Greetings,

I stumbled across this while researching an old race car ...and I'm guessing it's news to all of you too:

http://www.sccatrans-am.com/?p=510

If you are even a casual race fan, and since you are already a Jaguar fan, I think we should all support this effort with our attendance and our dollars. The schedule on the right will hopefully list a track near you.

Trans Am Series races are normally held in conjunction with other weekend race events, so "check your local listings" and you might find even more reasons to go racin'. If you've never been, you will love it.

 

Hey Brute, you see this?

 

Florida isn't on the schedule?? disappointing...

 

Here's what gets me about this whole deal.

I've been trolling Jaguar message boards for about two years. I have seen alot of chatter about performance modifications, some of it by guys who seem pretty sharp and who are very capable at internet sourcing.

Never have I come across a photo, or even a mention, of U.S. based Jaguar racing efforts.

Does anybody know that Scott Pruet clinched the '03 Trans Am manufacturer's championship for Jaguar when he won his sixth race in an XKR that season?

That's not irrelevant trivia to people here. That's where everybody should be looking for the answers to questions about ECM tuning, manual gearboxes, springs and sway bars, pulleys and blowers and intercoolers, blah blah blah.

I'm not going to beat this to death, but here's an example. Say I have an XK, and I want to lower it. Only I want to know how to do it right, so instead of reading chatter I buy a paddock pass and start looking around. Are those stock wishbones? Poly bushings or heim joints? What did they fab for camber adjustment?

Then I hand a cold drink to a crew member on a hot summer day, and ask "who makes your springs?" "Can I buy any of this stuff off the shelf, or are you fabricating it all in house ?"

I used to be involved with racing, nothing Jag, nothing Trans Am...so I don't know how extensively these XKR's, through six years of development and within the confines of series rules, are modified. But that's the first place I'd be looking for the best information I could find on any engine tuning, suspension mods, whatever. Take lots of pictures, watch them set up the chassis, listen in over some shoulders, talk to some drivers, have a great day and click off the freakin' internet.

So I was really surprised when I came across the news about Greg Pickett's recent Trans Am victory, even more so after researching the history a bit. I thought that it would be of great interest to alot of enthusiasts and keyboard racers, and nobody apparently gets it.

Even if you just have a fondness for Jaguars, I'd think this would be more fun then just talking about them, or watching trailer queens getting pushed into line at a concourse. I'd rather be checking out the baddest cats on the planet. Hope to see some of you at Mid Ohio...I'll be the guy with the camera and a cooler full of cold drinks. Click.

 

Hahaha nice JTO, I totally agree, but I am also somewhat guilty of what your talking about.. Although I have contacted Ferlito Motors about their S-Type R, but unfortunately I don't have the time to fly over there to check out their car and take pictures (even though I reallyyy want to)..

The problem with using the Trans Am cars as a reference, in my opinion, is that they are so heavily modified that I feel that most parts won't transfer to a production car. The chassis are mainly tube frame, and these are purpose built race cars with a solid-axle at the back.

The older XKR (pre 2003) Trans Am cars were powered my 650hp carbureted 5.1 liter ford engines.. They also had some astonishing 0-60 times, I think in the sub 3.1 second range.. Originally EFI engines were not allowed, but I think 7 or 8 years ago they opened that up. They have a different set of displacement limit regarding EFI and Carb motor I think. All TA cars have to run a type of street car template, like Cam/Bird, Mustang, Vette, XKR...etc, with set limitation on width of fender, width...etc. Spec rearwing are also required...

The new generation XKR TA is actually powered by a Jaguar engine.. The race engine itself is based on the same all-aluminum 4.2-liter AJ-V8 `stock block` that powers Jaguar`s XK sports cars, the S-TYPE sedan and the aluminum-intensive XJ sedan line-up. Engine work was carried out at Rocketsports' race shop in Lansing, Mich. where Rocketsports' engineers increased the V8's capacity from 4.2 to 4.5 liters and more than doubled the horsepower from the standard 294 bhp (SAE) to over 650 bhp (normally aspirated).

With its race-tuned AJ-V8 revving to 9,000 rpm, the carbon fiber and Kevlar-bodied racing XKR is a very beautiful, fast car. The car will sprint from standstill to 60 mph in a staggering 3.2 seconds, with quarter-mile acceleration in 10.8 seconds at 135 mph, and a top speed of 180 mph.




