Jaguar XJS progress.

APEowner said:

I'm looking forward to this build.  As far as which direction it should go is concerned I'd go with whichever will allow you to run the most affordable tires. I want to see this on the track as often as possible and tire cost is likely to be the most significant budget restriction.

My last Jaguar the tires were well down on costs. I used Dunlop Vintage race tires and I never ever wore them out. They would get harder and harder costing me more time per lap until the money tree allowed me to buy new ones. 
    The most expensive item was and still is entry Fees.  Currently about $500 per event. It pretty much doesn't matter if it's a Champcar, LeMons, SCCA, or Vintage race.  Anytime I go wheel to wheel that's roughly what it costs. 
     Of course there is travel costs which used to limit me to one outside my area event a year. I used to Iron man those.  Drive there virtually non stop. Stopping  only for food, fuel, and bathroom. If the event was more than 24 hours away, any rest I got was at a roadside rest stop in my tow vehicle.   Then I'd camp at the track and head home after loading up.  
The deal with Champcar and Lemons is you get more track time.   At my age that's not a good thing.  I come in after a 30 minute Vintage  event completely worn out. Happy!, but exhausted.  I've got 10-12 laps to pass those I can pass  and hold off those who would pass me. It's very much like multi level chess at high speed. 
 LeMons/Champcar  is more about consistency and smoothness.  At least the endurance events I entered.  

How many minutes will it run on a tank of fuel? Stock tank is about 20 gallons.

In reply to frenchyd :

Group A -- unflaired.  Unless you can't get enough rubber under one.

I think the XJ-S, especially with the Euro headlights, is one of the best looking cars of the 1970s . . . I'd keep it close to that aesthetic.

sergio said:

How many minutes will it run on a tank of fuel? Stock tank is about 20 gallons.

24 gallons. 
How many minutes?   I really don't have a clue.  My Black Jack used to average 9 mpg around Elkhart Lake and a tankful would last the whole event.  ( of coarse it was a 48 gallon tank ). 
     Based on that, I'm guessing around 6 mpg.   That's 35 laps. So somewhere around 70 minutes. 
That's longer than 2 of the three drivers can drive without making mistakes. 

ZOO (Forum Supporter) said:

In reply to frenchyd :

Group A -- unflaired.  Unless you can't get enough rubber under one.

I think the XJ-S, especially with the Euro headlights, is one of the best looking cars of the 1970s . . . I'd keep it close to that aesthetic.

Tom Walkinshaw was able to get 17x9 rims in the front and 17x13 rims in the rear.  
I think he did it by raising the car up and putting 900 in/pd  springs in.  (Basically very little compliance). 

Just so you know, lemons and champcar fees are higher than that.  However, Im assuming you mean splitting them amongst a few drivers.

Fuel, brakes, and tires are gonna be expensive for this beast.  I'd bet you go through about 12 or 13 gph.   That is roughly 40 to 65$ per hour in fuel.  A lemons race will cost you about $700 in fuel as an educated guess.

Tires will probably last 1 or 2 events at about 1k$ per set.

Brake pads I would imagine are about 300$ per full set.

That's about 2k per race in consumables as an educated guess.  That also assumes you would like to try to win.

yupididit said:

IIn reply to frenchyd :

Are you going to fender roll it or some other type of flares? I'm certainly interested in how yours turn out because I want to do flares on my XJS.

I'm thinking I'll cut a radius big enough to fit the tires. Then start a lip, move the piece I cut out enough to clear the tire .  I'll then make a cardboard pattern to fill the space between.    Once the pattern is made I'll duplicate it in steel and using the English wheel make a smooth flair that won't take much filler. 
    Once done, I'll weigh  the resulting fender and decide if it will be a pattern for a fiberglass fender.   
in rough terms fiberglass weighs 1/2 of what steel does and carbon fiber is 1/2 of that. 
   If the fender weighs 20 pounds the weight savings is worth the time.  If it's 7 pounds probably not. 

wvumtnbkr said:

Just so you know, lemons and champcar fees are higher than that.  However, Im assuming you mean splitting them amongst a few drivers.

 

Fuel, brakes, and tires are gonna be expensive for this beast.  I'd bet you go through about 12 or 13 gph.   That is roughly 40 to 65$ per hour in fuel.  A lemons race will cost you about $700 in fuel as an educated guess.

 

Tires will probably last 1 or 2 events at about 1k$ per set.

 

Brake pads I would imagine are about 300$ per full set.

 

That's about 2k per race in consumables as an educated guess.  That also assumes you would like to try to win.

Thanks for those numbers. It gives me good numbers to work on.  
  My rough calculation says about 70 minutes per tank (24 gallons)  that's $50 a tank.  Say $600 a 7 hr double header.  So we aren't that far apart. 
   Figure $500 per driver in consumables. 

