Patrick's 1986 944 Turbo by 333pg333

13 minute(s) of a 264 minute read

Did some more testing yesterday. Amongst other things we found that by increasing the angle of the 2nd smaller vane on the rear wing we gained top speed down the main straight! Riddle me this?

Pretty much spot on Colin. Better exit from preceding corner. I don't have all the stats to hand but that's the gist of it. The corner speeds were pretty low too. The one leading onto the main straight is very tight and also bumpy. So it's really easy to not get quite right. Map is kinda wonky but you get the idea. Track runs Clockwise.
Not the track we will be running on in Competiton in 2 weeks. That is faster and more flowing. 

Drag and downforce would have increased with the more aggressive attack Elliot but as there was greater corner exit speed, this overcomes the extra drag.

The difference between the 1st test day and yesterday was that we raised the the front ride height a little as the springs had settled. We have to be 65mm above the ground at resting ride height. We knocked a little bit out of the front camber so it’s back to just over -3^. Raised the rear ride height a little yesterday and wound in some rear sway bar. The corner speeds were quicker which translated to the improved straight line speed. The only thing I didn’t confirm was how it changed the downforce at the same part of the track.

3/18/14

I know this car has had saturation coverage and had to think before posting but I guess it’s worthy of another one. Apologies to those that are over it!

Got it covered in a local car mag down here. (No, it’s not a Mazda magazine!) Got a nice article and the ‘Centrefold’ too.
As it’s taken some time to finally hit the stands there has been some changes already to how it appears in the article. Gone are the ‘busy’ dive planes and we’ve also cut away at the rocker panels.

Another recent article on the Time Attack website.
http://www.worldtimeattack.com/index...nues-to-amaze/


This was all done very recently and haven’t tidied it up yet. More to come as we’ve had a 2 day consultation with a well-known US Aerodynamicist, the aptly named Andrew Brilliant. Very interesting stuff indeed. Amazing how some seemingly insignificant changes can create big gains in downforce. We are going to nip away at the changes over the year with the WTAC 2014 being the objective. At the end of the main straight in the event in 2013 he calculated our car was showing over 1000kgs downforce on the rear while we had -90kgs lift at the front! Yikes! Makes me shudder thinking about that considering the little incident I had in 2012! He was actually highly surprised that we even got the times we did under such circumstances. So the whole emphasis is on increasing frontal downforce for this year. This will be achieved through changes made to the splitter, end plates, rockers, fenders and some more venting on the hood. To achieve some of this we will actually shorten the radiator at the base, remove the large air to oil cooler and convert to water to oil and move the enclosed air filter higher. This will allow us to create an actual working or active splitter with diffusers that will create a lot more downforce than our current slab of wood. He is confident that we can improve our laptimes significantly. Even with the minor changes we were able to do some improved times 2 weekends ago at Wakefield Park which is a short, tight track. Car also feels a lot more alive with the smaller more efficient GTX3582 and a change in fuel. Hopefully some more improvements are not too far away.

Not a great video but it certainly looks faster up the hill and along the back straight. Was a fun day as I am starting to get more comfortable in the car again. Managed a 1.02.9 myself which was a 4 second improvement from the last time I was at this track. Paul was super close to breaking into the 59 sec barrier which carrys some kudos. He did a 60:00.7 and was showing 59.6 on the predictive timer with 2 corners to go. We had a few minor glitches at the end of the day which prevented us going out again which was a shame. The bolt in our RH engine mount broke and Paul suddenly had some interesting steering changes! Something to aim for next time though.

3/19/14

Sure. I thought it was posted elsewhere. Unfortunately the dyno chart isn't of much help as it was done on a different ramp rate according to the operator.
I don't quite understand but from what he said (briefly) he loaded it up really slowly to get a better tune. Said he got more timing into it as well. The chart looks slower than the previous turbo which doesn't make sense as I know it's more responsive.

1st one was the BW hybrid. 2nd is the Garrett.

I wish I could get more info out of the tuner but I can't ask him everyday for the maps/charts. He's a really nice guy when I see him but just seems to be super busy and often working well into the night so it is what it is. As mentioned, I don't think we can compare the charts completely apples for apples due to different ramp rates and possibly temps. He also said we had problems with wheelspin due to the slicks turning to mush at some stage this time around.
I guess apart from the coolant issue, we have a great motor for the time being and the bottom line is laptimes. Having the fastest RWD T.A. car at the shorter track is a sign of things to come. We've got more improvement to come which is exciting.

Colin, the calcs were done on the car as it was in 2013. With the splitter and dive planes. I was amazed and couldn't believe with our fairly significant dive plane 'extravaganza' that we were still showing lift!
From what I've heard, read and seen, Diveplanes/Canards etc are not what they appear. Unless you did some pretty significant aero work yourself, I'd not go there. At best you'll get some downforce but with that will always come drag. At worst, just drag and possibly lift. Perhaps those really small ones that Tony G had on his Red car might be worth a shot. I think they were off a Cup Car. I've seen a lot of people removing their Diveplanes so it's not all as obvious as it would seem.

Ok, finally some more info. Interestingly the boost comes on much earlier when comparing these two pulls.
Here’s a bit of an explanation from the dyno operator:

“I have attached 2 files. The 1st is boost. 2nd is torque. These overlays are at different ramp rates. This shows the problem we are faced with turbo cars & ramp rates.

The higher horsepower reading is in shootout mode which is the correct ramp rate to show the correct horsepower/ torque readings. Unfortunately this does not allow the turbo to spool so therefore shows the boost coming in later. The slower ramp rate also overheats the tyres causing wheel slip. “

So this makes a lot more sense in terms of what we’ve been ‘feeling’ by the seat of our pants. Very different curves and response rates. Going to get the Ign map too.

5/22/14

A few updates occurring right now.

We discovered the last time out that we were running out of front brakes. They were Big Reds on 2 piece floating/slotted 332x32mm rotors. I had purchased a 2nd hand set of 997 Cup Calipers that were repainted and refurbuilt in the US some years ago. Due to various reasons they hadn't been sent down to me until recently. I had also wasted quite a lot of time and money trying to source some larger 350mm rotors to fit with the Mo30 uprights but that just didn't work.

So we then decided to go with the later sized Cup rotor of 380mm / 15" but that was going to be a really tight squeeze in under our 18" wheels. Finally we decided on ordering some custom rotors and hats from Coleman Racing which were 375x32mm. These finally arrived (although they made a mistake when converting mm to inch which resulted with the inner face being 9mm shorter than we ordered) and we went to fit the Cup Calipers. Unfortunately they had been put back together incorrectly which resulted in the Ti pistons being damaged. Further investigation shows that it would cost something like $1500 to rebuild both of these calipers and also the more I read, the more I found out that the Cup Calipers aren't viewed as a true race quality version. Race teams have to run them but they probably toss them away after each meeting as they're subsidised when buying them.

So, after more frustration and wasted time we decided to ditch the Brembos and go for some 6 piston Alcon calipers and make up the adapters here. These are the same calipers that were used on the Aussie Supercar V8's for many years so they are well regarded as being of stout quality. Interestingly when we compared the previous rotor and caliper vs the new larger setup, the new one is slightly lighter which is a bonus! Another thing was that these calipers have much larger piston area so we've had to change the master cylinders to adjust for this. The Cup calipers have 28,30,32mm pistons vs 30,35,38mm pistons for the Alcons. Which also means that the piston area covers all of the pad. Incidentally I had also bought 3 sets of pads to work with the Cup calipers so have learned that it is possible to cut them down to fit the Alcons but Paul will be coughing up some interesting substances today!

A further change to the car involves the front sway bar. Due to changes we are going to be making to the splitter we have to make room. One of the things that had to move was the front sway bar. So we've made a pretty trick custom setup which has it positioned behind the front Axle line. In addition we get less drag with it more out of the airstream too. There are blades on each side of the cromoly bar and it will have in cabin adjustment via the control unit pictured. Both these new additions plus a new wider version of the front splitter with new end plates (all the dive planes have been removed) will be tested this weekend at the track.

The next steps will be to shorten the radiator from the base upwards, change the p/steering pump to electric and convert the large air to oil cooler to a water to oil version. Both these will be moved from the front of the car. What we are chasing is better front down force and to do this we have to make significant changes to the splitter and also reduce frontal drag. Clearly the rear wing is overpowering the front and we are concentrating on removing as much underhood pressure to do this. The front of the rocker panels have been modified and we'll be making more changes to increase the release of this pressure. Aero is way more important than extra ponies at this stage. Amazing how some apparently minimal changes make a difference too. Angles of vents, panel gaps etc...Aero is King!

Pic of brakes under 18" wheels.