Budget DC2 VTi-R Track Car

[Setanta]

I love what you are doing with this. Keep up the journal please

[RC_dc2]

I love what you are doing with this. Keep up the journal please

thanks man, i'll have to remember to post closer to when things actually happen so I can remember it all.

Reading back this thread makes me realise how much time this car sits in the garage in between track days. I may have to rename the thread "budget GARAGE car build" haha.

[Grant@Honed]

Congrats on the new PB, 1:31 is really good!

How committed did you feel you were going over the top?

[RC_dc2]

Congrats on the new PB, 1:31 is really good!

How committed did you feel you were going over the top?

Thanks mate.

I would say not very. I've got some racechrono data to review I may post up a screenshot later.

Basically I was getting to 190km/h before Dandenong then braking down to 140 and cruising around the left sweeper. I was only using light throttle down to turn 9 whereas talking to a friend he is full throttle between the corners with a similar power/weight vehicle.

I really have to get around to installing that diff I bought off you ages ago (teaser for another update!!). I was really struggling to accelerate out of turns 4, 9 and 10 with the open diff. I would think this upgrade alone would bring me close to the 1:30 flat.

The other thing I'm looking at is the 260mm rear brake upgrade. At the moment my fronts are getting way too hot, I'm hoping upgrading the rears coupled with some cooling ducts on the front may help balance things out a bit. I was reading your thread, it didn't sound like you were overly impressed after the rear brake upgrade? Any more thoughts since?

[Toddxxx]

good work man! great times!

[Grant@Honed]

The LSD is said to make a significant difference, will be interesting to see what that translates to in terms of lap time. I suspect at least 1 second if not more

So if your pedal is going soft that points to an issue with your fluid overheating

You could try fitting titanium brake pad shims from hardbrakes ( https://hardbrakes.com/ )

These in theory reduce the heat transfer to the fluid in your caliper

I've fitted a set but yet to run on track with them, it's a cost effective upgrade too

Hard to draw comparisons to my brake set up as I ditched ABS and that caused me untold issues until I ditched the booster as well.

I don't think you'd notice any appreciable increase in outright braking performance going to 260mm rear brakes, might help your brake balance but if you're not having an issue now i wouldn't worry about it.

Keep in mind also that unless you spend the money and get Dc2R rear calipers using prelude or ep3 rear calipers with the bleed nipple in the wrong spot is a pain in the ass.

[RC_dc2]

The LSD is said to make a significant difference, will be interesting to see what that translates to in terms of lap time. I suspect at least 1 second if not more

So if your pedal is going soft that points to an issue with your fluid overheating

You could try fitting titanium brake pad shims from hardbrakes ( https://hardbrakes.com/ )

These in theory reduce the heat transfer to the fluid in your caliper

I've fitted a set but yet to run on track with them, it's a cost effective upgrade too

Hard to draw comparisons to my brake set up as I ditched ABS and that caused me untold issues until I ditched the booster as well.

I don't think you'd notice any appreciable increase in outright braking performance going to 260mm rear brakes, might help your brake balance but if you're not having an issue now i wouldn't worry about it.

Keep in mind also that unless you spend the money and get Dc2R rear calipers using prelude or ep3 rear calipers with the bleed nipple in the wrong spot is a pain in the ass.

Yep, fairly sure the fluid overheating was the cause of the long brake pedal at the end of the day. I haven't really experienced this much even with lower spec fluid but I think this time I was pushing a lot harder (proven by the lap times) and getting more heat into the fronts with more aggressive pads. I didn't have the IR thermometer this time so not sure what the temps actually were. Enough to bake the fresh paint I did on my rims and turn them grey though - lesson learnt, must use high temp paint next time not standard acrylic.

I'll look into those shims, I'd like to see a non biased review so keen to hear back after you've tested them.

With the rear brakes, I'm hoping that upgrading them will lessen the load slightly on the fronts and give a bit better balance. At Winton I measured the temps and with the fronts at 370 odd the tears were down near 100. At the moment after 5 or so track days the tears still look brand new and aren't really doing that much. I do want to avoid the upside down bleeder, I was hoping that another model had the 9clp14s calipers in the right orientation for the dc2 (besides dc2r and ek9 since they are hard to come by).

