Mk2 Golf IHI track car... Rear body work and door catches

So sad that I've had to re-read my own build thread to remember where I got too... lol

On the plus side at least it's written down for me

 

Nice Build! some great work done to those arches/legs

What's she like for putting all that power down?

 

From what I can remember (its been a while since I drove it ) it was it wasn't too bad with the slicks on. Normal road tyres it was pretty dreadful and with road legal trackday tyres it was pretty manageable.
If you were smooth with the throttle it would behave itself but if your right foot started getting a bit too trigger happy then you'd end up breaking traction and understeering. Once it was moving and up to third gear it was all good

 

damm i thought you had updated this

 

Sorry to disappoint but there is still no progress to the mk2 , as normal I've been kept busy with other projects. The last of which is coming to an end and should be finish early next month.

mk3 pre CGTi Donington Trackday

The Small list of jobs to be carried out were:

Port / polish k03 exhaust manifold
Re-fit new turbo
Baffle ABF sump and convert to turbo
Remove rear seats
Order / fit new front pads
Mount new tyres on 2nd set of wheels
Make new de-cat pipe
Setup corner weights for 2 people - rear seats.
Reset geometry.
Fit new front wishbone bushes and rear beam bushes.
Cut balance weight from O/S driveshaft.
Refit PAS pump / belt.
Change oil / oil filter.
New spark plugs.
Check gearbox oil level.
Get gearbox / sump brace to fit past new turbo oil return pipe.
Replace split servo pipe.

While the turbo was away getting checked / refreshed I bought a cheap porting kit and had a go at porting a standard manifold. I did take some before photos but they didn't come out well enough to see the difference.
Here are the after shots...







Refreshed ko3




The sump.
I had already started doing the sump many months previous but not got round to finishing it. I thought I had more photos of the sump build but don't seem have taken many at all

The engine was and still is a bit of a mixed bag in the mk3. It's a Passat block / head (APU), mk4 ko3 turbo + exhaust and inlet manifolds (AGU), mk3 golf alternator / water pump / pas (ABF) and did have a mk2 16v (KR) sump. I knew the sump had the potential for problems with oil surge and wanted to baffle it before taking it on track. One of the many reasons I haven't tracked it sooner! I still had the ABF sump from the original engine so I started to modify that one (over a year ago lol) while I was still driving the car on the road. The sump is 99% the same shape as the KR sump so I used the KR templates found on the pages of CGTi and transferred them to some alloy sheet and tig'ed them into the sump. The flaps are just piano hinge and flat sheet.





For total peace of mind I then teamed that with a windage tray gasket.





Had a bit of hassle fitting the turbo oil return pipe because I had drilled the holes a little two close to the top edge. I had to take the sump back off and make a spacer then bolt it though from the inside then use nuts to secure the pipe. I also had to re-shape the pipe a little but it all worked out ok in the end with no leaks.

Also extended the turbo bracket to pick up on the holes I had available on the block.



Nothing fancy but it does the job.

The suspension...

Ever since I fitted the coilovers the car has been absolutely horrible to drive! Crashing over bumps, very bouncy at speeds below 60mph but strangely alright at anything above 60mph???

Time to get to the bottom of it...

Firstly I checked the suspension travel. Very quick and super easy to do but before I could do this I removed the totally shredded dust covers.



I had driven less than 100 miles on these and they were all just as bad.

Simply jack the car up, either push the bump stop to the top of the damper piston and then install a cable tie at the bottom around the piston and trim the excess. Then put the car back on its wheels and either bounce the suspension or tack it for a drive. The distance between the cable tie and the bump stop is the amount of travel you have left. To get the most accurate results your better off driving it. I just wanted a rough idea how much travel I had so just bounced each corner.





As you can see I had NO travel left what so ever. I could have taken the springs out altogether and it would have driven exactly the same. The back was the same!

To increase the amount of travel I swapped out the bump stops for some old ones that I cut down.




On the left is the stop that came with the coilovers, the middle is the new old one and on the right is what I cut them down to.

Next thing was to shorten the damper bodies.

The coilovers had the height and pre-load adjusting perches on them so I wound the damper bodies all the way into the mountings.




You can see the silver band on the damper body is much lower on the left hand side than on the right.


Then the last thing I did was to remove the front helper springs to just run on the main spring.

Going from this ....






To this....




Sorted!

Reassembled set a rough ride height and got the wishbones level, then tweaked it to get the diagonal split corner weight right.