Thats Trans Am, but there is also the GT3 SERIES.. THIS IS THE CAR THAT WE NEED TO LOOK AT...



In the GT3 series it's Apex Motorsport with the new XKR GT3. In September 2006 Richard Lloyd’s Apex team signed the contract with Jaguar to build and run XKRs in the new FIA GT3 championship. This is not, however, a factory motorsport program and the Apex race activities are independent of Jaguar.

The XKR GT3 retains the same supercharged, 4.2 ltr quad-cam V8 engine as the road going car. The rules allow for alterations to some key components on the basis of durability, and Apex has made some modifications to increase power, now reckoned to be generating around 500bhp.

Cooling is achieved through the use of an air-to-water cooler mounted low down in the nose of the car to cool the water from the standard supercharger charge coolers, with an oil-to-air cooler mounted behind that for the dry-sump oil system. The main engine cooling duties are handled by an NRP aluminium radiator mounted in the standard factory position.



Engine intake air is drawn from vents mounted on the front corners of the car’s nose through a custom carbon fibre box holding the air filter before being fed through to the supercharger.



Power is transmitted to the rear wheels via a carbon propshaft to a 6-speed Hewland sequential transaxle in the rear. Since none of the road going XKRs come with a manual gearbox, this was something that needed to be changed anyway. This change also resulted in an enhancement to the car’s balance by altering the weight distribution slightly to the rear.

The suspension has also been altered by Apex. Using unequal-length double wishbones on all four corners and specially fabricated anti-roll bars, controlled by Koni two-way adjustable coil-over shock absorbers, the car is given a well balanced and reasonably easy handling style. Since professional drivers are disallowed by the GT3 rules this suits the majority of drivers likely to race the car.



Braking at the front is controlled by Alcon six-pot calipers wrapped around 375mm discs, and at the rear Alcon four-pot calipers with 330mm discs. Apex use an AP Racing floor-mounted, adjustable brake bias pedal assembly, with the bias control mounted on the central column below the electrical switches.



GT3 specifies the use of a control Michelin tire in the championship, though some leeway is given on width. Maximum diameter is fixed at 18 inches, since Michelin don’t manufacture 19 or 20 inch tire. 11 inch wide OZ cast magnesium rims are used front and rear. Since the races are all one hour in length, and the drivers are non-professionals, putting wider rims on the rear could be counter-productive. The narrower rims allow the tire to heat up faster at the start of the race.



The car uses the same lightweight aluminum chassis as the road car. All the interior is stripped from the car and a steel roll-cage is fitted to protect the driver. The wiring loom and all computers are removed and replaced with a custom loom (the wiring alone saves 25kilos of weight).



Although the reduced weight of the all aluminum chassis is not such an immediate advantage, given the additional weight penalties imposable by the FIA, its sophisticated bonded and riveted structure makes the car very responsive to suspension and set-up changes.



The main Achilles heel for the XKR GT3 could prove to be the use of the standard Jaguar supercharger: a Roots type blower, where air is forced into the engine using two helically formed counter-rotating rotors. Roots blowers are relatively inefficient, producing the most charge air heat for a given amount of boost pressure compared with a Lysholm twin-screw supercharger. Keeping the charge air cool at high revs, over a one hour race in hot weather, could prove to be problematic. During a warm testing day at Donnington Park, modifications were being made to the air ducting over the coolers and heat reflection away from the intake box for just this reason.

 

You, sir, are a man who does his homework. I have alot to study before the pop quiz, and I thank you for it!

 

Haha your welcome JTO, I knew you of all people would appreciate my writeup and your pretty much the only reason I took the time to type it and you even got pictures too..

 

Damn. Good info here. Loved the writeup (and pics ), WSTR.

 

Hey white STR,

First, thanks for the bitchin' post. When I started to look into the info you provided, I was licking my chops.

This car made a big splash...during a one car test session at Silverstone, in the rain. Well, two cars if you count the ancient D Type it managed to pass. I looked for '07 and '08 FIA GT3 results, and found nothing on Apex or Jaguar. There are two cars in the list of entrants for the upcoming '09 schedule, in a six race series at tracks in:

England, Italy, Germany, Portugal, France, and UAE (at our buddy's home of Dubai).

