Budget DC2 VTi-R Track Car

[RC_dc2]

Nice work! Hopefully that resolves the braking issues.

Thanks.

I really hope it does, I've spent as much time and energy on the brakes as I want to right now so I'm keen to get some reliability happening.

I could always drive slower I suppose...

[RC_dc2]

Time for another update.

After the car sitting idle for a long time I thought it was time to get it out of the garage. After not starting the car for near 8 months it needed some fresh oil and fuel. It got treated to some Penrite 10 tenths 10w-40 and re-bled the brakes with PBR RF600. After only about 2 cranks it fired up straight away and idled nicely, took it for a short drive to bed the brakes in then back into the garage for some final checks before heading out to Sandown for the Maserati Trident Track Day.

I did a torque check of all the suspension and subframe bolts, I found a couple that needed re-torquing but overall everything was still good. I was hoping to get some brake ducting finished before the track day but as usual everything came up a lot faster than I thought, I had to go away for work during the preceding week and it just got away from me. I managed to get a few things fitted last minute:

Steering wheel - Velo R90, 350mm Diameter 90mm dish. This is much better for reach than the stock wheel and has so much more grip. For reference if anyone tries to sell you an HKB OH-207 to fit a DC2 just skip the hassle and get the OH-215 even though HKB's own listing doesn't list it for the DC2 <98.



Dorian Mount - I messed around last time with tape and cable ties, this makes it so much easier to just clip in and go. I mounted it under the boot floor because it was protected a bit from the track and easy to get to. I couldn't find an easily accessible place closer to the front or middle of the car that was protected.



On the day I was hoping that my brake problems from the last outing would be a bad memory, but unfortunately it was the same if not worse. As soon as the brakes are warm and any kind of medium/hard braking is tried there is extreme shudder. So much that if you don't grip the wheel with both hands you might lose control, needless to say this was extremely disconcerting and wasn't conducive to quick lap times.

I tried a session with ABS disengaged as this seemed to help the pads bed in last time out and the shudder went away by the end of the day, this time it didn't help. I took a good video of a mishap coming into turn 1 on this session, I managed to catch it in time....

https://youtu.be/A1apQLKuwnc

On another session I came back in to find my passenger indicator housing hanging out of the bumper by the wires. I didn't hit anything or go off the track, the screw that holds it in had somehow fallen out. A bit of tape held that in for the rest of the day, luckily the wiring is fairly strong and everything still worked.



The wear on the rotors was interesting, the pads must have a bit of taper because they were not wearing the rotor evenly. They are obviously getting hot due to the colour change near the inner diameter, this section eventually started bedding in but even the rest of the rotor wasn't showing much wear.



There was quite a bit of traffic on the day as well as a mishap on our second session which left oil on the track on every corner from 4-11, the track was closed for nearly an hour for the cleanup and then we were advised to take it easy when it opened back up due to the oil. Although you could see the spill and cleanup all over the track it turned out that it wasn't too bad.

I was really disappointed for the most part, I couldn't push the car like I wanted due to the brakes and my lap times were rubbish. In the last session I decided to just put it out there and give it all I could, I managed to keep my teeth from rattling out of my head and also made a new PB.

My previous PB was 1:31.48, new PB 1:30.78!

Here's the lap timing from racechrono, there is still some work to do especially coming into turn 6.


Don't ask me how this happened, I was actually pretty surprised. If I could actually brake where I wanted to I'm sure I could squeeze under the 1:30 mark.

The video of the PB lap - I used dashware to overlay the racechrono data, I couldn't get the gps timing to sync up exactly. The time listed is the dorian, racechrono recorded a 1:30.85 with a 10Hz transmitter.

Positives out of the day:

- Having the tablet with Racechrono visible on the dash was very helpful, I think this helped me lower the lap times. At one point I was only concentrating on keeping it steady and following my lines and I glanced down and saw I'd equaled my old PB when I was seemingly going very slow, this inspired me to push for the next couple of laps when I managed to better it.

- Having the GoPro setup was awesome, this is the first time I've had footage to watch afterwards to see another perspective of what I'm doing. N.B it looks a lot slower in the video than it feels on the track

- The new steering wheel setup was great, reach is much better than the stock setup and easier to grip.

- I didn't boil the brake fluid (probably because I couldn't step on the brakes hard enough due to the shudder!)

- Managed a PB even though most of the day was a shocker.

I would like to say the brake upgrade was a positive but I cant really judge due to the shudder. The next step is to replace both hub bearings and check the runout to see if this fixes it. Note that at street speeds the brakes are perfectly fine so it is something that may not show up immediately and it is hard to test for without full track conditions. I drove home from the track no problems and there are no vibrations at speed before the brakes are applied.

Random shot of the car on the day, the battery triangle was required in the supp regs. I looked at getting a magnetic one that I can easily remove, my mate got one but it needed to be taped down anyway so I just stuck a vinyl one on.

