Budget DC2 VTi-R Track Car

[plAythiNG]

thanks mate. yeah i might need 2 x 90deg fittings by the looks of it

[RC_dc2]

VSSC Round 6

Bit of a wrap up after the last track day.

Oil Cooler
Seems pretty solid. Peak temps are maybe 5-10 deg lower than before but this is hard to quantify without back to back data with same ambient conditions and lap times etc. On the first session they maxed <110deg, second session was raining so wasn't pushing it as much the temps were at or below 90 from memory. The last couple of sessions when I was really pushing it I was seeing max around 120-125 deg.

The main difference I found so far is that on a cool down the temps are rapidly dropping to around 100 or even lower whereas with the old cooler a cool down lap only brought the temps down to 115-120 and as soon as I started pushing hard again the temps would jump straight back to 125-130. After each session by the time I parked the car back in the paddock they were back below 100 deg usually. Its clear that on the track with the revs in the high range and the high oil flow rate the efficiency of the cooler drops off a lot, on the street the temps sit at 80 deg with normal driving so pretty consistent with the stock heat exchanger maintaining the water temp at about 82 deg. I made a spreadsheet based on the Mocal published data prior to choosing the 34 row, you have to pick individual road speed and rpm points to evaluate so I just worked around average speeds/rpm for a lap (these were really guesses since I don't have datalogs to calculate actual averages).



Lap times
Not up to my best, for the first few sessions they were either in traffic or wet. Also SAU who were running the event were only doing 8 minute sessions so I found it hard to get into the swing of it and nail a good lap before the session ended. It seemed like I was always just about to start a clear lap when the checkered flag came out. I had tried to nail it in the last couple of sessions late in the day but still came up short, I punched out a bunch of 1:31's in the last session which was basically clear for me but no PB's. Best time of the day was a 1:30.99.

34 Rene Cote 1:50.6864 1:39.7067 1:35.7074 1:33.4199 2:10.5979 2:00.7591 1:59.9713 1:54.3974 1:52.0824 1:39.9872
10 1:34.2521 1:36.7924 1:42.6703 1:43.8373 1:39.0068 1:34.5093 1:36.8410 1:33.9907 1:43.0649 1:33.3240
20 1:30.9913 1:31.4550 1:32.1190 1:43.3799 1:31.8071 1:31.4545 1:31.0623 1:37.8113 1:42.3892 9:34.4505p
30 1:43.0460 1:31.9346 1:31.7827 1:32.4467 1:31.4552 1:31.6441 1:37.4159 1:31.1248


After the later sessions I was seeing a bit of pad material collecting on my front rims. Brakes still felt ok, I never ran out of pedal and only mild pulsations when they were getting really hot. At home I checked them out, they seem to be holding up pretty well compared to the PMu RCO9 which I am happy about. They have definitely seen some high temps, the rotors are show the beginning of heat stress on the outer face but no actual cracks yet. Pad material has only worn down about 1mm max, higher wear on the outer pad towards the OD of the rotor which is copping most of the abuse. There is a fair bit of material being trapped in the pad groove and then being deposited on the rotor surface, I think switching back to slotted rotors would help with this.




Next plans...

I have finally become annoyed enough with the lack of traction on corner exits to strip the gearbox out and install the factory ITR helical diff. It actually is not that big of a pain to remove and strip and it should have been done sooner. I am attempting to use the standard taper roller bearings that came on the diff (this one must have been from a pre face lift JDM model) since they are in perfect condition and have better load capacity than the later radial bearings anyway. I checked the drag torque of the original open diff bearings by 2 methods, one was using a click type torque screw driver that measures 0.2-4Nm in 0.2Nm increments and I verified this by hanging a weight off a lever attached to the intermediate shaft. The torque driver method gave me 0.8Nm and the weight method gave me 0.9Nm, that's pretty close! The manual calls for a new spec of 2.5Nm, usually most makes will give you a spec for a used bearing of around 0.7-1Nm as per my old diff, the Honda manual just says reset to 2.5Nm.

Using my existing shims gave me a torque of 3.4Nm and it seems very hard to turn by hand, I am going to set mine somewhere between my original diff and the new spec. I've ordered some new shims and taken a bit of an estimate on what thickness I need, unfortunately I thought these were coming from Australia but after ordering I found out that Amayama had to order them from Japan anyway. I'm hoping these get here in time to make it to VSSC round 7 on cup day!