So I'll agree that it's a nice looking stone, but I've yet to read where it actually rolls.

The series is a cool idea from what I have read: it is limited to non-professional drivers, and the chatter on the 10 Tenths Motorsports site I read leads me to believe this is a buy-and-drive series with a price cap on the cars. But all of that conversation was late '06-early '07, and the thread ended.

So you are quite right, this is the perfect model of the examplar I was hoping to see. Beyond these photos and a video of some puddle jumping, I'm left to wonder if anybody actually saw it.

I'd love to find out I'm wrong, and that the car was campaigned, and represented itself well, and that I could buy rear lower wishbones and adjustable coil-overs from Apex, etc. etc...but if any of that came to pass, I don't think the evidence would be so hard to find.

So I'm going to drop that search, and see if I can learn up on the Trans Am series specifications, and how the Jaguar XKR is outfitted within those confines. Judging from the opening round results, that stone can roll.

Please let me know if you have more info...I'd hate to pack my cooler and head for Dubai for nothing.

See you at Mid Ohio.

 

PS: I think the paddock photos are from the test session at Silverstone. Look at the driver's face in pic #6.... he looks like a pissed off customer waiting in the service department at a dealership.

 

STR, or anybody else who knows/ cares....

So I'm looking at these photos, and I'm trying to learn what I can.

The sequential transaxle sounds like an amazing idea, particularly due to the weight balance aspect, and I'm going to learn a little about those...but what in the heck is inside the transmission tunnel of this car, do you suppose? It it a gutted automatic transmission case with a solid mainshaft and spline driven off the flywheel, or what?????

I'm left to assume, within the imposed restrictions, that the fuel injection system is relatively unchanged from a road car. So where is the MAFS? This one is of interest to me, a couple of years ago I was thinking about a cold air intake setup, and wondered if it was possible to build it with two MAFS and thus configure a system like the one they are using. Not with laundry dryer hose, though.

Do you suppose they have twin MAFS mounted at forward locations? Then I saw the stock XF-R photo that bmw posted, and the twin MAFS are used on that installation. I know nothing about ECM tuning, would you have to reconfigure the software, or couldn't you just wire up the the twins and the ECM would read the aggregate just fine?

Interesting to see that they are not using carbon brake rotors, perhaps not allowed. And if drilled rotors were a good idea, you'd think these would be.

The vertical green rods adjacent to the front and rear shocks...linkage for driver adjustable rate control? I don't know anything about adjustable weight jacking, nor do I see how you could make that a driver adjustable control on this coil-over setup. These just look like the old setup where you set ride height and corner weight with the spring perch, and hit the road.

Front sway bar looks like the formula car style, the horizontal bar connected to the vertical wishbone link rotates to change the rate, so that can also be driver controlled. That could be a street car mod.

I'd love to see it with the front fenders off, to see if the cage extends forward of the front bulkhead. Pretty beefy strut tower braces though, I suppose this IS a worthwhile consideration, even on a coupe. No cross brace though, perhaps because of the way they built the air intake?

The picture with the nose off is with the car on its air jacks, but when they're pushing the stone outside, look at how low it is. That car is what, 3 inches off the deck? With all the downforce that car must be making at speed, I'd think they'd be dragging the front splitter and the skirts on the track. Maybe they never got it going that fast. It must be sprung incredibly stiff, though.

So Apex "reckoned" 500 HP, and then had problems at Donnington with charge air temps. But the Rocketsports bored out stock block is making 650 HP, normally aspitated? Hmmm, time to do some homework on Rocketsports. There surely must be some tips to learn from them that would be applicable to N/A road cars. Can't wait to take a picture of THAT intake/ air inlet setup. I'm guessing it will be EFI, so there should be some relevance.

Observations/ answers/ insults/ ideas?????

 

Rocketsports: (Mainly pub, not bolts)


http://www.rocketsportsracing.com/in...id=6&Itemid=37


And a photo from 2008 FIA GT3, Aston[e] Martin. This one rolls.

Huge fender flares, less front splitter, much larger air inlet then the Jag. Looks like alot more drag, but enough cooling to cure the (Donnington) Summertime Blues?

 

Yeah when I was looking at their intake setup I was at a loss for what they did about the MAF too.. I'm assuming they're using a standalone or a piggyback ECU and were able to tune the car to run with an assumed amount of airflow based on their intake setup.. I'm guessing that carbon or ceramic breaks are not allowed, but those AP Racing rotors they're running are supposed to perform very well. The torsional rigidity on that car must also be outstanding because the bracing and anti-sway bars on it look very impressive and well designed. The suspension is hard to figure out, it has a great number of adjustable components, but I mainly would just want to know who made those coilovers? They might be a tad stiff for street driving, but if we could figure out what fits and just change the springs, we might have something there..

In regard to the fuel injection, idk if it is stock or not.. I noticed quite a few ANL fittings in there so I would guess that they're at least running an aftermarket pump, FPR, and injectors.. The transaxle setup is probably very similar to how they have them in Corvettes, maybe even the same one, because it could easily handle the power..

It's really too bad they didn't convert the supercharger to a Kenne Bell or a Magnusson, that's really the one thing I've been dying to see. I know there are those who have done it, but when its being running at high revs in a race application you know that it can be done *reliably*.. The suspension they are running on that car it probably stiff enough to where the car can't lower more than an inch or so, which is why the increased down force is probably okay..

 

They're Konis, and the great thing about that setup is you can buy any rate you want with any amount of suspension travel you need and set the ride height/ weight balance to optimum. The only rub is then being able to reset the camber accordingly.

I'd have to differ about the assumption of a median airflow rate: road race cars operate in a 20mph to 140mph+ speed range. I've had a few cold drinks passed to me at Long Beach, Montreal, Lime Rock etc., where the hairpins are nearly a full stop in traffic. There has to be two MAFS, or else it's built into that airbox somehow.

I completely agree with you about the rear suspension, it looks like a pile of Lincoln Logs back there. Euclidean, even.

I did see the plumbing going up to what I assume is the dry sump tank, right rear corner of the engine bay. The rest I didn't try to follow.

The cliff notes I read on sequential gearbox were great, I'll have to go back to the Corvette site and see what in the hell is inside their transmission tunnel. No clue on that.
But if somebody was dying to have a five speed in their road car, that would be the way to do it. Along with a revised rear subframe to accept it.

Have you started tearing out any of your "25 kilos" of wiring yet? Unbelievable.

What do you suppose, $5 million R & D ? And they're two years late getting to the grid?
If the stone hasn't rolled, a few heads should.

 

The max power of the bored out engine from rocketsports is with the race intake manifolds (as you can see on the engine picture on their main website), and lots more modifications. It is more than just a bored out engine block, besides the dry sump design, they also increased the RPM (so light/strong piston/rods etc). Many things can be done on our engines, but unfortunately it becomes somewhat price, think for something like this in the 10’s of thousands. Nevertheless they have done a great job.

Regarding the 2 mafs, as the XKR has also 2, they might very well have 2 too. However you can just as well work with a MAP and fast UEGO sensors.

Andre.

 

Interesting yet informative thread ,thanks everyone
I would like to see Jaguar Racing Team in AMLS as well

 

Gee Andre, thanks for stopping by, even if it was just to point out the obvious. It sounds to me like your engine development program is well in advance of the Apex effort, at least when compared to these 2007 reports. If I were in your position, I would drive my XKR to their workshop to display it. Then I would begin negotiating a consulting contract to assist with their R & D. You've managed to match their HP numbers, even without a dry sump, and presumably you have negated the problems they have encountered with continued operation in high ambients.

Too bad you weren't at Donnington for the test day instead of that raggedy old D Type, you would have turned a few heads.

I'm disappointed to learn that I can't add 300 HP to the stock XJ8 engine in my stand just by boring it out. Here I was prepared to clear two weeks off my schedule and have a go with my electric drill and a cylinder hone.

The topic of fresh air intakes was discussed on RoadRash about two years ago, where I read about systems that were drawing dirty air (aerodynamically speaking) from the wheel wells. Bad ideas, and lots of them. So I walked outside and looked under a bonnet, and saw that a ram air setup could easily be constructed. Andre wrote at the time that he had already thought of the idea, but I never saw another word about it.

So I thought about where I would have mounted the air cleaners, and the idea came to mind about using twin MAFS. That permits alot of flexibility for the location of the components and ducting. The Apex laundry hose exemplar is their way of achieving this goal, although my thought was for something a little tidier. The question then became an ECM programming issue, as to whether the aggregate signals of two MAFS would require software changes or an additional interface for the ECM to correctly interpret the data. That is not within the scope of my ability to answer, so that's as far as I went. It was a much more practical and adaptable theory than re-engineering with alternative hardware as Andre's approach suggests.

It's nice to see that Jaguar reached the same conclusion for the factory 4.2 SR, XKR installation.

I started this thread because I continue to be interested in street car applications borrowed from the efforts of racing R & D. You're certainly correct about the cost of building high performance racing engines.The relic in the first photo below is the 5 Litre Chevy V8 variant we used in the 1982 Can Am Series. This particular unit is a V.D.S engine built by Franz Weiss, being prepped for installation in one of our competitor's cars.

You can learn alot from photos like this, even if the specific hardware has no direct application. Our engines were identical, built by Ryan Falconer, for about $50K a pop according to what I heard. The financial considerations of team operation were not within my job description. Neither was building or tuning the engines: in those ancient times and as today, teams are prohibited from dissecting any internal speed secrets built into a contract engine program.

Horsepower numbers were a bit guarded as well, as Ryno built these engines for more than one customer: among them was the Galles Racing Frissbee of Al Unser Jr. We probably didn't get the cream of the crop, but 520 off the dyno was the "happy horepower" range that was tossed about. From a pushrod Chevy 350, dry sumped. The mechanical fuel injection probably left a few horsepower on the floor of the dyno room, but it NEVER broke.

Electronically controlled injection was of course in use on street cars of that era, and I don't know, but I suspect it was regulated out of the series formula rules due to cost considerations. My job was just to plug in the engines and prep our race cars. The second photo below is the car we ran at the 1982 SCCA national championships, the #22 Ramsey Solution Frissbee driven by Rex Ramsey. In the pro Can Am series, Rex ate alot of dust, from Danny Sullivan and the late Al Holbert in addition to Little Al. We worked hard, with far less than spectacular results for the effort. And we learned some things...most often, we learned how much there was that we didn't know.

The last photo is a fuel stop during the race at Trois Riviere, Canada.This is the entry we used for all but one of the 1982 Can Am Series races, the Ramsey Solution Racing Lola T-530. I'm the guy on the left with the vent can. This crappy photo is the best I can post: I have a brilliant pit shot from another race, but no way at present to load it...there's alot for me to learn about computers, which is also of relevance to this thread.

If any of the keyboard racers had ever posted information about the Apex effort, or the U.S. Trans Am Series Jaguars, then it flew right by me. Almost none of the hobbyists who talk about high performance modifications actually know anything, and Andre has always presented himself as the most knowledgeable and proficient tuner of the lot. I have never expressed anything other than praise for his knowledge and research, and his posts were the only information I learned to trust among all the *******. Andre, it's high time you stopped writing to me as if I am one of the latter.

The twin screw modification of road going XKR/ XJR was never a practical idea in my mind from the day I first read about it. Only a few hobbyists like Andre have the resources... time, and money, and a very expensive car to start with as a platform...to undertake such a required series of modifications to complete. And accomplish them while still retaining acceptable reliability. It may not get you to Donnington, but it sure as hell better get you to work for your paycheck. Or home from the little rally with some rich pals.

So I started this thread when I became aware of the contemporary Jaguar Racing efforts, with an amazement that I had never heard a word about it. Then whiteSTR posts that the current US Trans Am race winning car is propelled by a normally aspirated stock block 4.2. That's something I want to learn about, and the Rocketsports site link I posted sure doesn't reveal many internal speed secrets. I noticed the intake when I saw the photo Andre, thank you very much. When I enlarge it, the clarity makes it difficult to examine exactly how the injection system is laid out. It looks very similar to the ancient Chevy, with a butterfly and injector in each stack. Perhaps I'll be able to take some better photos myself.

Performance modifications have never been a practical consideration for me on any of the stock fuel injected Jaguar engine variants I have built- straight 6, V12, or V8 N/A. The ECU/ ECM tuning always
seemed to be an obstacle that I could not address, and I no nothing about it. What sort of hardware
and software is required to achieve this capability? It is the first consideration in my mind, not
the last, before any significant performance enhancements can be achieved on a reliable road car engine.
Can anyone suggest another homework assignment for me on this subject?

