Cope's GTI - Page 5

Topic: Cope's GTI (Read 10427 times) previous topic - next topic

Re: Cope's GTI

Reply #60 – December 21, 2022, 04:50:34 PM

https://www.youtube.com/watch?v=qhogBIXE5Bk&t=195s

Re: Cope's GTI

Reply #61 – March 27, 2023, 02:07:37 PM

It’s been a while since I updated this, I’ve been deciding what to do with the engine, and for now that project is on hold, the 8v will live for another year!

After photoshopping out a yellow Fiat 500, I got one of the photos from the Nurburgring printed and frame, somehow I managed to get it pride of place in the lounge! The missus said she “likes the greenery” suits me [

]

I got the Golf out last week on the drive, first time it’s been started since October, as expected she fired straight up.

Unfortunately, the headlining has taken a massive turd.

So I’ll be trying some spray adhesive to fix it.

She should be out for April, providing all the salt has buggered off.

Re: Cope's GTI

Reply #62 – March 27, 2023, 04:07:17 PM

Bumpsteer and Roll Centre Correction

This has been a big item on the list for quite some time now, and it’s going to be interesting to see how it will effect, what in my mind is already a well handling car.

This post is fairly in depth and fairly nerdy… if that tickles your pickle stay tuned.

I chose to start with the Noath Engineering Roll centre correction and track rod flip kit. A lot of the off the shelf ones I don’t like the look of and I’ve heard numerous stories of them failing. The main reason for this kit was it was tried and tested on Nige’s golf, and they use really high quality materials.

If you look at the angle of the wishbone it gives you an idea of the roll centre, before and after the kit.
OEM at ride height

Noath Kit at same ride height

With roll centre you are limited by the size of the pins you can use in the BBJ, for interference with the wheel, especially on 15’s.

Now onto the track rod flip kit, I was thinking about fitting the kit and leaving it at that, but curiosity got the better of me and I wanted to work out exactly what the factory bumpsteer was, in comparison to the kit.

At this point I want to just reference Nige’s website for those who haven’t seen it, a lot of what I’ll be going through here, he has covered. www.pinderwagen.com

So, bump steer. What is it? and how do you measure it?

Bump steer to put simply, is unwanted toe change through a cars suspension travel. The changes can be pretty crazy, and this can cause unpredictability in handling – especially on track, where you will naturally use more of the suspension travel due to the forces.

Bumpsteer is effected by the arc created by the lower ball joint mounting point and the track rod mounting point, and their relationship to each other. – its almost like a push and pull effect.

How do you measure it? There’s a few ways, you could take it to a specialist, who will no doubt charge you an arm and a leg. There’s a Longacre gauge, which are upwards of £600. Which again isn’t feasible for us ordinary folk. And where is the fun in not learning along the way!?

Taking inspiration from the PinderWagen, I used 2 sheets of flat wood. I bought these from B&Q for £10 – much more respectable!

Before you do anything it’s important to take some initial measurement. With the front bumper and front wing removed, it gives great access to the suspension.

This is how I measure ride height, using a bolt in the hub and a block of wood on top of the inner wing. It’s also a good idea to measure the front sill to floor height at this point.

Next up you need to remove the front spring, this makes life a lot easier when jacking the suspension up and down.

Next up is to drill out the bolt pattern so it can be mounted to the hub.

The wood was cut into 2 pieces, one will be bolted to the hub, the other will pivot off the floor, and the distance between the leading edge, throughout the suspension travel is where we will measure the bumpsteer.

There’s a few ways to measure it, you can use a steel ruler – time consuming and has ability for inaccuracies. Vernier calipers are another option, much more accurate but again a bit of a faff, measuring and remeasuring.

I chose to go for a dial gauge, they are fantastic, measuring 1mm through one full rotation of the dial, they are also very inexpensive, this was £8 on amazon.

The gauge needs mounting to the wood, I used an old GoPro mount – this worked out really well.

on the other side of the wood, mirror the length of the gauge with a bolt. This will remain constant and make any measurement visible on the gauge.

With everything ready to go, and the front wheel off, I lowered the car back down on the jack so it was the same height as the sill to floor height we measure previously. I don’t have 2 jacks and axles stands are too high, so I used the standard scissor jack to keep the height of the car consistent. My main jack I used to raise and lower the suspension.

