Budget DC2 VTi-R Track Car

[RC_dc2]

Philip Island June 2014

The day went ok, I was happy with the way the engine handled the day. I only managed 3 sessions out on the track, the first engine proper run in and making sure it all held together (only managed a few hundred km's run in prior)!!!

The second I pushed a bit harder and focused more on actually learning the track than keeping an eye on the oil temps and pressure. At midday the karts went out and some poor bloke came off a bit badly, there was a hold up while the paramedics checked him out. He was ok which was good, but we lost a lot of time.

After that it started raining so everyone was driving super slow and clogging up the track. So, it wasn't conducive to fast lap times in the end I think 2:03 was my PB. Nothing flash, I'm sure this will be easily improved.

Ambient temps were only about 14 deg C, max oil temps around 120 deg. No drops in oil pressure, kept checking fluid levels between sessions and no measurable consumption!

I got to weigh the car on the scales at scrutineering, full tank without driver 1124kg. This is basically stock interior except rear seats, boot carpet and parcel shelf removed. Need to work on that a bit for next time.

I didn't have any photo's from this day, but I got to use the new gear I got for my Birthday...


Also I swapped the muffler before the day, found this at a wrecker for $30 so thought it was worth a shot. It is an X-Force straight through 2" welded to a stock dc2 axle back piping.


Result was as expected, the hole in the piping in the pic must have blown out during the day. I wasn't overly impressed so I put the stock one back on for now until something better came along.

[RC_dc2]

Went through some weight reductions after Philip Island....

I have to say that removing the sound deadening is one of the least fun jobs going around. The rear half I did with just a chisel and hammer, then mopped all the residue up with kerosene. This way is extremely messy, once the kerosene goes on then it turns into a filthy brown sticky sludge, many many rags were used to get it all clean. The front half I did with dry ice, it was a little easier but not as easy as I thought it would be reading other reviews on the net. Some came up in big sheets but a lot was just frozen little pieces, particularly anywhere near seam sealer was crap to remove.

Rear Sound Deadening Removed


Painted


Front Before...


Cleaned up.


Painted


All up removed
A/C Evaporator 2.06 kg
Rear Sound Deadening (up to rear seat) 3.3kg
Antenna Assy (was broken so just dead weight) 0.86 kg
Rear Speakers 2.32 kg

Didn't weigh items below individually
Front Sound Deadening
Front / centre console & gear stick surround
Radio
Front Speakers
Total 20kg even.

All up weight reductions 28.5 kg. Apart from the weight reduction it is much cleaner and gives you that authentic 'race car' feel, that has to be worth something at least!

I've kept the rear trims in so far, they will probably go later when I get a cage put in. Other plans are the sunroof, there is fair bit of weight in that up high but haven't got around to that yet.

I added some more upgrades that I'd been planning for a while too.

New rear ARB setup. AUDM 22mm bar with ASR brace.


Had been looking for a new exhaust, found a full system headers to muffler from a Au type R. Would have like the Jap one, but this one came up cheap so went with it. It had some very bad restrictions in the header and the B-pipe which I got rid of to improve flow a bit.

Pic below of the overall layout I used ditching the pathetic AUDM cat converter and using a magnaflow 200cel 2.25". I also cut out the flange after the cat, it tapered down to about 47mm OD so I used a section of 57mm tube I had. The whole system now has a constant 57mm diameter all the way from the header collector merge down to the rear axle where the stock axle back is 54mm OD. The ports on the header primaries were cleaned up with a die grinder, the welding of the tube to the flange protruded right into the tube by about 2mm, very average.



Outlet of the header was 40mm ID (not my pic but AUDM header on the left compared to JDM)


Modified the secondary to fit up to the 57mm tube


Finished header


Removed flange reduction


Fitted up


The results....much freer revving, sounds not much different since I am still using the stock muffler except at WOT there is a bit of rasping sound which I think is due to the modification of the header and cutting open the dual wall section which is now left open at the end. I checked over for leaks and couldn't feel anything, i did regret using a 2 bolt flange instead of three bolt though. Top end has definitely pickup up a bit, reaching redline quicker than before. The first time out on the track with this exhaust I noticed I was hitting the limiter a few times whereas before it seemed I had more time before shifting. There is probably a few kw's to gain by swapping the header for something better, I'll keep that in mind if I get the urge for more power. Bang for buck though this swap feels worth it, maybe not if using the stock cat converter.

[iamtonee]

Wow enjoying this thread, take this thing to winton!

[RC_dc2]

Wow enjoying this thread, take this thing to winton!

Cheers.

Have taken to Winton once, just after I did that exhaust swap. Will put in some more updates to bring it up to date soon.

I'm trying to get to Sandown cup day if I can get new rotors in time and get my entry in!!

[Apu]

Nice paintwork on the interior - did you spray? What did you use?

