Peters NA6 "Britney"

[PeterB]

A great day at the State round on 30 July, resulting in my personal best in this car of 1.14.81.

This was my target when I put the car together, so I am very pleased, but now need to get more track time to get the best from it. Comparing notes with Bryan after his excellent 1.14.9 in his stocker is a good incentive to get cracking.

The Torsen was definitely an improvement, with no wheelspin and better drive out of the fishook. However, I left a trail of diff oil so the drive shafts need to come out and new side seals fitted.

My (and Bryan's) experience show you can expect 1.5 to 2 seconds a lap improvement from semi-slicks over performance road tyres (in my case I have improved 1.5 seconds over my best on Kumho KU36s).

I think the next most significant improvement was the Torsen lsd (will be of greater benefit at the hillclimb).

So my improvement list for tracking an NA would be :

Ensure safety equipment is up to scratch - say Roll over protection (BD or similar) and maybe install a race seat and harness if so inclined.

1. wheel alignment and ensure bushes are ok
2. brake pads (eg Hawk HP+)
3. best tyres for your class

Then lots of track time until you are getting the best from the car, then go for

4. lsd
5. shock absorbers (adjustable if suitable for class)
6. swaybars (preferaby adjustable)
7. springs
8. underbody bracing

then go looking for horsepower, aero, etc as your class allows.

I will run mine on the dyno for interest to see if the pod filter is giving real benefit, or if the exhaust is limiting its potential. I certainly wasn't driving away from Bryan on power, but if he is carrying more corner speed, that is worth quite a few horsepower.

Off to the Fairbairn hillclimb in a couple of weeks to see how the diff works there.

[Guran]

Nice work Peter! It was a lot of fun trying to keep up with you on Saturday.

What are your plans for the club trackdays this season? Staying in modified NA6? Or maybe fitting some "road tyres" and trying Clubman class? I haven't counted your list of mods but it might be close to Clubman specs.

Edit: I think I count six mods in your list (plus the R888s), and cleaning up the ports is not allowed either, so it's probably a bit late for Clubman class.

[PeterB]

I am considering going back to clubman later on as I could easily remove a few things without real detriment to performance and make it more streetable (the shocks/springs are a bit stiff for the road). I was happy with the Koni yellow shocks and stock springs on my previous NA.

The cleaned up ports on the head is the real stopping point as I would have to refit a standard head. I was thinking of doing this anyway as the head puts me into type 3 (improved production) at the local hillclimb, whereas a stock head would put me back to type 2 where I would be very competitive. I didn't think this through carefully enough when I picked up the 2nd hand head when re-building the motor and I doubt if I am getting a great benefit without cams, etc to make full use of its potential.

If I went back to clubman I would keep the lsd, swaybars and fit adjustable koni shocks with stock springs and go from there.

I will run as is until I wear out the R888s and sort something out for the 2012-2013 season.

[PeterB]

The left hand oil seal is now replaced on the Torsen and all seems oil tight now. A $20 part but several hours work, a bit more difficult due to lying on a concrete floor at about 5 degrees - hands don't work too well at this temperature. Only difficult bit was getting the drive shaft out due to limited access, and trying to clean underneath the car.

I have also fitted a Rspeed OEM style front lip - looks good and may assist cooling in summer.

Replaced the window seals on the doors as the old ones were badly weathered. The car would be looking good if only the paint was better.

I am running NB8A 15"rims with Pirelli tyres on the road. I think they look good on the red NA.

Carco rebuilt 1600 with cleaned up ports -
12 degrees advance, running on 98 ulp as compression unknown
NA standard exhaust system (needs upgrading).
DDMWorks pod filter with heat shield from Rspeed (replaces stock air box).
NA standard radiator with plastic panel to help airflow.
1800 clutch.
NA6 5-speed with new gearshift kit fitted.
Torsen 2 lsd with 4.3:1 ratio, NB driveshafts and tail shaft (ex NB automatic).
New rear wheel bearings and drive shafts rebuilt.
NB KYB AGX adjustable shocks with Ground Effect springs (375 lb front and 250 lb rear).
Camber : front -2.2, rear -1.8 with maximum caster at front.
Red (?) aftermarket swaybars (rear adjustable).
Carco front swaybar brace (to stop mounts cracking again).
Mania front and rear underbody braces
Slotted front NA disks with Hawk HP+ pads (great on the track, but noisy and dusty on the road).
Stock rear 1600 disks and Lucas pads.
NA lined hard top with demister (soft top removed as damaged).
Full interior trim.
NB Brown-Davis steel roll over protection system (can be CAMS approved).
Sparco Sprint drivers seat on re-drilled NA seat rails.
Monza 3" 6-point clip-in harness.
Drift flat bottom steering wheel (same bolt pattern as original Momo) - to better clear long legs !
16x5.5" rims with Toyo R888 GG semi-slicks 205x50x15 running at 32-33 psi hot for track.
NB8A 15"x6" with Pirelli road tyres for street
Rspeed OEM style front lip.

Great little car - I am having a ball in it.

[PeterB]

I ran the hillclimb at Canberra on Sunday 21st along with five other MX5s, with mixed results, but had lots of fun trying to run down a quick Toyota Sprinter 1600. Gave him a scare, but couldn't catch him.

I have to run as Type 3 in the hillclimb as their rules don't allow for the head ports to be cleaned up, whereas you can for Type 2 in supersprints !! I should go back to a stock head as the class record in type 1/2 0-1600 is 89.06 (50.42) which would be achievable in my car with a stock head and a decent exhaust, as it wouldn't lose much in performance as the exhaust would more than offset any loss from losing the head porting.

I ended up 2nd in Type 3 0-1600 with a 87.77, (but did do a personal best on the usual first lap of 50.46). The Sprinter got a 87.32 and we both missed the class record of 87.11 as it was a coldish day - a bit tricky when you don't get to warm up your tyres. We both had of track excursions on the first colder run.

The hillclimb is of course a standing start and you run it all in 2nd and 3rd gears, so is more technical than sheer speed (like Marulan), but a blind, off camber and downhill corner in 3rd gets the adrenalin running.

The Torsen seemed to be working well and didn't explode like the viscous diff last time.

I will miss the next MX5 trackday, so will try to get a decent 2 1/4" exhaust and high flow cat (still running a stock exhaust) for the next state supersprint round.

[Jeo]

You take the last corner in third? I'm going to have to have a chat to you about gears and braking points next time Peter

[PeterB]

It varies depending on grip levels.

Launch in 1st, grab 2nd before the first left hander (even if I short shift a bit), then hold 2nd across the bottom, up the hill (even if on the rev limiter as it won't pull 3rd up hill) and around the top corner. Grab 3rd in the dip and hold through the top corner and down the hill.

On a grippy day I hold 3rd through the bottom corner over the finish line, but if it is a bit slippery like last Sunday I grab 2nd going downhill into the last corner to help stopping and get better balance through the corner.

Last Sunday was a 2nd gear bottom corner day.

[Jeo]

Ahh, good to know. I'm currently going...

Launch in 1st, grab 2nd before the first left hander (even if I short shift a bit), then hold 2nd across the bottom, up the hill (even if on the rev limiter as it won't pull 3rd up hill) and around the top corner. Grab 3rd in the dip and back to 2nd for the top corner, change to third about a third of the way down the hill, back to second for the last corner and holding second across the line.

I'll have to have a play at the next event.

[PeterB]

Missed the last hillclimb and track day as my wife tripped and broke her leg, so I have been playing houseboy. It happened in the horse paddock, so lucky some-one rescued her before the vet arrived. She is now mobile again.

I spent my spare time putting 4 new KYB shocks into Helen's NB8A - I lucked onto 4 new shocks off ebay as an end of financial year sell out for $236, so with a day of my time this was a very cheap shock upgrade for a NB - sometimes you win one.

I am entered for the state round this Sunday, then the track day the following Sunday so will make up for lost time.

I have put in new brake pads for the track day - Hawk HP+ NA6 (from Mania) for the front and Lucas road pads (from Carco) for the rear.

The previous Hawks went in last November (running on rda slotted rotors), so I would have got a full season of supersprints (all but one MX5 track days plus some state rounds), two hillclimbs and general driving out of them which is pretty good. There is enough left on them to keep as spares.

I hope we get one of Bryan's optimal air pressure days so I can try to get into mid to low 14s.

[PeterB]

Another good day at the State round on 16 October, resulting in a new personal best in this car of 1.14.624.

2nd in type 2A behind an unbelievably quick Honda Civic who did 1.10.8, but has a best of 1.09.98 !!

Despite bedding in the new brake pads well on the street, it still took a couple of runs for them to get fully operational, but after that it stopped well.

Good warm up for next weeks track day against the Victorians.

[Guran]

Congratulations Peter. It was great fun trying to chase you down ... though I didn't have any success with that once you got your brakes working properly.

[PeterB]

Another trouble free day at the interstate challenge although it was very hot, with another small reduction on my pb down to 1.14.56, (but beaten into second in class 5M by Bevan from Victoria who drove very well to get down to 1.14.11 for the class win).

Almost every run today included a 1.14 (even a 1.15.0 whilst crossing the finish line backwards) so I am gradually getting the idea of how to drive the car and will keep working at catching up to the young guns.

[PeterB]

My entry is in for the November 20 hillclimb, then December 4 trackday to finish off the year, but it looks like I need a new alternator first - a blow to the budget.

I was looking at my progression of lap times at Wakefield and it shows a slow but steady progression :

My best on brand new Kumho KU36 on an ideal day was 1.16.28 (other track days on KU36 were in the 1.17s).

After fitting the R888s semi slicks it has been a steady improvement on each subsequent track day :

1.15.52, 1.15.02, 1.14.81, 1.14.62, 1.14.56.

Usually on a day I struggle to get a pb, but at the next track day I quickly equal that pb and then slowly improve on it - proves that lots of it is in the mind and each time you improve on one corner that becomes locked in and then you can move to improve somewhere else.

However, december is usually hot and slow, so it will be interesting to see if I can continue this trend.

[PeterB]

Fitted a new alternator as the charge and brake warning lights were both on and voltage was 12.7 with engine off and only 12.5 with engine running - so no charging.

Old alternator confirmed as faulty so a new one has gone in (thanks to Dave at Carco) and all the red lights have gone out and the car is running at 14.7 volts.

Ready for the hillclimb.

[PeterB]

I had to miss the Nationals at Eastern Creek as any spare cash I had went on the new alternator and getting tyres sorted.

I had the Toyo R888s reversed on the rims so I can swap them left to right, as they were wearing unevenly as all tracks I usually run are clockwise, so the lefts cop most of the wear.

Ran the Fairbairn Park hillclimb on a damp and cold day. Wakefield Park can be a lot of fun in the wet, but the hillclimb not so much.

The new alternator didn't help to keep the rain away, but the car ran trouble free. I managed only a 52.61 compared to my pb of 50.46 so was well off the pace - couldn't get any tyre temperature.

Was getting a lot of axle tramp on launch as on my runs it was too wet for a clean start, but just dry enough to get some intermitant grip.

Hope for a better day at Wakefield Park.