Warrjon thanks for the link! Gave me some good pointers

 

A cross-ram style intake works well on most American V shaped motors, but, due to the placement of the plugs and distributor on the Jag V12, it will be a nightmare to check or change the plugs, something you will likely be doing a lot of as you tune this engine to find the sweet spot. I assume that, like me, you are going to ditch the distributor, and go with a modern coil-on-plug type setup, so, stock distributor placement really wont be a factor in your intake design.

 

the whole science between a long runner is it forces a lot of air to start moving and keeps the velocity up so when the valve opens air is forces in creating a mild supercharging affect

 

your dead on calvin! thats another property of them haha too much flow it will run like crude to little it wont go anywhere at all. an engine is an air pump everything has too sing too a certain tune if you will, if one things of the whole choir is useless! like I said its all mathematics If some one wants me too ill go into it but its a long winded discussion .

 

How To Calculate Muffler Size and Exhaust Pipe Diameter | Exhaust Videos this is close too what Im speaking of

 

Calculation of exhaust system

 

Primary Header Tube Length and Diameter Calculator

 

what exactly is your budget on this build?

i think for what you want you're going to want to up the displacement and run a pro charger or two. if you think about it in terms of airflow, 1.8 to 2.2 hp per cfm is the rule of thumb, so youre going to need to make atleast 450 cfm from the superchargers.

 

Errr budget?? whats that mean haha. no limit just a goal I have the procharger already but the car is going too get some much needed tlc afterr its neglect. Replace all the seals on the windows an doors etc. it sat for awhile outside how long is undisclosed but its slowy coming back too its glory!

 

What thickness spacer would I need for the front wheels using the BMW wheels for the XJS? -Or do I?

 

This thread needs an update. Winter is over.

 

GregH they will fit but the center bore is incorrect for it I can't pull the numbers out of my head at the moment. Yes I do believe an update is needed. I sold the procharger the car has been ooff and on the lift for basic stuff brakes, suspension minor rust repair working too many hours lately car has been sitting on the back burner I'm liquidating a few of my projects too put money into this one . I had too use my previous savings because I had a women pull out intront of me totaled my daily driver might end up with some $$$ from that incident. Now back into performance stuff how does one go about beefing up the suspension on these cars what's the spring rated at? I suppose it would have too be custom or swapped from a simular vehicle?