It's 1302kg with two passengers, no rear seats and 25ltr of fuel. Still a bit on the heavy side but there isn't much more to come out and even if it was to come out it would only make a few 10th's of a second per lap so it is what it is.
Threw a basic geometry setup on it and that was the suspension done.

Sorted out the split servo pipe with a mk4 golf servo pipe recall kit I had from way back when.




Didn't get a picture afterwards

Then an oil / filter change, a new set of S3 spark plugs and a wipe over with WD40 and she's good to go!



I swapped the tyres on the new set of wheels while the GF gave it a quick hoover and fitted the new carpet mats because "the old ones looked grubby!" lol ok dear carry on..




All loaded and ready to go...



All of the suspension setup / corner weighting was done on the Friday morning before Donington and by the time it was all sorted I never got a chance to test drive it until the 2 hour drive up there.
As luck would have it, it was spot on! No leaks, didn't pull to one side, steering wheel was straight, turbo didn't whistle any more, it wasn't crashing about and drove really nice!
Got to the premier inn near east midlands airport around 11.00pm I think and had an was a sleep as soon as my head hit the pillow!

Awoke the next morning to no hot water. My Sister and brother in law had come up with us the night before as they were going to have a drive as well and they didn't have any hot water in their room either. Had a word at reception while checking out and they refunded both our rooms in full! Apparently the boiler was out and there was no hot water in the building.

On the short drive to the circuit the car didn't feel quite as lively as it did the night before and felt like it was ever so slightly holding back. At the time I thought it was a combination of all the tools / wheels in the back and the cooler night time air the night before and didn't really give it a second thought. As we went out on track it became very apparent that there was a problem with he boost and as I didn't have a boost gauge fitted I had no idea what was going on with it. I suspected it was the N75 valve as it had played up once before and I swapped it for a known good one but it looked like that was also now faulty. Oh well never mind we still had enough power to have fun with but just meant we spent the whole day getting over taken by everything!

We made it to lunch time, the car was going ok and everyone was enjoying the day. I said to the GF that we'll take the N75 off and give it some WD40 to see if that would solve the problem. Soon as she touched it to disconnect the plug it snapped off! I didn't have a spare and was about to rig up something up Adey's mate ( who's name I've embarrassingly forgotten) made a phone call and then half an hour later we had one! Cheers for your help guys and if I see you again I'll buy you all a beer!

After lunch the car had a little more poke but something still wasn't quite right I didn't have anything with me to look into it so all I could do was to carry on as it was and put up with it, which we did. Everyone had a drive and everyone loved the experience, even though it was the slowest thing on the race track. It got round to 4:30 ish and I took the brother in law out for the last session and then 10 min before the end of the day there was a bang and a rattle and then silence.

I knew it was terminal as soon as I heard the bang, threw the clutch in straight away and managed to coast it into the pits and back into the garage. I checked the oil and water and it still had plenty of both were it should be. There was no point going much further until I got it back so we packed up, swapped the wheels back to the road tyres, towed it down to the services just off the M1 and phoned the RAC.

Me:" there was a loud bang and then it stopped! There is no compression and wont restart. It Will need recovering"

RAC bod: "ok we'll send a patrol to see if they can do anything with it"

Me: "I've been a mechanic for nearly 20 years, it's not worth sending a patrol out as I'm pretty sure it's dropped a valve and it'll just be a waste of their time"

RAC bod: "ok, well we'll send a patrol anyway just to make sure. They should be with you in the next half an hour"

I didn't bother arguing as it's probably company policy not to send out recovery trucks willy-nilly and to double check the diagnosis. We had a coffee and a reflection on what an awesome day it had been until the issue occurred and then half an hour later the patrol guy turned up, "yeah needs recovering sir!"

Another 30 minutes pass waiting for the recovery truck and when it turned up the flat bed was covered it diesel oil! "sorry about the mess, the last job had a major engine fault!" I would say so!



Three hours later we made it back and laid a nice big black tyre track of oil down the yard and into the workshop.

Having only just got round to investigating what the failure was I was correct with my first guess...


too be cont..

 

Before removing the head it was quite clear that something wasn't quite right...







After removing the head it was quite clear what had gone wrong...




One of the exhaust valves in cylinder 3 clearly had a problem with it's job and decided to make a break for it. It didn't get very far but it did make a mess of the head and piston. The turbo looks ok but will remain an unknown until it runs again.

I have pistons, I have rods I have a spare head so shouldn't be too bad to sort out.

From the looks of it it's been running a touch on the lean side and what with the valves being hollow the repeated high rpm / high heat it has just pulled the head off the valve and the rest as they say is history.