IMG_3422 by Rene Cote, on Flickr

[RC_dc2]

looks like this forum only lets me embed one video per post, so the first one is a hyperlink.

Any admins know if this is a user setting that can be changed or is it a global forum thing?

[RC_dc2]

A few updates just in time for the Cup Day sprint

I'd planned for fitting a roll cage for quite a while and I recently got around to getting it done. I opted for a bolt in half cage + harness bar, mainly because it is still a road registered car and I can remove it if needed. It was supplied unpainted as requested, I sprayed it with some VHT Rollbar and Chassis satin black after a bit of a clean up. The plan is to start using a HANS device, a friend had a mild prang coming through dandenong at Sandown and still came out of it with a sore neck. It made me have more of a safety focus.

It's Great work done by Fabraications, once it got dropped off the turn around was really quick. They also managed to get it all done in one piece without any crush joints whilst still be removable and still being extremely tight to the body . I ditched the $5 rear strut bar and got them to incorporate a weld in chromolly bar to the boxed in section for the rear legs. It was nice having something professionally done for a change!



















Obligatory plug....


I replaced both front wheel bearings, hopefully this gets rid of the brake shudder. I couldn't feel any play in the bearings by hand in and didn't have a dial gauge handy. The last measurement I did on rotor runout was when I had slotted rotors and it was impossible to get a reliable reading due to the slots. If this doesn't work then I'm not sure where to go next yet.

Uprights out...


Old dirty bearings vs new NTN. The old ones were koyo, so they could have been the original ones still.




I inspected the front pads after the last trackday, Project Mu RC09 with minimal work since I couldn't lean on them....this doesn't look good but I'll keep them in and check them after the next track day. I'm planning on fitting some ducting in the next couple of days.



I also had this magnaflow muffler lying around for the past couple of years with the intention of putting it on. I finally got around to it once a mate got his welder working. I used 3 mandrel 2.5" bends and flared the end to fit the standard dc2r donut gasket at the axle joint, then slipped a standard flat flange around it. They're not the prettiest welds but the inside is free of any splatter or protrusions and there are no leaks, it sounds fairly deep but honestly not as loud as I thought it would be. The engine noise is already fairly loud with the stripped interior and the hardrace engine mounts, the muffler just adds a bit of depth. We'll see how much my ears are ringing after the next track day.

Mock up shot


Finished and painted, sorry for the blurry iphone pic under the car!






It ended up slightly off where I wanted it but looks ok for a track hack.

That's it for now, thanks for reading. If anyone is heading to Sandown for cup day drop past and say g'day.

[felixR]

Impressive cage work!

[ChargeR]

Fabraications have done nice work, fitment of the roll bar looks great! If you're interested, we have some brake cooling products that would work well in your application: air guides.

[RC_dc2]

Fabraications have done nice work, fitment of the roll bar looks great! If you're interested, we have some brake cooling products that would work well in your application: air guides.

Cheers, I had a look and I'll keep them in mind.

I'd made up some very cheap diy ducts ages ago which I am finally trying, see the next update. One day I might need to upgrade to something slightly more proffessional!

[RC_dc2]

Hey all,

Time for a final update for the year and wrap up from Sandown on Melbourne Cup Day.

I did some final fitting up the night before of some brake ducts. Originally I was planning on just running ducting from the front bar but I found that it was not so easy to route without having nasty bends and compromised intakes. The only decent place I found was if I removed the indicator housings and modified them, being a road car that didn't really suit. I was inspired by some under arm ducts apparently from an older 911, the FWD setup makes it a bit harder to fit around the driveshafts and calipers. Anyway here is my effort.







On the day I still had the same brake shudder problems, I'm not sure if it is just poor bedding in or the pads themselves but they seem to cause the shudder as soon as they get some heat into them. Based on that I don't think it is a hub/runout problem but more of an issue with heat and the pad material adhering to the rotor making high spots. I'll have to revisit this AGAIN, check the runout and if out of spec replace the hubs (the last part that hasn't been replaced) and maybe switch pads again. The ducts may have helped, I didn't end up with a soft pedal at the end of the day. More testing is needed here.

My times were pretty average all day, mostly due to heavy traffic and no blue flags in use. I was getting pretty frustrated and made a semi risky pass coming up to turn 6 which left me out of position and I lost the rear end.

My best time was a 1:31.22, I was hoping for some improvement but it was just not coming together on the day. My optimum lap was 1:29.52 so there is still hope for getting under the 1:30 with this setup.

The last session finished badly being shunted in the rear by a reckless Ford Au driver. The worst part was I talked to him when we came into the paddock and he blamed me for not giving way. I have NFI where he thought I was going to go, I was following the same line the whole day. Anyway, it could have been worse I guess but I would still rather have driven home in one piece. Have a look at the in car footage, it would have been good to have an external view as well but you be the judge!








Here are some pics taken of the day courtesy of Trackside Photography and some video footage of some of the more interesting moments of the day.