[RC_dc2]

Update teaser...

I'll just leave this pic here. It's not quite 'overnight parts from japan' but they are heading my way courtesy of Jesse Streeter.

[ChargeR]

Awesome thread mate, it's great to read about your progress on track. 1:31 at Sandown is very brisk for a lightly modded VTiR! Keep the updates coming.

[eskimo_firefighter]

Extremely consistent lap times at Sandown, really well done. Liking the concise updates too!

[RC_dc2]

Awesome thread mate, it's great to read about your progress on track. 1:31 at Sandown is very brisk for a lightly modded VTiR! Keep the updates coming.

Thanks mate, I'll try to keep the updates interesting! Unfortunately I don't think I'll get out to the track again this year but I have a few little upgrades planned to keep me busy.

I was chatting to a bloke with a CRX (ef maybe??) who was posting in the 1:29's with a previous PB 1:28. He was fairly modified chassis and engine wise but said he was still running the d16z. We weren't in the same group but it would have been good to follow him round and see where I can cut some times. His car was weighing down to ~900kg with driver so could be a similar power to weight as mine. I'm hoping to eventually get close to that with some more practise.

Are you in Melbourne?

[ChargeR]

Thanks mate, I'll try to keep the updates interesting! Unfortunately I don't think I'll get out to the track again this year but I have a few little upgrades planned to keep me busy.

I was chatting to a bloke with a CRX (ef maybe??) who was posting in the 1:29's with a previous PB 1:28. He was fairly modified chassis and engine wise but said he was still running the d16z. We weren't in the same group but it would have been good to follow him round and see where I can cut some times. His car was weighing down to ~900kg with driver so could be a similar power to weight as mine. I'm hoping to eventually get close to that with some more practise.

Are you in Melbourne?

Yep I'm in Melbourne. Hopefully see you at a track day soon.

That fellow you were talking to would have been Jason with the yellow EF7 CRX. That's a nicely setup car, and a good time to aim for. He's probably got more power than you expect though, as he's tweaked that D16 quite a bit!

[RC_dc2]

Time for a small update.

I haven't had much time to spend on the car recently, I worked through the Christmas break only having Christmas off and life has just been busy after that. I had been waiting on some rear brakes that I posted a pic of earlier, they came on the slow boat from Japan and ended up here late January. I opened them up and have to say that they were in worse condition than I originally thought.

From the photo's on yahoo what I thought to be just dirt turned out to be a lot of rust, they took a fair few hours of wire brushing, filing and chipping away to get to the bare metal underneath. Luckily the internals were clean and in working condition, all the external bolts and handbrake mechanism needed to be replaced.

Here is how they looked when I got them:







Back to clean bare metal:



This is what I found in one of the brackets, either from internal rust or porosity in the original casting. In either case the hole is quite deep and there is an open cavity inside and it is in the thinnest part of the bracket. I decided not to bother trying to weld it up and just went down to the wreckers and picked up a new bracket from a DC5.




Dissasembled, painted up and ready to put back together:



Finished product:



While I was at the wrecker looking for the brake caliper bracket I found an EK with brackets for a rear strut bar, I had been meaning to make something for the rear for a while so this inspired me. Someone had taken the bar but not the brackets, so for a few bucks I got the brackets, went down to the local steel suppliers and bought a couple of lengths of steel tube. I got square RHS 16mm x 1.6mm and 25mm round in 1.6mm wall thickness. The square section fit the brackets better but wasn't as stiff as the round, the weight differenct was negligible so I went with the round and just formed the ends a bit so the fit the bracket. Overall around $5 total. I also decided to remove the rear trims at this point, I probably wont put them back in and will just finish painting the arches to match the floor pan that I sprayed earlier.





I am still waiting for some 260mm Diameter 4x100 rotors to come in, so installing the calipers is on hold for another week or so until I can get around to it. I bought rebuild seal kits for the front calipers too so they need to be removed and fitted as well.

In the next update I'll be setting up some new tech toys that will make enhance the track day experience, plus who doesn't like gadgets? Stay tuned...

[RC_dc2]

its midyear, time for another small update.

It has been extremely slow progress on the car front, many things are contributing (no time, many commitments and a bit of laziness).

While upgrading the rear brakes in the last update I decided to do a bit of maintenance and checked the fronts. I bought all new OEM rebuild kits, what I found when I took the front pads out was not inspiring (refer back to my earlier post regarding the fade I experienced at Sandown - turns out this wasn't just a fluid problem) .

No pics of this, suffice to say the pads weren't in good shape (Pmu RC09 used for one track day after street bedding). I contacted the local distributor Racer Industries and explained my application and the results and they were very helpful. The result is I have another set of new RC09 pads to try, if these are no good then I will have to upgrade to something even more track focused. There was nothing wrong with the calipers themselves, the seals and boots were all intact and no internal rust found.

In addition to the new pads, I did a lot of research regarding more upgrades to the front brakes. I looked at the available kits but I really want to keep the 15" wheels so going bigger than 282mm diameter is not really an option. There are some wilwood kits that fit under 15's but I am skeptical as to whether this will be any improvement except in the weight department.

So, I decided to keep my current calipers and switch to a 282x28mm rotor as seen on NA1 NSX, some mid 2000's Accords and GS Legend etc. All that this upgrade requires is a new set of 28t caliper brackets and a slight machine on the face to get the correct offset on a 4 stud dc2. The rotors are 4x114.3 so need to be redrilled to 4x100 for a dc2.

I did a bit of internet scrounging and turned up a set of 28t brackets from acuralegend.org and had them shipped over from Florida U.S.A. Enough talk, time for pics....

I was debating rear pad choice. Time will tell whether the HC800's are too much in the rear.





New 28mm thick (left) vs Old 22mm thick (right)


I noted that the RDA7996D (ie '07 Mini Cooper 280mm rotor) I used before is not an ideal setup for brake cooling if you keep the front splash shields in. The ID of the rotor is left as the raw casting and sits very close to the splash shield almost completely blocking airflow to the centre. You can see the new DBA rotor 2514 from an 05 Accord Euro V6 has a bigger ID (dba decided to add some machining processes here) which will allow more air flow through the centre of the rotor. I removed the splash shields before the last track day so this wasn't the issue for me. It would be interesting to see whether the equivalent mini cooper rotor from DBA has the same ID as dba, to me it the DBA look to have more money spent on manufacturing and appear the better product metallurgical aspects aside. I don't have a set of stock honda rotors to compare either.


I was also hoping that the air gap would be bigger on the 28mm thick rotors, turns out it is virtually the same as the 22mm thick rotors. This means more material for heat sink but slower rate of cooling - I'm not sure if this is ideal for short sprints yet or not.


Machined 28t brackets - there was a raised pad at the mounting surface so after milling 2.5mm to centre the rotors it is only ~0.8mm thinner at that point.










I've checked clearance on the stock 15" rims and my track wheels and the 28t bracket is fine. It actually doesn't really sit any further outboard than the 23t bracket.

I've collected a few more bits and pieces too.

A cheap lenovo android 7" tablet, GoPro 4 silver and a Qstarz gps receiver. The tablet fits perfectly in the old stereo position, looks almost factory with a slight DIY feel.




This setup looks really handy and can do a few things
- Connects to Hondata via bluetooth.
- Connects to wireless control of the GoPro I just got (thanks to work from a flybuys style reward scheme!)
- Connects to Qstarz for Racechrono

During track days I think it will be very valuable to monitor lap times and sectors on the go, I will be able to see it flashing green/red without directly looking at it to see if I'm improving lap to lap.

The hondata App I have not found overly useful. It can view DTC's and can view engine sensors, the screen has limited customization and cannot take a recording or view/change parameters. There are other apps which I am hoping to try out, one of them was to be Sdash, however the developer has taken this app down and is no longer supporting it.

I also picked these up for a steal after trying out a friends alpinestars silicon lined gloves. After the sweat builds up the stock wheel is getting pretty slippery, these should stop that problem as well as being FIA rated (fire retardant). I have a steering wheel on the way but I'm having a few boss kit compatibility issues so I am waiting for the new one to come in. Will take some pics when done.



The other thing I am working on is some ducting for the front brakes, I'll detail that in another post. I am looking forward to not having to worry about brakes anymore!

Until next time....

[felixR]

Nice work! Hopefully that resolves the braking issues.