Plans are already in motion to get it back on the road and I'm going to try and get it ready for the Curborugh Sprint if time allows.


Initial impressions having now driven it in anger I would definitely say that the standard suspension / steering rack rubber bushes really do delay the initial turn in and make the steering really quite vague when running more than standard levels of camber. It's also far to softly sprung for the levels of grip the tyres are able to produce but I only paid 130ish quid for them brand new anyway so I can't really complain. 100 on some new springs and a set of bushes should improve it no end!

All in all there's a lot of room for improvement to be had so it should still yield a lot of fun / quicker lap times even though its not got a lot of horsepower. Looks like I'll be keeping it now. lol

 

Awesome.

Now finish the MK2 dammit!

 

Listen to Alex or you will be 40 before the mk2 is finished

 

So you`ve just used standard Mild Steel Rod to make the drop pin ? I thought they should be a higher quality steel

I REALLY like the machining and work you`ve done, I didn`t know you could buy the COM12 spherical bearing holders off the shelf, that`s opened up a few possibilities for me now

All the work looks good, it`s just the material for the drop pins that concerns me.


Bad luck dropping a valve. You are lucky if it hasn`t scored the bore !!

 

Some really brilliant updates.

On 20vT engines I have pulled apart, the exhaust valve guides suffer from excessive wear, causing the valves to seat in an eccentric fashion. Extended rpm and the forces from snapping shut off the cam profile, can break them off the stem and cause a mess. Really bad guides also wear the valve stem seal and can cause smoke.
My suggestion is, before refitting another head, check the side to side movement of the exhaust valve at full lift and have the machine shop fit new valve guides to avoid a repeat.
Also get the machine shop to check the water channels in the head and correct as required.

PS, that head can be fixed. Although if you have a serviceable alternative, that would be probably cheaper.

Will look forward to seeing you at Curby and even if you cannot make it, I will still be following this thread!

 

lol I've been trying to for the last 3 years!

You don't have to tell me that. It's scary how quick the time goes! I was a young man when I started this "little" job

Yeah it's just mild steel. The plan is that when I'm happy with it I'll weld the spacer to the hub, braze some webs from the hub to the spacer and fit an aerospace grade Ti bolt though the whole lot. I found some when I first thought of the idea and they were about 20 each. It should be ok as it differs from the CCHS type droppers as there is no step / stress raiser and it'll have the bolt going all the way through the joint so even if the spacer fails the bolt will still hold it. I would have liked to keep the spacer just a bolt in piece so I could change it out for adjustment purposes but I'd rather have it fixed for piece of mind.

Cheers for the heads up! I'll be sure to check that on the new head and on this one to see what's what. I've sorted out some Supertech valves as well to safeguard against future upgrades so it shouldn't happen again.

I did look at repairing the head but as it's only a standard head and hasn't had any work done to it it's just not worth spending the time / money on it getting it repaired. I do have a spare AGU head on the shelf that I used in my mk2 for a while that I could fit straight on but I wanted to stay with a small port head as it'll only be running 200-250bhp when it's back up and running and I'd be glad of the extra torque.

I will try and make it to Curby even if its just to "paddock loaf" as it were and to put a few more names to faces.

I might even bring the corner weights to do what I intended to do at Donington lol

 

Weights always welcome! Will add an extra feature to the event!

 

just sat and read the whole thread, I don't know how I haven't come across this before but the work on the MK2 is outstanding hats off to your sir.

but it has been said its time to finish the MK2 off

 

As it's been said and echoed quite a few times I need to get this mk2 back in a drivable condition!

Have no fear! Progress is being made! (If your waiting for the BUT you are correct to do so! )

BUT... The mk3 still needed repairing after melting the head back in March Don't worry I'll keep it brief
With another small port head sourced, obtained, stripped and checked thoughts of "now is the perfect time to port the head while it's all stripped out.." After many hours of die grinder action the head was all ported and ready to be reassembled but then another thought crept in... "If another valve lets go all the porting work will be for nothing..."
Long story short... supertech valves, springs, valve guides and while the head was away getting the new guides pressed in they 3 angle cut the valve seats as well


Shiny stuff...




Swapped out the busted pistons with the old AUM pistons / rods from the rebuild of the mk2 engine...





Gave the bores a quick de-glaze then installed the new / old pistons...



Checked the turbo for damage and found the turbine blades were all bent and broken Found a nice condition k03s and swapped it out. Also swapped out the intercooler for one that's twice the size of the old one and cut a few holes to allow more airflow.



Should help keep the inlet temps down nicely.