The pics really highlight the need for some spring upgrades, loads of dive under brakes and roll on the front!!

[tinkerbell]

Ford probably ran out of brakes... using you to stop running off the road...

and where i drive "the overtaking car has ULTIMATE responsibility for the pass"

this should be discussed at DB?

[RC_dc2]

Ford probably ran out of brakes... using you to stop running off the road...

and where i drive "the overtaking car has ULTIMATE responsibility for the pass"

this should be discussed at DB?

Yep, the ford driver fucked up and wouldn't admit it basically.

In the driver briefing they said EXACLY that, responsibility is with the overtaking car, they also said try to keep the passing to the straights. I mentioned that when I got out of the car, he claimed I pulled over to let him pass but then I swerved into him!? He span out after hitting me and was lucky not to do anything more serious. His car didn't look like it took any damage either lucky for him.

[RC_dc2]

i realised that I messed up the subtitles in the vid, fixed now.

[RC_dc2]

I've been catching up on a few things that have been on the list to fix.

Before that I spent some cash on some safety updates:

My harness expired last year and since the cage install I can now run a HANS device. I chose an OMP HANS specific harness and the sport III model. For some reason the sport III was cheaper than the sport II from rallynuts.




After the cage install I had to clean up under the car where the mounting plates had been welded. It had been a few months but hadn't rusted up much. A quick smear of seam sealer and under body paint fixed it up.





Getting to the welds for the main hoop mounts meant taking out the rear trailing arms. I knew the rear bushes weren't installed in the right orientation when I got the car, these were the only bushes that had been changed before I bought it and I'd been meaning to fix them up for a long time but I just never got around to it. Both sides were different and both wrong, looks like they had just been randomly pressed in. A few taps with the hammer and I had them out and re-installed correctly, this should stiffen up the rear particularly on the drivers side which was 90 deg out so it was probably softer than stock.

Wrong




Fixed


I also fixed up one of the rear damper forks, the thread was stripped when I bought them and I'd been using a random long bolt and nut since installing them. I ground off the old captive nut and welded a new one on. I definitely need more practice on the mig. This yellow was the closest match spray can to Bilstein from bunnings and it got scratched a lot when re installing it. Meh.





Lastly, my old front lip was trashed and being held on with tape as you can see in the track pics from my last outing. I bought a replacement, I'm pretty sure it's the same one I had before that came with the car. It'll be painted at some point at the same time as I fix up the damage from the rear bump I took at Sandown. It's held on with tape in the pic before final fitment.





There's always much more to do, I'm hoping to get out on the track soon and then following that some more upgrades. I'm really hoping to get under the 1:30 at Sandown on this current setup before changing anything else!

[ChargeR]

Nice updates, it's satisfying to get jobs like that out of the way.

I'd consider changing the orientation of the trailing arm bush though. The OEM bush is designed to be compliant in the fore/aft direction but I believe that's part of a deliberate design decision by Honda to introduce compliance steer under brakes for stability. For a track car it might be more beneficial to minimise the fore/aft compliance and have the voids in that urethane bush at the top and bottom so that it will be more flexible as the camber changes.

[RC_dc2]

Nice updates, it's satisfying to get jobs like that out of the way.

I'd consider changing the orientation of the trailing arm bush though. The OEM bush is designed to be compliant in the fore/aft direction but I believe that's part of a deliberate design decision by Honda to introduce compliance steer under brakes for stability. For a track car it might be more beneficial to minimise the fore/aft compliance and have the voids in that urethane bush at the top and bottom so that it will be more flexible as the camber changes.

That's interesting. One side was set as you mentioned and the other was at ~45deg. Maybe the previous owner had it set up for oval track[emoji12]!

They seem fairly compliant with the voids in the vertical plain, it may be better trying a different design to keep constant toe setting. The white line version is solid with no voids, there is a superpro version that is 360 deg symmetrical with voids or hardrace style which might be worth a try. I'll see if I notice any difference how I have it now.

In any case the reward I got for this latest effort was this (through thick nitrile gloves that didn't rip mind you)



And a stuffed lower back. Definitely a sign of getting old. Anyway I'm done crawling under the car for a little while until this latest injury clears up. Motorsport is a dangerous past time!

[ChargeR]

That's interesting. One side was set as you mentioned and the other was at ~45deg. Maybe the previous owner had it set up for oval track[emoji12]!

They seem fairly compliant with the voids in the vertical plain, it may be better trying a different design to keep constant toe setting. The white line version is solid with no voids, there is a superpro version that is 360 deg symmetrical with voids or hardrace style which might be worth a try. I'll see if I notice any difference how I have it now.

Yeah it's interesting, and it was just something to consider. If you run it like it is and you're happy with the handling I wouldn't bother changing it to be honest, even oriented as they are they're probably stiffer fore/aft than the OEM ones. I've never used urethane trailing arm bushes myself, but there's lots of internet hearsay suggesting that they can bind and make for odd handling if care isn't taken.

Also that pic is gross.