Thursday, December 3, 2009

911 rsr testing, one-two…

A long day.
by Pierre Martins

What’s better than spending a day at the track behind the wheel of a powerful old-school 911 RSR? - Spending the day behind the wheel of not just one, but two RSRs of course. So without further ado, allow me to introduce the cars to you;

I’ll start with the white car.

‘73 RSR, 3.5L engine pushing out around 350 horses, delivered through a close ratio crash-box. Porsche used to experiment with 3.5L engines once upon a time but never released them on the open market, so the 3.5L boxer engine is quite a rare find these days.

The car was built from the ground up by M&R Motors about ten years ago for Keith Rose, who’s been campaigning the car with great success in Historic Racing ever since, mainly at the Killarney circuit in Cape Town.

Midvaal_PorscheRSR_031However, the car has had a few offs over the years and some butcher mechanic in Cape Town put an angle grinder to the rear RSR suspension pickup points, heaven only knows why. People who don’t have intimate knowledge of these cars should never be allowed to work on them, in my not-so-humble opinion.

I tested the car at Killarney a few months ago and it had such bad bump-steer that my arms were sore the next morning from the steering wheel kicking back violently three or four times in each and every corner. Some bright spark decided to lower the ride height of the car without taking the tie-rod angles into account.

The rear end was also doing weird and stupid things, and quite frankly, I was appalled by the piss-poor handling of Keith’s white RSR. But that’s all besides the point now. Keith sent the car back to Mario at M&R who stripped it and stuck it on a chassis jig to check it for straightness and fix the butcher job on the rear pickup points. With that done, Mario installed a new crash-box using straight cut gears in the car’s original 915 gearbox. Finally, he worked his usual magic with regard to suspension setup for the track.

Midvaal_PorscheRSR_030But more about the white car later. Let me first tell you about the yellow car:

Different kettle of fish altogether, this one. We call it the ‘Yellow Bird’. I was first introduced to this 380+ horse power IROC-replica RSR back in 2007 when Mario asked me to test it for its owner, Dave Fourie, prior to the local Porsche Challenge Unlimited series, in which the car took overall and class honours that year.

You can read the story about Dave’s 2007 season
by clicking here. You’ll love it.

I’ve also added a photo journal of the original build process elsewhere on this blog. You can view it by clicking here.

Anyway, the car has undergone extensive development since those days. Off the top of my mind and in no particular order we’re talking 3.8L, 964 casing with proper RSR internals, cams, PMO carburettors, close ratio crash-box, new lightweight 17” BBS-style split rims, bigger brakes, fuel-cell, new lightweight doors and bumpers, custom made Polycarb windows all round and whatnot. The list of improvements reads like a grocery list, so let’s just say that no expense was spared in the quest of creating one of the best as far as RSR replicas go.

In my opinion, Dave’s Yellow Bird is certainly the best example in South Africa, and would probably rate pretty high if there was such a thing as a world wide scale of competitive ‘74 IROC-RSR replicas. The car is now reaching the final stage of development, the ‘salt & pepper’ stage, as Mario calls it, with the latest upgrade being a small fortune’s worth of super trick stabiliser bars from Smart Racing in the States…

Midvaal_PorscheRSR_006 And so it happened that we decided to kill two birds with one stone by testing both cars back to back on the same day.

We opted for Midvaal Raceway just south of Jo’burg. It’s hard to believe that Michael Schumacher once tested a Benetton F1 car at this very track, but that’s another story. The place has been little more than a dilapidated dump for a number of years now, but remains a popular testing venue due to the amount of track time you get for your money, as well as the fact that Midvaal is quite a hardcore technical little track with a knack for exposing any track car’s hidden weaknesses in just a few laps. Get a car to work there, and it will work at just about any other track, sans minor tweaking for each track, of course.

As a side-note - I see it as a privilege to be able to test drive special machines such as these Porsches on race tracks and believe that one should always spread a little goodwill around, so that’s why I regularly invite someone to join us on these test days. On this occasion I invited an up and coming local photographer and petrol-head, Waldo Swiegers, along for the day. All the photos on this page were taken by him and you gotta admit, the young man has talent.