So while used slicks and wide 15's may be a cheap way to fill the flares for vintage racing, what's the 'street tire' plan for Champ/Lemons?

I need at least two more partner/drivers to consider  a Champcar, LeMons. Run.  Assuming that happens  I can buy Corvette Camaro wheels and tires. ( they have the same bolt pattern ).  Probably something around 18X9 rim and probably the new Continental/Hoosier tire to fit ( assuming good reports in tests) 

obsolete said:

I vote maximum flares. When I think of a low-budget Jaguar XJS race car, this is the benchmark:

I vote this except all 12 pipes in a straight line down the middle of the hood. Like a mohawk. 

In reply to frenchyd :

Would the offset (backspace) on common (affordable) Corvette/Camaro wheels be suitable to the flared XJS fitment?

It really depends on the wheel. Back spacing of 5" is about perfect but there is some allowance depending on tire used, and spacer?  
     It all depends on what group SVRA & VSCDA  will allow me in. Group 6 requires stock fenders.   
  My stock wheels would allow up to a 255/60  DOT tire. Tires like that would last a very long time but wouldn't have as much traction as a proper Vintage race tire. 

Robbie (Forum Supporter) said:

obsolete said:

I vote maximum flares. When I think of a low-budget Jaguar XJS race car, this is the benchmark:

I vote this except all 12 pipes in a straight line down the middle of the hood. Like a mohawk. 

I think those pipes were just for looks, so, sure, why not?

There's no way I'm going to buy/regret a 1980s XJS, but if anyone wants to build a 'Frenchyd Replica', I could go check this out and hold it for you: https://www.facebook.com/marketplace/item/338167477875687

In reply to AAZCD (Forum Supporter) :

It's eligible for a lot of Vintage race clubs.  Champ car and LeMons. 
    The one thing you rarely have to worry about is the engine.  Talk about overbuilt!!!!  
   While the fuel injection is very hard to modify  Jaguar made V12's  with carburetors  from 1971-1974.  Used in both the XKE and the Sedan. That engine is very simple to work on with carbs. 
   Don't worry about the wiring.   I just chop it up and throw it away. It's just as easy to wire as a V8.

 I sold my interior and got the whole price I paid for the car. ( and then some). 

    400 horsepower will cost you very little to get to.  I figure I'll go through the whole engine and regrind the cams and be at about $500.  That's not that unusual. The silly money people pay to have someone rebuild the V12 is foolish. 
    Swapping a manual transmission on a V12 is almost a bolt on since the alignment dowels are located in the same spot as Chevy's. Get a good Chevy transmission, spend an easy morning making the adaptor ( requires ability to drill holes in aluminum and tap threads).  Oops,  cut it out when finished.  I use my Jig saw or band saw.  The rest is normal stuff. 

Dirtydog (Forum Supporter) said:

The car looks to be in pretty good shape.  Now, if you aren't doing a Summer School run, you can devote some serious time to this build.  Following with interest.

Summer school is just in the morning so I should be home by 1:00 with plenty of time to do the Honeydo list and still get some work done on the car. 

Dangit, Frenchy, now you've got my looking for v12 jags in my neck of the woods.  

No...must work on 3.8s...4 door saloon better family car...

I think you should do up your XJS in tribute livery to your own Blackjack.

In reply to volvoclearinghouse :

Toss a V12 in your Plymford 

   I regularly see rusty non running V12's   in your neck of the woods. Those are good. Few wear out, rather the EFI stops working and they are parked. The engine itself is good. You can either fix the wire/ crack rubber hose/sensor. Or replace it with carbs from the early ones. 

Man.  A four door, non-rusty one.

In reply to volvoclearinghouse :

A little overpriced but that could be a pretty car. Just need to get rid of the v12 lol

In reply to yupididit :

That's the 6 litre HE V12, if wikipedia is correct.  300+ HP, stock, and a 6l80E transmission to boot.  The fuel injection is supposedly not horrible on these later cars, either.  I bet a little fiddling and it'd be a driver.  Based on the ad, I also bet there's more than a little wiggle room in that price. 

In reply to volvoclearinghouse :

Once Ford bought Jaguar their development money increased dramatically and for a while Jaguar was the most reliable car. 
  Yes, it's not only reliable but some of the parts are from Fords parts bin.  
    The one negative is the crankshaft. Instead of the Forged EN 40 steel one Ford  had the last batch made in Germany from Sintered Iron. Much better than cast Iron but not as Bulletproof   for racing.  
 

Oops!   It might be a Forged crankshaft. That's right about the last of the forgings and  first of the Sintered Iron. 

In reply to volvoclearinghouse :

4L80e transmission. Don't think gm was doing 6 speed autos back then.

In reply to yupididit :

No Jaguar had a 3 spd with the TH400 then went to the 4speed  with the 4L80e