After all that it was a simple case of welding up the massive hole in the passenger foot well that someone had made a really rather good fiberglass repair too.
I know... where did that come from right?!! Where the sills meet the floor looked a bit flaky and didn't quite look right but never showed any rust (being fiberglass how could they lol) so I just left them as they were. To get it through the MOT it just needed a little patch on the floor round one of the grommets, 30min job tops. Then that little job quickly turned south and after an hour of cutting, grinding and other operations it looked like this...




Forgot to take the after pics but it all looks as it should now... apart from the wing that's rotten and now has a "vent / brake ducting" instead of actual metal. Being a black car it doesn't notice as much as I thought it would but until another black wing presents it's self for sensible money it'll do fine.




That's about it for the mk3 at the moment...




mk2 update part will be tomorrow

 

mk2 Time


It's been roughly 8 months since working on the mk2 properly so as you can imagine it's taken a while to get back into the swing of it. After reading my own build thread once or twice to re-jog the now getting older grey matter it all started to come back to me.

So what to do next...

In the very beginning the idea was to model the suspension in 3d to see what the kinematics (movement of the suspension) were like and then improve / make best compromise from there on but the software couldn't model the whole car only the front. This was because it didn't have the rear beam suspension design, that VW and almost all other manufacturers have used at some point, stored in it's data base??? It would still do a great job on the front but was half a job going to be good enough to warrant the expense or would it be better to save the money and spend it on actual parts? The deciding factor was the demo trial. After downloading and installing the time came to finally input the data and see some pretty moving pictures! "Wait a minute... whats all this X,Y,Z b@ll@x!!???" After reading the actual manual and not just watching the glossy advertising videos it made sense. The positions of the pick-up points needed to be entered in a CnC style coordinates. After receiving a reply to the email I sent asking about the best way to go about measuring these coordinates the answer was "you need a CMM machine". Awesome! What on earth is one of those?? A quick google and it turns out its a Coordinate Measuring Machine perfect!!! How much and where can you buy them from!?? As it turns out they're silly expensive and not many places sell them so there aren't that many second-hand units about. With this new information the thought of spending even more money on something that will still only model half the car didn't really seem worth it, so the idea was put to bed and that's when the string computer was built.

The string computer worked really well for positioning the roll centre, it wasn't that user friendly in the scale I'd built it but it served it's purpose. At the time the understanding was that the roll centre needed to be raised to decrease the distance between it and the Centre of Gravity (cog) to reduce roll from geometric weight transfer. This would work but the trade off is that the jacking force of the car trying to "pole-vault" about the outside tyres causes un-wanted lift on the inside tyres and is therefore undesirable.

The only available option was to keep the roll centre where it was and then to lower the Cog.

After re-reading my thread I can see that I had the right idea but for the wrong reason. I was concentrating on just the roll centre and not the relationship between the two.

In a nutshell -- The if the car was lowered 50mm then the roll centre needs to be raised 50mm

eg. if the distance between the CoG and R/C = 100mm to start with after lowering the car 50mm it will still be 100mm

So if you then raise the R/C 50mm it decreases the distance to 50mm

(granted it's not going to be exactly the same due to the specific geometry changes as the suspension moves down but you get the idea )


What's the point to all this??? Simple answer short... it reduces load on the tyre contact patch. It's really that simple. This took quite a while to sink in. It's the tyre that generates the grip and if it's at it's maximum load, it's at it's maximum load.

If only I knew then what I know now lol

So where to from here???

Looking at it with fresh eyes it was time to do what I should have done back at the start and take some measurements. Even if they were just for reference at a later date, doing it now would be better and 100 times easier than with it all back together.


The engine and gearbox were only just sitting in there to get them out of the way so it didn't take much to remove them to allow for superior access to the floor under the car.

Drilled one hole in the middle of an old subframe bolt and one at 90 degrees to it to allow for a plumb line to be fed through. This would give as close to the centre position of the hole as possible with the tools available at the time.





The floor was then cleaned with a wire bush and a squirt of brake cleaner, a piece of masking tape placed under the bolt hole being measured, a plumb bob fed though the holes in the measuring bolt and then finally the position of the plumb bob transferred to the masking tape.




This procedure was carried out for the wishbone bolts, subframe bolts, top mounts and the bottom ball joints.

With these measurements it was possible to work out the X,Y coordinates for the pick-ups / mounting points. By halving the distance between the two sides would give me "Y zero" reference plane and I used the two rear wishbone bolt positions as my "X zero". All that was left was to measure the heights and that would give 3D coordinates of the front suspension without the use of a CMM machine.