I guess the XJ8 engine on my stand now won't be getting the two week hone job after all. But it would be a worthwhile effort at this point for me to examine the possibility of a new approach. These dead 4.0 litre engines have to be bored and sleeved. If posessing the capability to insure optimum fuelling requirements is at my disposal, then punching them out starts to sound like alot more practical idea during the course of a required rebuild. Perhaps lightweight Ford pistons or other non-custom components are adaptable, and at least modest horsepower gains could be made with a moderate additional investment. Anybody who can't build an improved exhaust system aft of the cats for $500.00 doesn't know what they are doing. So if there is a conservative and practial development program that could be implemented for normally aspirated Jaguar road cars, I'm all for it. There won't be many chances for me to be plugging in $50K race engines any time soon. And from what I read, and more importantly don't read, about the Apex results...well, let's just quote the Beatles and say, "Money can't but me love".

I now have learned the 4.2 litre Rocketsports engine, while perhaps even more radically modified, does deliver the goods. That's a place to look for any technology which may be adaptable for road car use. Perhaps none of the secrets built inside these engines are relevant, I don't know. Maybe I can learn a little when I have a picture of one dangling in the air, being prepped for installation at the racetrack.

Racing days are alot of fun, so I will be looking forward to enjoying some new ones. The five years I spent participating in motorsports was a long time ago, but the lessons I learned are valuable ones. All of the experienced and brilliant people I worked under had one thing in common: it was a question they shared, in recognition of their own abilities and how to improve them. I still try to remember to keep it in my toolbox. No matter how each day had ended, with their driver on the podium - or washing down a mouthful of dust- the question was always the same...

What did we learn today?


Andrew Bernstein
British Auto Care

 

I merely gave some info which wasn’t presented in the topic and it wasn’t directed to you, more for others to understand that it takes major work to make significant improvements.

That you suggest here I am pretentious is a bit out of line, but if it is your thing to judge people you don’t know, then who am I.

back to topic which I liked,

The challenge imho is to get cost effective/intelligent improvements, and for a NA car to get RAM air system would fall into that category depending on price. 2 MAFS is not simple, but I’ll bet you can find someone who knows about electronics/circuit boards to make from 2 signals 1 signal to the ECU.

For the XK8/R ram air is also relatively easy to do, and even without reverting back to 2 MAFs, not sure for a XJ8 though.

You might want to look what AM has done with the AMV8 to get more horses out of the jaguar NA engine (although not sure how much is comparable I have to admit), maybe some ideas could be carried over. I have only focused myself on my car, so don’t know much about NA cars. If the NA has the same sort of reserves as the SC, which might be very possible, then boring out the block with the new technique AM is using to get to 4.7 might be interesting to consider. Maybe it would still be more cost effective to have custom pistons etc made, even if the ones from AM could be used. The only area I would have a first concern would be the 5hp25 gearbox if you think about 4.0 cars.

Andre.

 

Andre,

Thank you for your suggestions, I will review the information and see if the processes and components are relevant to the sort of "stage 1" upgrade I am envisioning.

You're quite right about the ZF, I wouldn't dream that it could reliably handle anything in the neighborhood of a 20 % or greater increase in power. I'm looking for a little bang for the buck, not a big bang under the tunnel.

The first homework I have done has uncovered a company which provides hardware and software for ECM remapping. I have no clue as to whether this is a piggyback ECM installation, or whether they will have sufficient selectability of maps to rely upon. Hopefully, I will be hearing back from them. I found many fishermen, but no one else selling the fishing rods.

Andrew Bernstein

 

ok I stopped in to read a little since I need a break today from taxes...Andy we we gonna build under the koni challenges series and were working on what they would allow us to do to a NA XK. And since its patterned after a "STOCK" type class , we had to get alot approved..like viper, and Aston manual tranny, Intake mods, ecu, exhaust etc.. we needed 400bhp to even be competetive. And use of stock suspension although many things can be upgaded from a NA car to XKR spec in chassis and braking. They were really trying to work with us to get a Jag in the series....And it was becoming alot of research to put together a car without major aftermarket help from experianced company in the race realm as he posts, and pics show...Was gonna be more a grass roots dealership build with some factory help(here use this and you need this) there are alot of engineers that would really like to streach their legs out the back door....But all came down to funding...doesnt it all