Waldo is a freelance photographer, based in Pretoria. He specialises in Individual car shoots. You can reach him on his cell: 084 824 0392 or by email: 

By the way, all the photos on this blog are thumbnails of larger versions. To view the bigger photos, just click on any thumbnail and use the ‘back’ button on your browser to return.

Anyway, Dave drove down from his hometown Nelspruit and Keith flew in from Cape Town for the day. My job for the day was to test both cars, give feedback to Mario on setup and assist Dave and Keith so they get the most out of their cars. First order of the day was Keith’s white RSR. I only needed five laps to figure the car handled sweet, the rapid-fire bump steer and stupid rear end antics the car had when I last drove it in Cape Town were gone, so I handed it over to Keith and he pretty much had a ball in the car for the rest of the day.

He didn’t know the track from a bar of soap and this was the first time he experienced a whining crash-box, but he learned the lines, got the hang of clutch-less shifting and got quicker with each session. So did the smile on his dial. The man was happy.

Midvaal_PorscheRSR_013 Between sessions we discussed the added benefit of left foot braking you have with a crash-box. Not having to worry about the clutch means that you have your left foot doing nothing, so why not use it to help transfer load to the front end of a 911 when it tends to push? Some drivers have a real problem with left foot braking. First try they tend to hit the brake pedal with the same amount of force you’d normally use on the clutch pedal, which is way too much and they think ‘Shit! - I better not do that again…’

I believe it’s not really that difficult. Most drivers can do it, they just don’t know it. It’s just a mental block that can be overcome with a little practice. Think about it like this – You can put just about any driver in a single seater or go-kart and they will left foot brake pretty well without effort. In a kart you have the steering rod between your ankles, making it impossible to right foot brake, so your brain automatically adapts to left foot braking without you even trying. All you  need to do is bring that mindset over to car driving and you’re ‘A’ for away with a little practice. Go on, try it. Just be careful with the amount of pressure you apply to the brake pedal when you use your left foot initially.

But enough of that.

Midvaal_PorscheRSR_020Dave’s Yellow Bird started off a notch or two beyond our understanding of the car on this day. Make no mistake, the car was very quick and driveable, but it was showing us the middle finger as far a setup goes. I managed to get it down into the 1’10”s around Midvaal and that’s seriously quick for any tin top car, but the car was a handful and anything but confidence inspiring.

We played around with the settings on the new Smart Racing stabilisers and although that improved the handling somewhat, it also brought other handling problems to the fore. Mario went for the same aggressive caster settings that Porsche used back in RSR heyday, but on this day, on this car, those settings weren’t really working. In the end we reached general consensus that the spring rates weren’t correct in the first place and any settings we tried on the day were just putting band aids on gaping wounds.

But that’s what testing is all about, innit? – To figure things out. I always say that any test day is a good day as long as you come away with enough data to know where you’re at with the car. One thing is for sure – Dave’s Yellow Bird is an awesome car and when we get it dialled in properly, it’s gonna be something else, believe you me. I can sense it. There is potential lurking in this car that can elevate it to something very, very special…

Midvaal_PorscheRSR_032 And so ended another fantastic day at the track. It sure was a long, long day and they kept me busy throughout. Go out for five laps, hand over the car to its owner and tell him what to expect during a quick driver change, give feedback to Mario on the car’s handling characteristics and discuss possible setup changes.

Talk about the cars and discuss the track with Keith and Dave between sessions whilst Mario is making setup changes to the cars. Put my helmet on and go back out again. Give it stick and pay attention to what the car is doing. Come in for a driver change and repeat the same process all over again…

I was truly knackered at the end of the day. But you know what? – I wish I could spend every day of my life like that…


Midvaal_PorscheRSR_003 Midvaal_PorscheRSR_001
Midvaal_PorscheRSR_002 Midvaal_PorscheRSR_005
Midvaal_PorscheRSR_008 Midvaal_PorscheRSR_012
Midvaal_PorscheRSR_014 Midvaal_PorscheRSR_020
Midvaal_PorscheRSR_023 Midvaal_PorscheRSR_028
Midvaal_PorscheRSR_024 Midvaal_PorscheRSR_025

No comments: