Track fun from past years

It is amazing to watch old track videos and realize that nothing major has happened. Especially when bunch of eager amateur weekend racers want to show their best, someone should definitely hit a barrier or some other obstacle. Well ok, sometimes that did happen but luckily no one got seriously hurt!

I have selected here a couple of videos from the past seasons for you to watch. Back in 2008 youtube had only limited capacity for video uploads and that shows. I filmed the earlier videos with a Panasonic compact camera. It recorded quite decent 480p video, but it had to be heavily packed to make it fit youtube’s limitations.

Hope you enjoy!

This was filmed during Radalle.com track day in 2008. These events are open to everyone and usually very crowded. Lover than average video quality, noisy audio but lots of overtaking with 132 hp Miata!

Best parts in first 5 minutes.

- Mitsubishi EVO, Mk1 Supra, Opel Omega, RX-7, Porsche 944

http://youtu.be/f0tbbV3bmUI

Screaming 8000+ rpm single lap from 2010! Revlimiter was set to 8500 rpm since engine was still making good power up there and I got away with fewer gear changes. Very nice engine tone from open cone filter and aluminum intake plumbing, average 480p video quality and some tire squeal.

http://youtu.be/uY1DJn1bRdc

Open racing practice in 2012. This was my first video with multiple angles. Nothing really special happens here, some corner exit power slides, one mild-ish throttle tap drift at 3:32 and two race cars. Put HD720 on!

- Legends race car, Citroen DS3 R3 rally car

http://youtu.be/1VB9yoYNxrg

Miata Club of Finland’s track day at Alastaro in 2013. A fellow member wanted some footage of his driving, so I tried to keep up with him. 100hp/Nm extra makes a difference! This was also a test for a chin mounted Hero2-camera. Put HD on!

http://youtu.be/skQeCtts8Ms

Radalle.com track day at Motorpark in 2013. This stint turned out to be a true -90’s battle!  At 1:20 I let a Ferrari 348 TS pass me and then followed it. Eventually we caught a Honda Civic VTi with slightly tuned B18 that was competing in Time Attack Club –class. We passed it and after that also E34 5-series drift car. Audio quality is not good. Hero2’s internal microphone is poor and open top makes quite lot turbulence. Something to be dealt with…

http://youtu.be/hbE9ZjAYQpE

Need 4 Suspension

Let's face the fact; my MX-5's suspension is stock. Yes, I have done some improvements and installed a couple of upgrades but neither Koni Sports Kit nor a set of H&R anti roll bars really mean it's race ready. The car is drivable and pretty fast by all means and the whole package is in balance on the track. Obviously I have learned to adjust my driving style according my current setup. I could benefit from having 100 extra horses under the hood, but after that current balance would be gone. Further engine mods have to wait for a while then.

The best single handling mod so far has been my current tires. That was no surprise! Before that it was racing inspired wheel alignment and before that Koni’s sport suspension.

Real need for further upgrades came along with stickier tires. My current Yokohama AD08s offer a lot more grip compared to Toyo T1Rs. Higher grip has resulted in increased compliance of the suspension. Increased roll and change of the tire alignment in fast corners are the symptoms. T1Rs in the front wore evenly but AD08s are starting to take the heat more on the outside of the tread. So, what is happening here? Obviously 22 years old stock bushes are starting to give in and my camber angles are “dialing in”.

The other issue is decreased chassis rigidity. Front and rear are starting to feel even more detached than before. When a pot hole or a kerb on track is hit, a horrible wobble occurs. If car is jacked up from only one point the flex can be seen with bare eye when the door seams are not in line anymore.

Here is what I am planning to do. First I am going to get the front and rear attached again by installing door bars. After that polyurethane bushes and some sort of coil over solution have their turn. Stiffer bushing and springs won’t have their full effect without increased chassis rigidity. I want my suspension to do the work instead of the chassis.

MCF meet in Hyvinkää

Miata Club of Finland arranged 2013 summer meet in Hyvinkää about a week ago. I took a few pictures of some chosen cars that showed up.

CLEAN BLUE NA

Two early 90’s NA Miatas in blue caught my eye immediately. The other was very nice and clean on Enkei Apache II rims. Tein suspension gave it a nice balanced stance and combination of paint, rims and some details was really working!

SLAMMED BLUE NA

The other was built with different goal. It was slammed and had a racier look. Nice details were there also and pink with blue seem to work together nicely. Still, highest points go to center console decoration!

NA Miatas - they are simply fabulous!

Season 2013 starts

First ride and first photos for this season!

More NA POWER part 3!

PREVIOUSLY ON "MORE NA POWER..."

Let’s drill deeper into tuning a naturally aspirating B6ZE for more power. Until now we have done all the basic bolt-on upgrades in part 2. Better flowing intake and exhaust are in. Ecu has been left stock with only mild adjustments to AFR and ignition timing. These modifications gave us about 85 crank hp/liter from 1597 cc engine.