Re-fitted the front suspension sorted out the height measurements...




A substitute "Z zero" was added (the silver rail with holes in it) because the ground isn't quite level and all the measurement data was recorded.


Having all the data gives the option to fully model the suspension kinematics if the chance ever provided its self.

It also allowed the conformation of the amount of scrub radius with the help of a few CAD drawings...




It is what it is, good or bad I've no idea but from what I've read it's less than 25% of the width of the tyre so shouldn't cause too much of a problem.


With the front suspension back on both front steering arm tapers were drilled out to take the bolts for the rod ends, the rod ends fitted to the rack and wound on the same number of turns.
The rack was then centred by removing the rack boots and setting left & right stick out equal with a pair of dividers the tracking was then adjusted and set to parallel.




This gives a nice equal level base to start from.

From here on the next move is to check static camber + caster and adjust if necessary.


It not much but it's a start

 

Awesome work.

 

Had a few hours to start looking at the camber and caster tonight.

Caster gives the ability to run a small amount of static camber but increases that amount when steering lock is applied. This means that the front wheels are more upright in a straight line (which is good for traction when accelerating / breaking) but still give good camber gains when the wheels are turned for cornering. The only down side is the more caster the heavier the steering. There is also a problem when the angles start getting extreme but I can't remember it at the time of writing this????

To check the caster you take two measurements, one on 20 degrees of right steering lock the other on 20 degrees of left steering lock. Then add the two together. Its the total change your looking looking for so even if you get - value it's still treated as a +.

Taking these measurements was going to mean moving the rack from left to right quite a few times so to make it easier to get the rack back to center I make a precision spacer that fitted over the rack and acted as a stop. Nothing high tech just a lump of alloy turned down to 43mm (I think) in length with a 19mm slot though it.




This slots over the rack behind the inner track rod joint like so...



Turn the rack a little to the left, drop the spacer in, turn it back to the right until it locks it in place and then slide the spacer up and off the rack. Allowed for consistently repeatable starting point for the measurements.

Next job was to record the 20 degrees of steering for right and left locks. If the car was on the ground it would have been easy as normally you just drop it on to some turn plates and Bob's you uncle! As luck would have it there were two scrap batteries that we had changed over the last few weeks which when added to two blocks of wood added up the exactly the right height to put the turn plate on.





Zero the scale...





Take the static camber reading ...



Camber readings are the BLACK scale Caster readings are the GREEN scale. Just looking at the camber in this pic. This was the 6th position of the potential top mount location.

Was 1.25 degrees negative. Looks less in the pic as I didn't quite get the camera at the right angle. (parallax error )

Now for the first caster measurement at 20 degrees of right steering lock ...



This was 4 degrees (now on the green scale)

Now for the second measurement. Turn back to center then too 20 degrees of left steering lock...




3.75 degrees on this one

Now adding both measurements gives the total caster. 4 + 3.75 = 7.75 degrees.

I was aiming for around 7.5 caster with the least amount static camber. The hubs are in the maximum positive camber position they will allow but there is a little room for fine tuning by grinding the hubs down a little.

In total I tried 6 different positions and have a range of caster from 3.5 degrees to nearly 10 degrees so there's plenty of room for adjustment.

Here are some of the various positions tried...





With the caster somewhere near where it's going to be spring + shock to body clearance and spring + shock to wheel were checked...






The 9+ degree position just runs into clearance issues as the spring start to rub the body work.





The red bungee cord was used to hold the assembly from moving around while doing the lock to lock part. Seemed to work quite well.

So what's been achieved by all this??

1) The range of caster has been established.
2) The approximate location of the top mount has been established.
3) Possible interference issues have been identified.
4) Current locations of raised top mounts will provide sufficient adjustment range ( really glad it did, was dreading having to cut them back out again)


Up next is where it all gets a bit technical. The wheel frequencies, suspension travel, motion ratios and roll/g need to be worked out to determine what dampers will be needed and where to get them from???

Also need to re-install the engine / gearbox to check for clearance on the driveshafts now that the wheels will have moved back slightly.

 

nice work, interested in the "wheel frequencies, suspension travel, motion ratios and roll/g" bit!

 

Top work and thanks for sharing. End of 2016/17 will be the return of the mk2 on track?

 

Really enjoyed reading that

Should lead to a cracking car once done.

One thing to note, I know why you are trying to keep the static camber small but won't radial track tyres and slicks still need around 3 degrees or more to be able to generate the correct slip angle in corners?

Gurds