One surprise I found was when trying to torque up the left hand thread bolts on the diff gear is that my Micrometer style torque wrench does not measure torque in an anti-clockwise direction. After a bit of google research i turns out that not many do unless they specifically say Bi-directional even though the ratcheting heads work in both directions. After potentially ruining my torque wrench at the low end of its scale I ended up stretching some bolts on the trans case when checking the bearing drag torque. As it turns out the bolts will stretch well before any damage occurs to the aluminium threads in the case. I solved the left handed thread bolt conundrum by going real old school, I found an old beam type wrench on gumtree for $20 which did the trick nicely.



Here is the result of a bolt pushed too far next to an original length bolt, this happened very easily using a large 1/2" torque wrench, they gave way with very little effort.

Untitled

The gearbox internals seem in pretty good condition for the kms, I haven't stripped out the synchros but the gaps look pretty good and gears don't show any pitting. The case surfaces have a bit of a scummy build up and normal material collected on the magnet. Reverse gear shows a bit of burring, the hard shift into reverse seems pretty common for manual Honda's.













So, now I am sitting around waiting for my parts delivery before I can get this car ready for the next and probably last event for the year.

Lastly a few pics from the day courtesy of Trackside Action Photography and myself.

[RC_dc2]

I got bored waiting for my parts to arrive to reassemble the transmission. My OCD was getting to me on the calipers so I gave them a clean up and they look much better now. I used VHT caliper paint rated at 900*F (482* C) this time instead of Duplicolor which is only rated to 500*F. We'll see if that lasts a bit longer this time, maybe if I don't bash the wheels on the calipers when changing it would help.


I was initially only going to do the caliper body but then it made the brackets look shite so I had to do them as well.



My parts arrived from Amayama just in time to get this thing back together before Cup Day. On a side note - I ordered the shims i needed from Aus stock only to find it had to come from Japan anyway. I used express ship....then the other parts I ordered separately from Japan using standard shipping turned up earlier than the "express" parts which was a bit annoying. A few nights in the garage had it back together and in the car.



This is how I setup to take the diff bearing preload torque spec - threaded rod through the centre with washers and nuts on both ends. This only works for LSD setup since the pinion shaft blocks the spline hole in an open diff, I used the intermediate shaft to measure off when checking my original diff bearing. I chose three shims to order and ended up using the thickest one to get a preload torque of 1-1.1Nm which I am happy with. The middle shim gave me 0.7Nm which I thought may end up too loose after bedding in a bit more given that they look fairly new.



Finished reassembly....




I did manage to re-fit the trans myself on the garage floor which was not as bad as I thought. It probably would be a little easier and quicker with 2 people but there really was not much more room for an extra set of hands under there anyway.

Installed...


I ran it while up on jacks to check for leaking and noises etc before driving it. There was a clicking noise from the drivers outer joint area, I left the outer joint connected to the hub while the box was out so nothing should really have changed here. I think it was just a high spot on the rotor knocking the pad back each wheel rotation. There were no leaks and shifts felt good so I took it for a drive. It all seems to be in order and I couldn't feel any clicking or knocking from the drivers side while on the road.

There is no real difference on the street that I could tell with the new diff. I did give it a couple of firm launches around slow speed corners and I got a bit of a shuffle from the front and ended up turning closer to the inside of the corners than I intended - that could just be me over compensating for expected understeer. Since it all seems to be working I've entered for VSSC round 7 sprint on cup day and I'll see whether this has made any difference on the track.

[Kingk22]

I got bored waiting for my parts to arrive to reassemble the transmission. My OCD was getting to me on the calipers so I gave them a clean up and they look much better now. I used VHT caliper paint rated at 900*F (482* C) this time instead of Duplicolor which is only rated to 500*F. We'll see if that lasts a bit longer this time, maybe if I don't bash the wheels on the calipers when changing it would help.

I was initially only going to do the caliper body but then it made the brackets look shite so I had to do them as well.



-snip-

Where'd you get the VHT caliper paint from? I want to paint my calipers and valve cover but I was looking at Duplicolor from Supercheap.

[RC_dc2]

Where'd you get the VHT caliper paint from? I want to paint my calipers and valve cover but I was looking at Duplicolor from Supercheap.