See also 'cam specs and timing' in More NA POWER part 4.

ECU UPGRADE

Next there is the programmable aftermarket ecu. Nowadays many have opted for Megasquirt which is an affordable choice with good online support. Aside the make of ecu, what matters is that with fully programmable ecu it is possible to fine tune ignition and fuel tables for every setup. A chance to get rid of possibly restricting AFM or MAF is also an added bonus. Here is a dyno comparison which shows nicely how some 10 extra hp can be found by getting rid of stock AFM and tuning the ecu. I must mention that ARC intake was also installed, but I have no idea what kind of an effect it would have alone. 90 crank hp/liter is pretty nice for B6ZE with stock internals.

INTERNALS

Most of high power B6ZEs are equipped with 80,5 mm (or so) diameter pistons. Larger bore increases displacement to about 1700 cc and high compression pistons also rise compression ratio from stock 9,4:1 to 10,5 or even 12:1 –depending on the piston design. Both serve the same purpose: pumping torque up from bottom to top. And then there is The Flow. In order to make high power in high revs the head must flow properly. In addition either exhaust or intake must not form a bottleneck for the gas flow. Bigger cams, larger valves and head porting all serve the same goal: better exchange of gases in the cylinder. And don’t forget high quality, light and balanced internals like valve train parts, conrods, crankshaft and flywheel, if you also want your engine to last long in high revs. Here were the starters.

SAME GOAL, TWO PATHS...AND TWO RESULTS

At last we come to main course. Here are torque and power figures from two different engines. They are plotted into same graph and presented in wheel Nm and hp to make comparison easier. Original data for both is taken from chassis dyno graphs presented in wheel torque and power. So the only “manipulation” that I have made is torque conversion from lbft to Nm for the Engine nro 2. Power was calculated from torque in both cases. Still some consideration is required! I don’t know in which conditions Engine nro 2 was originally tested, what type of dyno was used and what was car’s actual drivetrain setup. So the figures presented here are not 100% comparable. “Are not 100% comparable”, what does that mean? It means that I, or anybody else, can’t state that engine nro 2 is “exactly” 10-20 Nm stronger than engine nro 1. But yes, nro 2 outflows nro 1 above 7000 rpm. That is “sure”.

Engine nro 1’s specs:
• Toda 81 mm bore pistons (1720 cc)
• Carrillo A-beam rods
• Balanced stock crank
• Street ported head, stock size valves, 3-angle valve job
• 272 degree cams, 9 mm lift
• Stock intake manifold fitted to throttle body and head
• Stock 1.6L throttle body
• 4-1 Racing Beat header, 2” pipe after collector

Engine nro 2’s specs:
• Maruha (Mahle) 80.5mm bore pistons (1700 cc)
• ETD Rods
• Knife-edge Crank
• Race head with oversized valves (ported and polished)
• 284 degree race cams (possibly 10-12 mm lift)
• Maruha ITB
• Racing header, 2,5” pipe after collector
• (This data is from winkyl’s engine taken from clubroadster.net and youtube.com.)

CONCLUSION

As was mentioned before, the aim of the comparison is not to stare at the numbers. The shapes of the torque curves are the most interesting part. Power band for both engines starts from 3500 to 4000 rpm. It doesn’t mean that nothing happens below that. There is more torque at 2500 rpm than in stock engine at 5500 rpm. The biggest differences between these two power plants are above 7000 rpm. Nro 1’s torque starts to drop from 6750 rpm and power reaches its peak at about 7000 rpm. Winkyls’s engine keeps torque up until 7000 rpm. And more importantly, the angle of descent is gentle enough to keep power rising until redline at 8000 rpm. I wonder what figures would be with higher redline!

This comparison isn’t the best demonstration of camshafts’ effect on torque and power since the other engine is equipped with stock intake manifold while the other runs on ITBs. Stock manifold possibly forms a bottleneck for airflow. However, the reason for broad power band up to 8000 rpm+ in engine nro 2's case is evident: High flowing head, larger valves, 284 deg. high lift cams and ITBs are the main factors.

See also:
More NA POWER part 1! and
More NA POWER part 2!

Ahvenisto lap comparison – 3 times NA Mazda MX-5

THE TRACK

I’ve spent most of my track time in Ahvenisto Racing Circuit. It is by far the most demanding race circuit in Finland. It’s technical, it’s beautiful and it’s legendary. And perhaps it’s world famous already since Captain Slow visited it with Mika Häkkinen – a Formula1 double world champion. http://www.youtube.com/watch?v=2bmqdnx5R1U

Ahvenisto Racing Circuit is built in late 1960’s and that makes it a bit different. It’s like Norschleife’s little brother. Most of the time it’s either uphill or downhill and there are no real runoff areas. Difference between the lowest and highest point is 30 meters (100 feet). It’s pretty much for a track that is roughly 3 km long. No picture can communicate track’s true profile. Incar videos give a hint but this track is something one must experience personally.

