with the "G60" style steel wheels which are ET35 (part # 3A0601027). The golf VR6/16v version of the same wheels are ET43 (part # 1H0601025N). This gives an overall front track of 1485mm on the passat.

 

This thread is throwing up some interesting information!

 

I put B3 4 stud wishbones, drive shafts, steering arms & up-rights onto a C last year, when I compared the B3 4 stud wishbone to a plus axle wishbone I felt they were very similar in size and (IIRC) placed the ball-joint about 16mm further out (each side), I remember "raving" to my g/f about "32mm wider front track...". What track does your service manual give for the 4 stud B3?

 

Cheers

 

Simon

[s1m0n 0]

As for "feel" yes, an ABV is a very different "feel" to a PG, KR, 2E or 9A, have you tried "plus" in a C with a 4 cyl engine?

 

Sort of and as a what if exercise, using VR6 camber settings and the later style top mounts, it feels like a VR in terms of turn in and steering weight.

 

This is line with my experiences, I have a stock VR, a stock 9A both with refreshed (stock) bushes & dampers and an early (no sunroof) KR (now ABF). I am evolving the KR/ABF and I keep swapping back and forth between em to see what the effect's of the "mods" are, it's been quite an interesting process.

 

It's my opinion that the plus set-up works better with the lighter 4cyl up front (compared to a VR), I'm not running this now but for quite some time I just ran all the stock parts I took off the MK3 ABF i.e. the complete MK3 rear beam & complete "plus" front end but with a very cheap and nasty "lowering" spring kit and tired old Yoko's.

 

I think I will be getting the tape measure out at the weekend, it would be interesting to have some actual numbers off cars!

 

Cheers

 

Simon

[Lufbramatt 0]

I put B3 4 stud wishbones, drive shafts, steering arms & up-rights onto a C last year, when I compared the B3 4 stud wishbone to a plus axle wishbone I felt they were very similar in size and (IIRC) placed the ball-joint about 16mm further out (each side), I remember "raving" to my g/f about "32mm wider front track...". What track does your service manual give for the 4 stud B3?

 

Cheers

 

Simon

 

 

front track on the 4-stud b3 passats is given as 1479mm, but with an ET38 wheel. so the track is effectively the same. When i compared them, the plus axle passat wishbones were longer again than the 4-stud ones, but not sure how much by. Also the plus axle passat wishbones use the early I-bolt style ARB mount rather than the bolt through drop links the rado has.

 

[Yandards 0]

As for "feel" yes, an ABV is a very different "feel" to a PG, KR, 2E or 9A, have you tried "plus" in a C with a 4 cyl engine?

 

Sort of and as a what if exercise, using VR6 camber settings and the later style top mounts, it feels like a VR in terms of turn in and steering weight.

 

This is line with my experiences, I have a stock VR, a stock 9A both with refreshed (stock) bushes & dampers and an early (no sunroof) KR (now ABF). I am evolving the KR/ABF and I keep swapping back and forth between em to see what the effect's of the "mods" are, it's been quite an interesting process.

 

It's my opinion that the plus set-up works better with the lighter 4cyl up front (compared to a VR), I'm not running this now but for quite some time I just ran all the stock parts I took off the MK3 ABF i.e. the complete MK3 rear beam & complete "plus" front end but with a very cheap and nasty "lowering" spring kit and tired old Yoko's.

 

I think I will be getting the tape measure out at the weekend, it would be interesting to have some actual numbers off cars!

 

Ah interesting we both reached the same conclusion in terms of feel without actually one of leading the other too much :)

 

I am going to accept the VW workshop manual figures as accurate, given the lack of overall changes in the bodywork of the Corrado, rear quarters for example, then any tweaks to track widths would have to be very minor and the longer VR beam is compensated for by the larger ET of the wheels. I do find the idea of fitting an entire plu setup onto a 4 cylinder car interesting, although I do prefer (and it is a preference) the 'edge-ier' handling on the 4 cylinder setup.

 

Cheers

 

Simon

[s1m0n 0]

front track on the 4-stud b3 passats is given as 1479mm, but with an ET38 wheel. so the track is effectively the same. When i compared them, the plus axle passat wishbones were longer again than the 4-stud ones, but not sure how much by. Also the plus axle passat wishbones use the early I-bolt style ARB mount rather than the bolt through drop links the rado has

 

So it would seem that given the same track (+/- a couple of mm) the plus axle wishbone length change is to compensate for the ball joint being "kicked out" about 15mm compared to the 4 stud up-right. Interesting they use the through bolt roll bar fitting (another thing I did not know!).

 

Cheers

 

Simon