ok,

Here is the first photos of my project Jaguar 3.8s. The car will be upgraded with a 450-460 horsepower aluminum block and aluminum head fuel injected LS1 5.3 liter V8 with automatic transmission. This will be a daily driver equiped with a crazy mobile office system.

Most 3.8s and MKII cars that I have seen after doing extensive searches have kept to the stock rims diameter and I have only seen one with larger diameter rims with 225 wide tires but they cut the rear fenders in order to do that. I wanted my 3.8s to remain stock on the outside and be more of a sleeper with modern amenities, power, handling, etc.

We measured the wheel wells to confirm what type of offset rims could be used to stuff the largest tires that still could be rotated. The 3.8s can take a 17" rim that is 8.5" wide if you use a 5.75 offset to in the inside. That rim will be able to take a 17" x 245 wide x 40 series tires with no rubbing at all. To ensure no rubbing on hard cornering we are rolling the fender lips and change a couple of the inner fender bolts to give maximum clearance.

To handle the increased torque and power we have taken the rear basket that holds the brakes and rear end and added square bracing that was welded to give added strength. Also the control arms had metal plates welded to strengthen them as well. We then painted all of those parts with "Pour 15" chasis coating which is one of the best coatings to prevent any rust. Prior to the Pour 15 we use the Por 15 metal prep which provides a nickle oxide coating prior to the chasis black coating. The entire under carriage and engine bay will be coated in the manner.





















We are upgrading the shocks to adjustable shocks and changing the set up to adjustable coil overs so that we can change the height to the precise height to provide the car with the best handling with full height springs.

Anyway this is the first report on the 3.8s build, we will be moving to the front suspension shortly and mounting the powerful V8 soon!

 

Here are a few more pics of the rear suspension which should be done by early next week and we can move to the front suspension.

 

keep the pics comeing,
nice job,

 

you can use V12 E vented discs on the rear.

 

I initially thought it would be cool to have vented bigger brakes in the rear as well but since the fronts represent most of the braking for any car I am just going to upgrade the fronts to 4 piston vented Wilwood brakes in the front.

How much have you seen the V12 Etype rear brakes go for? I have not seen any on e-bay?

 

After investigating the rear suspension design and what has been proven the one upgrade many of you should consider for any independent rear suspension Jag that you just want to drive hard regardless of the power plant would be the "Watts Linkage" that eliminates most of all of the issues of hard acceleration and/or the same situation combined with more horsepower. The kit is not that expensive and will enable you to drive it really hard without worrying about the hub carrier cracking over time, etc.

Check out this video
http://img121.imageshack.us/img121/434/picture001.mp4

I think this upgrade is a good choice for any Jaguar with the independent rear suspension and with that you can upgrade your power safely to about 500 HP with no suspension worries. I would recommend to strengthen the basket and control arms as I did. If you do not have a shop to do the welding Nick at Acton customs can sell you those parts already fabricated.


Now if you have say a lot more HP, say about 650+ the same maker of the Watts Linkage, Nick at Acton Custom Enterprises can sell you an additional brace that Cobra owners use for bigger horsepower applications. He also can provide tubular control arms and other parts to replace the stock Jaguar parts if you want do a lot more and have more suspension adjustability.
Acton Custom Enterprises, LLC.
33 Wildwood Drive
Holderness, NH 03245
(603) 279-0241 Shop

It is pretty amazing to see how radical some of the Cobra owners have taken the already good Jag suspension to incredibly new levels of performance!

 

What is the part number are the QA shocks and what springs p/n. I don't know if I'll want the stiff springs as you have that extra office equip weight.

 

Steve,

I will go next week and get that info and post it here. The rear springs are increased a bit but I do not think too much we based the increase on assuming about an extra 100 lbs as a guess in the rear for the large office lazer jet, wire binding equipment, dual batteries, high speed scanner, and a microwave/frig. yet we still wanted a smooth ride not a harsh sports car rides since it will be daily driver for me.

 

I need to check with the shop for part numbers as we put it together by measuring the requirements as this was all tailored to the car NOT a stock retrofit kit. The stock springs are I believe 180lbs and we used 200lb springs to give it a bit more stiffness for the weight but not much as we really did not want to make it a rough ride but rather a luxury performance ride.

 

I'd like to lower the front of my 420 an inch or so, would you say I could chop the spring, or would I need to buy a special one.

 

For any car chopping the spring is never a good idea as you are loosing travel in the suspension. Lowering a car is great for improved handling but you want full travel of the suspension. To me I would recommend to change to adjustable coil overs which you can then raise or lower the car yet the travel is not compromized. It is not that difficult or expensive to have it done and it will be well worth the upgrade for performance and looks. If you or a good shop measures it many non Jag adjustable coil overs will work for a Jag, like Chevy and others but you need to know what you are measuring and know what you are doing. There are brands made specifically for Jags as well.

The next alternative but I never bothered looking to see if it was available for Jags is aftermarket stiffer slightly shorter springs made for the car. This is NOT a great option as you are still reducing travel but if they are done decent they will only lower the car a small amount say 1/2 inch to 3/4".

 

Thanks for the reply, I will see if I can find some that will fit.

Another (stupid-ish) question:
Is it safe to say my handling sucks because my shocks are old and soft? You can bounce the car by stepping on the front bumper.

I dont take many sharp turns but when I do the car tends to want to stay turning, and I have to correct the steering.

 

You definately need to update the shocks and suspension. While these are old cars they were way ahead of their time so it is a great design to improve on. They can be great handling cars that with a little work rival new cars with modern suspensions. I would take it easy until you find out which option you want to utilize to upgrade it.

 

Hey is it only necessary to add the square tubing to the back side of the IRS cage? I noticed you didn't do the front (pinion) side. Didn't know if this was due to clearance issues maybe?

 

Some of the Cobra's that use our Jag rear ends have made full billet cages but thus far the extra bracing seems to be holding up just fine. I was not able to mount the watts linkage due to tire clearance issues. Right now I am awaiting custom spindles for the front to improve the handling and allow for longer front coil over springs.

 

Are you just getting "drop" spindles made up?

 

Yes I am getting custom drop spindles and steering arms from Michigan Metal Works, the car already has custom lower A-arms.