Enough with the praise. Here is some data extracted from this video  http://www.youtube.com/watch?v=Ft3Cx6fHrhI&feature=youtu.be. Here is some basic steering, throttle and brake input data to tell its own story about track’s profile.

Lap time (dry weather): 1´38 s

Steering wheel straight forward: 22% of the time

Wide open throttle: 43%

Foot on brake: 17%

Throttle partially open: 40%

Longest time throttle is continuously 100% open (including gear changes): 17 s

THREE CARS, THREE LAPS

Next follows a brief analysis of three laps done by three different MX-5s. They are in many ways similar but at the same time totally different. I will call them Silver, Red and Green. They all are from early -90’s with B6ZE engine.

Red’s specs:

- About 120 crank hp, completely stock engine with silenced decat pipe, 7200 rpm rev limiter

- 4.1 final drive with torsen type-2 differential

- BC Racing BR coilover suspension, Energy Suspension poly urethane bushing, stock stabilizers

- Track spec wheel alignment

- Yokohama Advan AD08 tyres, 205/50/15

- No roll cage or roll bar, P5 frame rails
- Lap time 1:39.5

Silver’s specs:

- About 130 crank hp with intake and exhaust mods, 7200 rpm rev limiter

- 4.3 final drive with Kaaz 1.5way L.S.D

- Tein SuperStreet coilover suspension, full set of poly urethane bushing, stiffer front stabilizer (22 mm diam.)

- Track spec wheel alignment

- Toyo Proxes R888 tyres, 195/50/15

- Full roll cage, interior strip down to compensate cage’s extra weight, plus no air-con and power steering.
- Lap time 1:38.5

Green’s specs:

- About 160 crank hp, 8300 rpm rev limiter.

- 4.3 final drive with Kaaz 1.5way L.S.D

- Koni Sportskit suspension, stock bushing, H&R stabilizers front and rear

- Track spec wheel alignment

- Yokohama Advan AD08 tyres, 205/50/15

- 6 point roll bar
- Lap time 1:37.5

Colors painted on the track illustrate gears: light green is 2^nd, yellow is 3^rd and orange is 4^th. Numbers in the boxes are “gear”/”revs” and speed below (in kph).

Okay, what does this tell then? First take a look at the gear changes. Red changes gear 6 times per lap because of the wider total gear ratio (4.1:1 differential and large tyres). Silver must change gear 10 times per lap (shorter overall gear ratio). Compared to Silver, Green’s total gear ratio is similar but Green benefits from higher rev limiter set to 8300 rpm - hence 6 changes per lap for Green. Silver’s extra two up and down changes both come in bad places. The first is before turn 3 where all the concentration should be aimed on upcoming left turn heading uphill. The second is between 8 and 9, on an uphill, not the best place to shift up either.

Next take a look at the table with cornering speeds. It’s interesting to notice that all three have almost identical cornering speeds in 5 turns out of 11. Track is very technical from turn 6 to 10 and the trick is to keep up the momentum. It’s basically one big complex of turns where clean driving and good handling is rewarded.  In paper Silver should have highest apex speeds as it is equipped with a set of R888’s.

After turn 10 it’s flat out for a while. Keep the throttle floored through turn 11 and get your top speed measured before going on brake and diving into turn 1! This half of the track from turn 10 to turn 6 holds all the straights - or not so curvy parts. High powered cars gain some ground here but are usually caught between turns 3 and 5 if drivers aren’t familiar with the track. Turn 11’s apex speeds show Silver’s more favorable gear ratio and power over Red’s.

Technicality of the track, the effect of gearing and apex speeds were three most important things I wanted to highlight here. Power isn’t everything in Ahvenisto and skillful driving is a key to success. Please continue checking the graphs by yourself – there is plenty of more to be found!

Practice, practice, test and practice…

This season’s first handling modification was a set of H&R adjustable anti roll bars. There is two possible settings in front and three in the rear. I decided to try something in the middle. Well, I couldn’t do that because while lying on the garage floor (car was jacked about 30 cm of the floor) all my muscle seemed to have disappeared somewhere and the front was set “stiffer”.

Testing took place at Ahvenisto Race Circuit. With stiffer anti roll bars corner turn in felt immediately more responsive and weight transfer was noticeably quicker. This is what these parts are for and they were doing their job nicely. However mid corner- and corner exit oversteer was kicking in. One had to be very careful with gas. Let’s see how milder rear setting affect…

Wednesday is the day for free practice session for everyone. There was a couple of modern formulas (F3 class?) and older ones also. Bikes had their fun for the first half of the day and left the track for cars when it started to rain.

I managed to drive both on dry and wet track. I really enjoyed driving in the rain because limits could be found at lower speeds. The other agenda was to shoot some film and test new Hero 2 –camera. In car pictures shown here are from testing different helmet mounts. “Chin” is a bit too low and I believe that “fore head” makes a better angle.

Just can’t wait for the next visit! http://www.youtube.com/watch?v=1VB9yoYNxrg