The standard set up was then measured.
The best way I found to measure this accurately, was to jack the suspension up to ride height. The dial gauge was then zeroed. I then jacked the suspension up to full compression, released the jack slowly and filmed the dial gauge on my phone.

With the results filmed on my phone, I could sit inside and plot everything on a graph.
The straighter the line, the closer it is to zero bump steer.

To explain the above:
X axis – Shows toe change in 1mm increments, toe in to the left, toe out to the right. (each small square on the graph is 0.05mm)
Y axis – Show suspension travel in 10mm increments, from full extension, through ride height to full compression (each small square is 0.5mm in travel)

The suspension was jacked up and every 10mm a dot was plotted on the graph, with a line of best fit to see it visually.

What we can see in this standard set up is we gain toe in as the suspension extends from ride height and gain toe out under compression.

In driving terms, toe out gain under compression isn’t necessarily terrible, certainly more favourable than toe in, which I think is why the car felt pretty good anyway. – But we are still seeing over 3mm of toe out at 40mm compression, which is significant.

So how does the Noath Kit compare?
Well, as we mentioned earlier, the relationship between the LBJ and the track rod is what effects bumpsteer, so if you were to just fit the extended ball joints and keep the track rod as standard the bumpsteer would be horrendous, quite literally unmeasurable!

I’ll also point out at this point that bumpsteer is bespoke to each car, there’s no one size fits all. Noath doesn’t sell this as a ‘bumpsteer kit” the idea of flipping the track rod is to get the bumpsteer back towards oem, as best they can for a bolt on kit.

This graph shows the Noath kit, as it is, as you can see its actually worse for bumpsteer than the oem set up. So although we have corrected the roll centre, that has now had a direct effect on bumpsteer and made it worse.

The red line on the graph shows the track rod end lowered 5.5mm using washers, this was to see which way I need to move the track rod. As you can see the redline is worse still.

With that data collected I had to work out a way to move the track rod up. I could cut down the misalignment spacers Noath provided, but there was a casting on the track rods which would need to be ground down.

Going over the graphs again, I’d worked out I’d need more than just a trim of the spacer.
The only way would be to trim the hub to get the desired height.

This caused another issue, the Noath kit comes with a tapered bolt which is great for a direct bot on kit but if I had to trim the hub the bolt would no longer sit correctly in the tapper.

So I decided to drill the hub out to M14, and use an M14 rose joint instead.

These were from McGill Motorsport, ordered on Friday afternoon, arrived Saturday!
I ordered their highest quality joints, misalignment spacers and rubber boots, costing £45.

With the hub drilled out, I took 6mm off the hubs. The material I’ve taken off the bottom I’ll add back on the top to retain the strength in the arm, I’m just waiting for the steel to arrive.

After the material was taken off and cleaned up, I cut one of the misalignment spacers down to 4mm and assembled.

I checked the articulation of the joint and there was still plenty of room and no binding in the joint.
I then plotted another graph:

The above results I was absolutely chuffed with!
Red line is: Modified hub with M14 Joint, 4mm misalignment spacer
Blue line is: Modified hub with M14 Joint, 4mm misalignment spacer and 2.3mm washer
Green line is: Modified hub with M14 Joint, 3mm misalignment spacer

Looking at the data, the red line seems best for me, although green looks best on rebound, Red has the most usable area in zero bump, with up to 0.5mm of toe change over 82% of suspension travel.

The reason the graph arcs to toe out at the extreme ends of travel is because the track rod is effectively too long, the solution is either a wider rack, or fit rack spacers.

That will be version 2 of this project and for now I couldn’t be happier!

For those wondering I did some back to back test, and each data point was accurate to within 0.1-0.2mm,
I’ll settle for that with a DIY setup at a fraction of the cost!

Now I've just got to repeat on the other side.

Re: Cope's GTI

Reply #63 – March 28, 2023, 08:41:27 AM

That is brilliant!
I really love the way you're evolving your car as well as your skills.
And also pinching ideas off Nige!

Re: Cope's GTI

Reply #64 – April 13, 2023, 05:18:36 PM

Managed to get all the bumpsteer adjustment finalised.

I’ve made a 10mm spacer from mild steel, with a tapered end, so I could get some decent penetration when welding.