[RC_dc2]

Nice paintwork on the interior - did you spray? What did you use?

Thanks.

I just used white knight brand acrylic spray cans from Bunnings with a clear coat on top. It's supposed to be for touch up on steel colorbond roofing.

It came out a bit more green tinged than the Gray I was looking for but it looks ok.

[Apu]

Well...you put in more effort than me! I just brush painted...and part of it was matt, and part of it in gloss!

[RC_dc2]

Well...you put in more effort than me! I just brush painted...and part of it was matt, and part of it in gloss!

Out of the whole process the actual spray painting was the easiest and most satisfying part.

How did the brush finish come up?

[Apu]

It came up looking like a brush finish would, haha! Looks OK from a distance but once you look down, it's obvious in parts. I wouldn't use a gloss finish if I were to brush paint anything again...a matt finish hides the brush strokes better.

That said, the only prep I did was to wipe it with wax and grease remover. It's a track car...not a show car!

[RC_dc2]

Small update....

After all the weight reductions etc, swapping exhaust and adding the rear ARB and brace I caught up with a friend who borrowed a set of scales from his car club. Unfortunately there was no corner weighting to be done since I don't have adjustable coilovers but it was still interesting to get a baseline. These results are with around 1/2-2/3 tank of fuel, wish I knew more accurately but my fuel gauge is next to useless. I can only tell if it is full or empty, it sits down near empty after maybe 1/3 tank is used and the fuel light doesn't seem to come on at all or I'm not game enough to push it until it does!! Can anyone else with a DC2 confirm when your fuel light comes on???

First setup is without driver...


Next with driver....(there may be some driver weight reduction required!)


Front Left/Right distribution is pretty good, but it is obviously very front heavy as you already could have guessed. The rear left/right is a bit off, the muffler and exhaust is offset but I would not have thought it would make that much difference. Probably that in combination with poorly matched spring rates.

Would like to get it down close to 1000kg (excluding fuel) but a cage is planned later and that will put it up a bit. I want to at least keep the dash in, maybe the door trims as well since I'm not that hard core and it is still road registered.

[Apu]

Mmm...will be interesting to see what mine weighs!

[tinkerbell]

delete sunroof = minus ~15kg + lower CG

delete power antenna = minus 1.5ish too...

looking good

i get 45l into my tank after about 50km on the fuel light, but i have a 1.5l surge tank installed, so main tank gets pretty empty...

[RC_dc2]

delete sunroof = minus ~15kg + lower CG

delete power antenna = minus 1.5ish too...

looking good

i get 45l into my tank after about 50km on the fuel light, but i have a 1.5l surge tank installed, so main tank gets pretty empty...

I'll have to test this tank to see how much I'm filling up to see if my light should have been on. It's been so long in between fills I can't remember when and how much I've been putting in. I haven't really spent much time investigating it but it would be nice if it worked. Maybe a replacement fuel sender should go on the list of things to do (that list just keeps getting longer not shorter).

With the sunroof, I saw a thread you did on ozhonda and eventually I'll get onto that. There was also a pretty good looking carbon fibre plug that itsu-San on here did which I like too. I already threw out the power antenna a while ago, it didn't work anyway grinding every time I turned the car on.

[RC_dc2]

Updates...

I had been looking at upgrading the cams and found a set of OEM type r cams from a local for $100, they sat around for about 6 months till I finally got the time to put them in. Part of the reason for waiting was that I wanted to keep an eye on the AFR's and adjust them if needed, so in keeping with this goal I snapped up a Hondata S300 off a guy in NSW who's build never went ahead (so brand new at greatly reduced price) and installed an AEM Wideband to go with it.





No pics of the cams (they look like standard cams so not very exciting) but I took a pic of the install method. I swapped the valve springs for a set of Skunk2 Tuner Series and decided to use the rope method due to not having a compressor and also this way I could install after hours without annoying the neighbours. It went pretty well, I think it would be a bit slower than using a compressor but this way is still very simple. The Euro Export valve compressor tool came in handy too.



I used a P72 base tune and found that it was very rich all over the map. After a bit of messing around and tuning idle and low speed on some back roads it was running pretty good. I had to wait a while to do WOT runs to find a good place to test, so far I have only adjusted the fueling, timing adjustments will have to wait for a dyno tune.



You can see some pretty bad shifting of the AFR in the first trace, this was after a bit of work too. I found that the IAB's weren't activating and so wasn't able to easily tune it out. Later on I tested the IAB output on the ECU and with the solenoid unplugged 12v was toggling as expected, however something was pulling the voltage down when I tried to activate via Smanager. After a lot of stuffing about I ended up wiring the IAB to a spare output (A/C Clutch) and used a relay with the signal inverted in Smanager. This worked fine and after another tune AFR's looked much steadier throughout the rev range.



This is how I left it for the moment. At WOT the AFR's start in the mid 13's and richen up slightly at redline around 13. Some fine tuning is needed in the future but for now it drives pretty well, there are no flat spots and part throttle feels like it did with the factory P72 untuned.

[RC_dc2]

Budget DC2 VTi-R Track Car

Earlier this year I drove the car up to Winton for a practice day. The car went ok, but in the first session I backed off too much between turn 3 and 4 and ended up spinning off the track.

This was the first time I drove with the upgraded rear ARB, but the reason for going off the track was probably more driver error than anything. The ripple strips are brutal there and I slid off pretty hard and ended up popping a bead off the front passenger tire. After getting towed back to the pits I tried my luck reseating the bead using a small 12v compressor borrowed by some other drivers, to my surprise it popped straight back on and held pressure perfectly the rest of the day. After that effort I didn't really push that hard, no idea of times since my borrowed racechrono didn't wan't to work properly.

Nothing else much to report, it started raining in the afternoon so I had to really back off. Only one pic of the day....



After doing an inspection a few weeks later I found my front pads had disintegrated, so no more EBC Yellows!!! I didn't notice them dropping off too badly on the day, maybe if it didn't rain I would have found out sooner!



For reference I measured the temperature of the rotor and caliper with an IR thermometer in the pits and had a highest reading of 374 deg C.

Fast forward a few months and it was finally time for another track day. After lots of sitting around in the garage and a few weekend drives I was pretty keen to get out there. I'd done a few upgrades prior to heading out.

New DC2R wing, originally milano red.


Then hit with the torino red spray can


New battery, old one died after sitting so long not being used. 7kg vs 12kg


The best update....


I sat in so many different seats and this was the most comfortable. The velo podium II was good too and the Sparco Pro2000. Most were too narrow for me both hips and shoulders, I'm glad I didn't order over the internet I would have been dissapointed I think. Ideally the Racetech RT4009 would have been my first choice but it was literally more than twice the price so I just couldn't justify it. This one suits my needs and is FIA approved. It also allowed me to add in the crotch strap to make a 6 point harness. I bought mount kits from revolution racegear, they have very sharp corners so had to clean them up on the grinder first (original is on the right, radius-ed corners on the left)


Now they meet CAMS spec.

I added a heel plate for a flat surface, also the painted floor is pretty slippery and getting in and out of that seat is tricky.



With all the carpets and firewall mat removed the throttle plate is fully open with about 25mm before the pedal hits the floor. This was stretching the cable and stressing the pedal mount when mashing it hard during tracking. The night before I riveted a piece of aluminium to the back of the pedal. This was just a quick fix, I may change this to something mounted on the floor later. I've had a pedal mount snap off the firewall before and it wasn't fun.



New brakes




All flushed with 0.5-1L of PBR 600 brake fluid (600deg F). Naturally the final parts to do the brakes only came in 2 days before Sandown on Melbourne Cup day, I did a quick bed in of the pads/rotors on the street but only up to about 80km/hr. They felt pretty good no issues so off I drove to Sandown on Tuesday.

It was a long time in between visiting Sandown, around 12 months so I really couldn't remember my lines or braking points. The first session I was really disappointed with my brakes, for some reason pretty much as soon as I jumped on them the steering wheel wanted to jump out of my hands with really bad pulsating only evident while braking, so not wheel balance or bearings/cv joints. I came back in and checked everything over, nothing loose, wheel turning freely very slight tight spot when the pads were dragging.

I decided to disable ABS and see if that had anything to do with it, the next 2 sessions the pulsating progressively went away until it was unnoticeable. I re-enabled ABS and found no more issues, in fact I kept braking too early and ended up just cruising up to the corners. These pads are pretty awesome, I stomped on them as hard as I dared and they never seemed to fade. What I did note was that my suspension is not up to the task and this was the limiting factor, the car was feeling fairly unsettled under brakes particularly coming up to turn 1 I couldn't setup properly for the corner with the front diving and squirming all over. The toe out at the front and 3.5deg camber may not be helping here.

By the last session of the day I was pushing fairly hard, oil temps were starting to creep above 130 deg C (something needs to be done here) in the 12 min sessions - around 6 laps. The brake pedal was getting long too, most noticeable again braking for turn 1. Even with the longer stroke the pads were still biting hard and I never felt I was going to go off the end of the track. I was just about to start doing cool downs when the checkered flag was being waved each time.

So the results....

Previous PB last year 1:36.03

this time around.........

1:31.48!!!!!!

This was the timing from Natsoft, due to the delay in them posting and me reviewing I really was surprised at the times. I still felt like so many mistakes were being made and areas to improve. Consistent improvement was being made throughout the day, especially once the brakes smoothed out. Looking at the last session the times were fairly consistent, out of 8 laps 5 were in the 1:31's.




In any case I'm pretty happy with the progress and hoping to drop under 1:30 soon.