Hampton Play Day.

[Mad Kiwi]

Well my first track day and wow, what a blast....!!!!!


A quick run down for posperity sake. Someone may find it interesting.....

The HSD suspension seemed to do what it was meant to do...Started out with some serious mid corner, just transitioning from off to on throttle oversteer. So I slowly stiffened up the suspension but more towards the rear and that settled the car down quite well.

A spin on my 3rd ever lap in the "s" section was a quick "ahhhm, your pushing a bit hard for a newbie here fella, you might want to back it off a bit for awhile" series of thoughts...but the suspension tuning did help that corner significantly.

Bad news was I must have overheated the front pads as they effectively disapeared on my second to last lap and ended up steel on steel....considering they were at least 2/3 full when i started that wasn't a good sign....also went from full to nearly empty on the brake fluid so need to figure out a solution to that...

Was a long, slow, grinding drive back to the Shore from Hampton Downs with marginal brakes, thats for sure.

Toyo TR1s went very well, first session they were only slightly tacky and I thought, man these tyres are pretty hard, what is everyone raving about. The second session on they heated up and got very sticky...seems like they will last quite well. Better tyres are on the cards but only after I improve the driver for awhile....

So I ran a few 1.27's while babying the brakes quite a lot (pedal got spongy very quickly...should have freshened up the fluid as was suggested )

I am quite pleased with that time as the "slow" group cutoff was 1.25 or higher....

I did see a rise in water temp on the session that I was revving it all the way out which was a worry but the next session I dropped 500 rpm off the rev limit and it didn't do it.....is this normal??? ( I WAS caning it pretty hard....)

I think I could easily drop 1-2 seconds off with a bit more practice and then 1-2 again with better brakes and the limited slip diff thats coming!!!

I think I got to about 75% stiff on the shocks so will probably crank that up a bit more to speed the off to on throttle weight transitions and help maintain atitude mid corner a bit better.....

Anyway great fun!!

[Angreal]

Never done it in a car, only on a bike but I did overheat my brakes down the second straight every time.

Best corner is the sweeping right before the main straight although I am gutted I never got my knee down there That has got to be the most ideal knee down corner around.

[m4vr1k]

Regards the heating, I have the same issue in my car, if i shift at 7000, the water temp is fine, if I push out that extra 500, it creeps up.
Cant wait to get out to Hampton for a track day, all I've done so far is Pukekohe

[Skilfil]

Is it in my head or does shifting at 6500 seem to be quicker? Feels like the car isn't really gaining anything from revving right out to 7000. (1.6)

Also, are you guys talking 1.6 or 1.8?

[Mad Kiwi]

Hi Sklifil

I am not sure about M4vrik but mine is a 89 NA 1600and has a turbo fitted. Also quite a large aluminium radiator so the temp thing is a bit of a surprise.

I wonder if it could be oil temp getting high that is causing the heat rise issue?

I was seriously concerned about maybe a head gasket etc but simply dropping the 500 odd revs brought it back to the normal spot within about 1-2 laps and then it stayed locked in there the next session....so hopefully not...

Can the other trackday / racers onboard offer any suggestions?

As far as revving it out, mine was pulling nicely up there and it was quicker to leave it in the gear between a couple of the corners than change up and straight back down again.

Which reminds me the stock 1600 diff ratio in the car seemed a good match for Hampton at those times, changed to 5th immediately after the bump heading up hill on the straight and holding 4th in to the last sweeper was about perfect. Holding in 3rd to the downhill off camber and then hooking in to second seemed spot on as well. Thought the extra revs IS what heated things up...

Hopefully the different LSD diff ratio won't screw that up, or the extra traction will also match the new ratio.........

Also, having done hundreds and hundreds of laps on bikes etc around Pukekohe (which has a strange appeal of its own once you get in the groove) I have to say at this stage I prefer Hampton Downs. For the elevation changes, the off camber corners, the cool and flowing 'S' section, the long sweeper...much more challenging/enjoyable....to me at least...

[m4vr1k]

Mine is a stock 1.6. With the stock timing, I got no benefit from going right up to 7500, but with the timing advanced 4, I get decent power all the way through, with only a small drop off around 7200.
Could it be the water pump cavitating at high revs? I know the SR series Nissan motors have that issue at higher RPM, the water pump just churns up the water, rather than actually pumping it

[Euen]

A couple of points. If you are running a turbo with a standard 1.6 diff you could probably get away with going to a higher ratio. Std 1.6 is 4.3 from memory and you could probably get away with a 3.9 with the the turbo. You would need to go to a later diff (bigger, stronger) though. This would allow you to get a bit more speed at lower revs.

Another option would be a coolant reroute. This allows the coolant flow through the engine from back to front instead of front to front. The standard configuration allows a heat build up at the back of the head as it doesn't get the same coolant flow as the front.

As an aside, I thought most of the early 1.6s had a viscous LSD as standard. (mine does). They weren't particulaly strong but did make a difference.

[punkoutnz]

Yeah Zac I was just thinking about the cavitating water pump thing. There's no room for an over sized water pump pulley though so the only thing you could do is go under sized crank pulley. Is there any such thing available for the B6 engine?

I know in my SR20VE the under drive pulley sorted my over heating issues when driving it in the 8000+rpm range for any length of time.

[Euen]

Underdrive pulleys are available but are not recommended due to the adverse harmonics that can be generated when you remove the harmonic damper.

[Growler]

As an aside, I thought most of the early 1.6s had a viscous LSD as standard. (mine does). They weren't particulaly strong but did make a difference.

As I understand it the imports did but the NZ cars didn't...

[Kieran]

Is it in my head or does shifting at 6500 seem to be quicker? Feels like the car isn't really gaining anything from revving right out to 7000. (1.6)

Also, are you guys talking 1.6 or 1.8?

Its because you want to keep your revs between your peak torque rpm and your peak power rpm
Ive attached a dyno for a stock 1.6 and by looking at that i would keep the revs above 4 and shift at 6.5 after 6.5 the power and torque drop off quick

[Skilfil]

Ah right, I live out on country roads so sometimes get the opportunity to test it out. It certainly seemed to hit 100 quicker shifting at 6500. Good to see some proof.

[Kieran]

Yeah I have a 1.8 6 speed so my torque band is a little different but i find i like to keep my rpm above 3K and shift at 6K for the best acceleration anything above 6K is pointless unless you have a free flow exhaust, good intake and higher duration cams but usually the stock head cant flow enough air at that high rpm anyway so unless you have a built motor dont bother redlining any gear its not helping you just use the gears.

[RMS]

In theory you want to shift at whatever point is going to maximise the area under the horsepower graph. In the graph above that would be at the redline.

Having said that, I agree that short shifting has little impact on the fun and quite a big impact on temperatures so it's not a bad compromise.