This was then bolted up tight and welded to the hub

Cleaned up and painted

The process was then mirrored on the passenger side.

Next on the list was to get the car ready for MOT.
I knew the front jacking point was a little suspect, so started stripping off the underseal.

I decided to chop the lot out and reuse the cup, as that was still decent metal.

First up was a card template followed by a steel replacement

Once I was happy there, I rewelded the cup on to the new metal.

Next I heatgunned the floorpan to get as much waxoyl out before welding. This makes a big difference to the weld, but its still managed to creep through when welding.

Once in, it was etch primed, painted and undersealed.

Once that was sorted I fitted 2 new genuine rear mk4 calipers, as one of mine had a sticky handbrake mechanism.

And that is everything for the MOT. So we will see how that pans out tomorrow! Fingers crossed.

Aside from that I’ve also tackled the sagging headlining. The repair was a bit of a do or die situation as I cant get it out for the cage.

The plan was to peel it back as far as possible to the main hoop on the cage and restick.

To get the best adhesion, I spent some time removing as much of the dusty foam on the headliner fabric, I found the best solution was to rub it off with your hands.

The board was then coated in PVC glue overnight, again to try and give the fabric the best chance of adhesion.

Once the PVA was dry I used a spray adhesive, to restick the fabric.

Very happy with the results! But only time will tell if it can withstand the heat of summer.

Re: Cope's GTI

Reply #65 – April 14, 2023, 08:27:32 AM

I really hope your trick with the PVA works. I did that to mine about 3 years ago (using paper mache as well to add structure).
Last weekend I fitted the fiberglass ebay headliner as it started to droop again after about 2 1/2 years!

Re: Cope's GTI

Reply #66 – April 27, 2023, 05:54:51 PM

With most jobs now ticked off, the only thing left was some new brakes for the MOT.

I fitted 2 new genuine VW mk4 rear calipers, these had been rebuilt with new seals and pistons for a bargain price of £70.The old calipers were well past it, one was a pattern part and the hand brake mech had seized so I’d only had one caliper connected up to the lever.

When it came to new pads, I stuck with Tarox Strada for the rear - these have been brilliant, they have the same bite as an OE pad, but can take much more heat – perfect.

For the fronts I’d decided I wanted to try something new. I’ve used DS2500’s for years and I cant knock them, always rock solid and can take lap after lap without fade.

However I’d heard such good things about other pads I fancied a change.

After doing loads of research and chatting to some mates, I’d settle on Carbone Lorraine RC6’s, these had a better coefficient of friction at 0.5 oppose to the 0.46 of the DS2500’s and could take over 1000 degrees C.

With my order placed, I had a call from CL, they were unable to get any RC6’s from the factory for my G60 calipers, but they did offer me a free upgrade the RC8’s…

in for a penny, in for a pound!

These are a real bit of kit! I was sceptical about going for such a high end pad, as I still use the car on the road. After doing some digging I found out they are 0.6 coeffient from clap cold. So the initial bite should be fantastic.

After everything was fitted I gave the brakes a full bleed with ATE type 200.

I went out that night to bed the pads in, 70mph down to 20mph medium brake pressure 25 times in a row.

It's safe to say I’m totally blown away by the pads, theres so much feel and the initial bite wants to rip your face clean off! I’m looking forward to trying these on track.

Pads fitted, time for MOT.

It's always a nervous wait, but I’m pleased to say she passed with flying colours and no advisories.

Once passed I went for a blast out, the new bump steer correction and roll centre correction mods have made the car feel alive! The steering is so precise and it feels like I need less lock. So I’m very very happy. Can’t wait to try it out on track!

My only complaint after driving the car, aside from the squeaky brakes when cold – which I can live with – is the pad knock. Because they are designed to take so much heat and expand in the carriers, on the road they knock and clatter about.

I messaged CL to see if they did a spring kit for the pads, the response was “it’s not deemed necessary on race cars” … which is totally understandable!

So I’ve retro fitted some spring from a set of old rear pads.

The springs were drilled out, adjusted, the hole in pads was also drilled out and then the springs riveted to the pads.

I’m yet to try the car, but I’m hoping that’s cured it. Once the pads wear down I’ll have to remove them as they will come in contact with each other, but I’ll work another solution for that when the time comes.

