posted on March 28, 2011 20:30
Project S2000 Part 7 - Cold Weather Fun
By Khiem Dinh
Khiem Dinh is an engineer for Honeywell Turbo Technologies at the time of this writing. All statements and opinions expressed by Khiem Dinh are solely those of Khiem Dinh and not reflective of Honeywell Turbo Technologies.
Our previous track day was in the middle of the freakin desert during the heat of summer to see how the cars’ various systems handled the almost 100F temps. The upgrades of the Koyo radiator and StopTech brakes took the heat thrown at them and didn’t even break a sweat, but the stock oil system wasn’t up to the task and probably wished it could have sweated to get rid of some heat. Before the end of last year, I hit up Streets of Willow with Speed Ventures to test out the car's systems in cold weather along with the new chassis bracing. More recently, I did the Speed Ventures brand of auto-x with a dozen co-workers for a friendly intra-work competition, but more on that later. The great thing about cold weather is it helps with durability and reliability. Heat is the enemy of track cars and causes problems such as over heating coolant, oil, tranny fluid, diff fluid, brake fluid, brake pads… you get the idea.
The forecast was for early morning temperatures in the 30Fs with the high being in the mid-60Fs. I figured with the cold temperatures, I’d try a test and run the standard 10w-30 oil weight instead of the 15w-50 I used in the heat of summer. Also, with SOW being a relatively slow track combined with the cold temperatures, I left in the StopTech street brake pads instead of swapping them out for track pads. I did hook up my ghetto brake cooling as I figured more cooling wouldn’t hurt.
The results of my experiment were mixed. The coolant pretty much stayed a constant 89C the entire day aided by the big Koyo radiator. On AP2 S2000s, 89C is the temperature the thermostat maintains for the coolant, so no coolant temperature issues here. As a note, AP1s seem to have a thermostat that maintains a temperature 5C cooler from what I’ve researched.
Do you know how I know the foam strip was doing its job of blocking air? I had to add some tape to keep it in place because it had gotten blown out.
Tuesday, March 29, 2011 4:51 AM
Suggestion for fixing the loosness: VHT and a burnout pit before staging for the autox?
Sorry, I just watched a bunch of drag racing on youtube.
Tuesday, March 29, 2011 7:49 AM
Oil psi is usually has a minimum ratio. I have used 7psi per 1000rpm. I believe that 1.2bar at idle <1000rpm is sufficient.
Tuesday, March 29, 2011 11:31 AM
1.2 bar is certainly not catasphoric, but not too good for this engine. The factory manual calls for the following pressures as measured at the stock oil pressure sender location at an oil temp of 80C: 2.5 bar at idle, 6 bar at 3000 rpms. My car is close to 2.5 bar at 80C being measured at the oil filter. So with normal pressure at 95C-100C being 1.5 bar, 1.2 bar seems a bit low.
Tuesday, March 29, 2011 11:48 AM
That clicking under bump might be your CVs operating outside their articulation range. How do the axles look at ride height? That might also be a source of your looseness, since the binding axle will likely add to your wheel rate.
Tuesday, March 29, 2011 2:42 PM
Out of curiousity, how many miles are on the motor right now?
Tuesday, March 29, 2011 7:12 PM
Steve, I agree the noise was probably the CV joint. On the stock suspension, the right side of the car was ~1/2" lower than the left. The current ride height is the same as stock on the right, and lowered 1/2" on the left to even it out. As for the looseness, it's just the combination of springs, swaybars, and tire width I'm using. It needs a little bit more spring rate up front.
Der Bruce, just about to turn 57k miles. I bought it with just under 37k about two years ago. The engine mounts are pretty good and worn. I'm not too surprised though as the engine mounts on my old SE-R were torn after about 20k miles.
Wednesday, March 30, 2011 9:45 AM
Word. I've had pretty good luck with Swepco 101 Moly grease for getting a couple more degrees out of CVs before binding (25* total) on my off road car. You could always race prep them, but that's likely not worth it for a street car.
Wednesday, March 30, 2011 4:16 PM
Any chance you can give up the specs on Jim's STR winning s2000? :) brand headers, exhaust, coil overs, tire size's, etc :)
Wednesday, March 30, 2011 7:52 PM
@shifterracer, I made a slight mistake. Jim came in 2nd, but was the fastest S2k out there. I was a little off....
Not much in the power department on Jim's car, just a knock-off Mugen intake and a single bullet muffler that replaces the stock dual mufflers saving about 50 lbs. Oh, there are over 200k miles on the engine and the only thing he's done was replace the rod bearings. Wheels are custom widened Enkei's to 10" I think... Hankook RS3 in 255/17. Suspenison is a set of used Penske's that he got rebuilt and I think his spring rates are 850f/700r. For sway bars, I think a 1.75" front bar and stock rear. I'm pretty close on the info, though maybe not exact. Total investment including the price of the car is under $20k. Did I mention the boy can drive?
Thursday, March 31, 2011 9:13 AM
good info spdracerut! I'm still trying to go through 144 pages of posts on another site to see what the preferred setup is! I like KW's stuff so i'm leaning towards those :) Now i just need to figure out the power stuff.
Nice to hear the s2000 can be driven like you stole it and survive for such a long time. My 06 STI only lasted 59k (stock) before it blew up :( Hence why i now have a s2000 for a fun car.
Looking forward to your next report!
Tuesday, April 12, 2011 12:12 PM
shifter, I'm pushing 95k on my AP1 and the only thing I've had to fix on the engine is a coil pack on cylinder #1. I absolutely do NOT drive it like a grandma.
Khiem, still need to drop a small box in the mail for you. :(
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