Autobahn stock vht

[RC_dc2]

Cup Day Sprint

The night before I got word from a mate that he had the corner weight scales borrowed from his club again.

First off, the left balance and cross weight was pretty good without the driver. Rear weight is as expected for a FWD, not much can be done about that without physically removing weight from the front or adding to the rear. Compared to the last time i had the car on the scales I've added the half cage, added heavier brake rotors and diff and removed the sunroof to be around 15kg heavier, not too bad. Fuel load this time was around 30lt, last time I wasn't exactly sure but going by the gauge it was similar, maybe 1/2-2/3 tank.



With driver gets a little worse on the left distribution.



Trying to improve this went around in circles making it a bit worse then better. It's pretty hard to keep the heights fairly consistent and get the balance close across the front axle. I only had about an hour of adjusting time so I finally settled on this before it got any worse. The power was disconnected to the scales at some point and I didn't notice until after that they needed to be re-zeroed. Ignore the total weight here it somehow gained an extra 72kg.



The Cup Day Sprint was VSSC round 7, sessions were long at 20 mins with around 20 cars per group. Traffic was fairly heavy and I was mixed in with cars lapping quite a bit slower. My lap times throughout the day show I wasn't really able to get a clear run until the end of the day when half the field had gone home.



A new PB of 1:29.35, pretty stoked about that but at the same time I didn't feel that lap was anywhere near perfect still so I'm sure there is more to gain. The LSD helped in dropping the times being able to get on the throttle a little earlier and reducing power on understeer a bit. Traction is still an issue on corner exit, the tyres are getting pretty loose now and I'm sliding around mid corner and going deep under brakes with ABS kicking in more often so new rubber would help a lot. The improvements have mainly come from changing down to 2nd for turn 2-4 and carrying more speed through turns 6-7 (around 10kph higher now). There's still a bit more to gain there if I'm game enough.



Unfortunately I was having wifi issues with the gopro again and couldn't reach it to turn it on for the last session so didn't get any footage of my laps in the 1:29's. I've posted a video of some of my earlier laps that were around the 1:31's anyway, I was making a few mistakes as well as coming up behind other cars.

Here's a few pics from the day from Trackside Action Photography again on FB.







I've got no major plans over summer for the car, next season will be more of the same with a few tweaks here and there and work on my driving a bit more.

[iwearmoccos]

Keep on working at it and you're dropping more time, good work!

You should come down to Bryant Park on the 2nd December for some hill climb!!

[RC_dc2]

Keep on working at it and you're dropping more time, good work!

You should come down to Bryant Park on the 2nd December for some hill climb!!

Cheers mate.

I’d love to get more time in the car but December is pretty much out for me.

[Alex_Walker]

Been watching your videos, keen as to get my Integra over to Victoria and hit up some track days!
Cars coming along great, good stuff!


Sent from my iPhone using Tapatalk

[RC_dc2]

Long time no update....

Been busy moving house and not doing much on the car for the first part of the year. Here's a few things that have been done:

New wheels - 6UL's with 225/45R15 NT01's. Tyres are used, maybe a little better condition than my 205's. Managed a new PB 1:29.16 at Sandown back in June with no other changes to the car.

Racechrono says there's 1:27.86 optimal so I'll keep trying at that.

Brakes were starting to look a bit frazzled, pads were actually ok after this event still but the cracks in the rotors are starting to open up a bit. The rotors seem to be getting much hotter on the outer half of the radius on the outer friction surface, I'm not sure if this is due to the modified brackets something else, both sides are the same.





I saw some fn2r calipers for sale on ozhonda FB so got them and some new DBA4000 300mm rotors.

New vs Old


They're a tight fit in the rims, I had to move the wheel balance weights a bit further inboard to clear.





I'm using dtc-60 pads again on the new setup. The fn2r (same as audm dc5r/ep3r) caliper is smaller and lighter than the dc2r. The have a smaller piston and pad but the rotor goes up to 300mm diameter so overall they may not be that different in brake torque for a given line pressure. The fn2r setup has a weight advantage 11.7kg vs 13.2kg for the rotors/pads/caliper combined, pedal feel maybe change slightly but its hard to tell without back to back driving (it's been a while since I drove it last!)

It will be hitting the track again soon.

Random shot from last trackday to finish off.....