I helped out again this year at Elsecar at The Races. Simon asked if I wanted the Golf inside this year… This was the excuse I needed to give the car a much need clean up and polish.

I always try and keep it looking the best it can, but artificial lights show every imperfection.

So I busted out the machine polisher and got busy

I used 2 stages on this, medium pad and a refining pad with Menzerna products.

I went to town on the bits I’d painted, but just did one stage on the places that are still in original paint. There’s not much paint left to polish and its getting very thin on the rear quarter.

It was nice to spend the time making it look really clean again!

I parked up next to Rob in his incredible mk2, this is the same Rob that does track days with us in his S3

I’ve booked Donnington Park on the 2nd May to kick this years track days off.
I’ve never done Donny so I’m very excited to see how the car feels with all the new upgrades.

Re: Cope's GTI

Reply #67 – April 28, 2023, 08:15:54 AM

I used to run the CL6s.
Loved the performance, but couldn't stand the squeal on the road.
Couldn't seem to get them up to temperature on normal road driving.
They now only come out when I have track days.

Re: Cope's GTI

Reply #68 – April 28, 2023, 11:35:52 AM

The Jackie Stewart steering wheel really looks the part. A great choice of tiller.

Re: Cope's GTI

Reply #69 – May 15, 2023, 05:39:45 PM

Donington Park 2023

After all the recent modifications, I was excited for Donny and to see how the car performed.

After a 2 hour drive, we arrived. My mate Jim in with me as passenger, Brooke in his e46 touring, Rob in his S3 and Dunc in his Clio.

We are getting pretty good at this track day lark, along with an F1 team assortment of spares and tools, we added a kitchen to the list of “must-haves”– Yorkshire tea, Ginger Parkin and chocolate Hobnobs to boot!

The day went really well, slowly picking up the pace.

I was soon taking Craner Curves flat in 5th, the car felt really planted and I often found myself catching a lot of fasters cars through this section and the old hairpin.

One thing I struggled with in the morning was the brakes, They bite so hard its unbelievable, and because I’d got new brakes I was trying extra hard to brake as late as possible and as hard as possible, which resulted in a few lock ups. Luckily my brain engaged, came off the pedal, quickly back on then easing the car into the corner without getting too out of shape…

Whats amazing is, 5-6 laps in they just get better and better.

After a session I noticed the brake reservoir, was completely cool to the touch, which shows just how effective the copper backing is on the pads at managing heat.

The Golf kept battling on lap after lap, without issue.

I was really pleased with how the car felt, the steering is like nothing I’ve driven before, so precise and accurate, it was well worth the time and effort correcting the rollcentre and bumpsteer. The only thing letting the side down were the tyres. As good an all rounder as NS2R’s are they just don’t provide the grip, particularly on corner exit that you really want.

Having said that I was catching some expensive metal and had good battles with an E36 M3, a fully bazzed up M4 Competition and this amazing E30.

It was a 1989 320i and according to James the owner it was 128hp and 1,000kg. Which explains why this and the Golf were so evenly matched! Even in a straight line, which never happens!

They seemed to just get the edge on corner exit, and as usual I was probably pushing a little too hard for the tyres (I'll address that soon!)

But here you can enjoy a few laps with the E30.
I’d borrowed a newer GoPro 8 Black, and the quality was fantastic, so I’ll be investing in a new camera shortly, and using my GoPro 3 as a footcam

https://www.youtube.com/watch?v=bQIXhqzl2To&t=113s

*disclaimer* The Porsche at the start of the video had held me up numerous times in the day, every time I’d catch him, he would fly off, before the next corner, clearly the thought of an old brick shaped Golf getting past his beloved Porka was too much to stomach, so I’d decided to just drive as close as I dare and hope for a blue flag… it can get frustrating. For those who don’t know on a track day, if a car approaches you from behind, they are faster, it doesn’t matter what it is. Indicate, back off and let the other car past. It’s a very simple concept, a lot can’t seem to fathom.

Unfortunately for Rob, just before the end of the day, the pistons in his S3 decided they didn’t want to be in an engine anymore! So that was end of play for him.

Before we knew it the day was over! It was probably one of my favourite track days, Donington is fantastic! And we had some really good laughs with some really good lads. There’s not much more you can ask for!

Since the track day I’ve been using the Golf as often as I can, I’ve been over to the Motorist a few times, which is always good!

And someone took some nice photos

Next on the list, is another set of wheels and a set of slicks! Lets see how many CVs/Gearboxes I can break…

Onwards and upwards!

Re: Cope's GTI

Reply #70 – May 15, 2023, 07:57:19 PM

I love how you always drive this on its limit! I did an evening at Donington the other year and had a great time, I'm quite cautious and found I was busy stayout of others way 😳 but it's great when you find something to battle with

Re: Cope's GTI

Reply #71 – May 16, 2023, 09:04:56 AM

Always enjoy reading your updates James.
Great to hear how your effort on the bumpsteer and rollcentre has improved things for you, makes me very tempted to get the spanners back out on mine.

Re: Cope's GTI

Reply #72 – June 21, 2023, 05:11:25 PM

Nurburgring Trip is booked for the end of August for 11 days! Very very excited for that!

I’ve been tinkering away slowly on a few jobs. First the scuttle has needed attention or years, I previously repaired it when I was 16 with fibreglass… yep… but to be fair, it was all still intact and the rust hasn’t spread.

I also need a new windscreen, as this one has a few chips and some grinding splatter in the glass. The old seal was cut out and the windscreen removed.

The next step will be to remove any other bits of surface rust, etch prime and paint.

Another reason for the removing the windscreen was to make some gussets for the roll cage.

I always liked how they look and should provide loads of extra stiffness in the shell. As with most things, I’m picky. You can buy sheel steel with the dimples already made in a precut piece. I’ve never liked them as they never fit 100% and feel like an after thought.

I’d made a few CAD (cardboard aided design) templates and settled on this.

I wanted the angles of the piece to match the roof line at the top and the speaker covers in the dash at the bottom. I bought a 25mm punch and a 25mm dimple die.

Both incredible tools! And very reasonable at £10 a piece.

Once I was happy I started making them in steel

Another cheap but incredible useful tool! A deburring tool, used for, you guessed it... a bargain for £7
Dimples were then added.

If you don’t know, the dimples add loads of rigidity to the panel, whilst also reducing weight. Win-win!

Once I was happy, I protected the car from heat/welding splatter as much as possible, using a welding blanket over the dash. I also ali tapped the roof gutters just in case. I’d have been gutted if these were damaged!

Then pen marked where I wanted to stitch weld, making sure to weld inbetween the dimples to give the most strength.

All welded in.

The process was repeated on the other side, then etch primed and painted satin black.

All done!

Very happy with the results. I wasn’t too happy with the welding at first, I’m getting better but by no means perfect. Luckily I’m pretty good with a grinder! lol

Next up will be finishing the scuttle off, and if there’s time before the Ring, I’ll also be making gussets for the b-pillars.

Re: Cope's GTI

Reply #73 – June 22, 2023, 08:39:34 AM

Quote from: Cope on June 21, 2023, 05:11:25 PM

I’d made a few CAD (cardboard aided design) templates and settled on this.

Someone's a fan of project Binky!

Re: Cope's GTI

Reply #74 – June 29, 2023, 01:19:36 PM

With the gussets done, the focus was back on the scuttle. Another fibreglass hole was revealed near the wiper. This was cut out, and a some fresh sheet welded in.

The scuttle was then keyed with 400 grit paper by hand, making sure to get into the gaps in the panels. I’d managed to get a trim tool under the roof gutters and lift them up enough to get some masking tape under them, which worked surprisingly well!

Etch primer applied in a can, wet sanded with 800 grit ready for 3 coats of base coat, followed by 2 coats of clear.

Really happy with the finish. There is some dust in the clear which is inevitable without a proper booth, but I should be able to wet sand these out.

The image below is straight out of the gun.

One thing I’ve learnt from painting a few things now, is in the clear coat. The clear I use recommend a 2-1 ratio of clear to hardener with 10% thinners, I’ve found this doesn’t flow through the gun well and it doesn’t really atomise very well. I use around 20-30% thinners in the mix, and the paint seems to go on really nicely! Obviously, you run more risk of runs, but it's a lot less work after wet sanding and polishing.

I’ve also picked up a new windscreen, this one is a factory green tint with a blue top tint band.

I can confirm a mk2 screen fits in the back of a e36 BMW with about 3mm to spare 