Ok since there are alot of new and old guys getting more and more interested in making great power out of our cars so lets start listing what you think is the best power upgrades for these cars??

So far this is what I think makes a good difference I think these cars are easily capable of 420 to 450 rwhp without the addition of a twin screw. Now we just need to figure out how to do so.

04-08 Gen 5 blower
crank pulley upgrade
tune
ported n polished intake manny
ported TB

things I am thinking that would help performance


weight reduction (hidden weight reduction so as to keep all stock looking appearance)
rear end gear changed 3.50 range would be great
3.5 in aluminum intake mandrel bent for better flow
larger mannys or short tube headers with high flow cats and 2.5 down pipes with xpipe all the way out through magnaflows
better designed camshafts
ported and polished heads
better intercooling system

 

when I had my SC rebuilt they put in the 5th gen lobes, I couldn't detect any difference but due to the SC overhaul my car was out of service for a few months. In cooperation with all of those other things it could be a noticeable improvement.

I definitely agree that the intercooler could use some help, the fact that it has pipes that share/exchange coolant with the engine is silly to me. A separate intercooler coolant system would definitely be good in my opinion.

 

The 5th gen blower may not add a huge amount but I would be willing to bet it makes a lil more with the same boost level but even 20rwhp is almost impossible to feel I noticed a big difference in how much quicker the boost comes on and doesnt bleed off so much at higher rpms.

 

This has been discussed before, and separating the systems is not necessary. They're only connected by one hose/pipe, and there is no circulation between the two systems, which is why they have separate pumps. Only purpose of this connection is to avoid having two expansion tanks. Pretty clever IMHO.

A larger intercooler radiator would still be very useful together with an upgraded pump. Powerhouse and some other (eurotoys?) sell a bigger radiator, but it's just a thicker version of the original. There have been speculations that it restricts air flow more, and only helps as it increases the capacity of the system. A radiator with a larger surface area would be more beneficial if that is true. Would be interesting to see some numbers on this.

Another thing that should bring more power on a boosted engine is E85. It cools the air charge more than regular gas and it's more knock-resistant. This would probably need larger injectors (available from Buckhead for about $1300), but as no-one seems to have specs on the stock injectors, it's hard to say for sure.

 

Local news! Youth jailed for 140 KPH drag racing another car (100K zone) = X308 up to 250 KPH.. what the hell do I do with MORE power here?? But if you must,good luck with it!
Neil.

 

It adds safety to overtaking, as you'll spend less time on the opposite lane.

 

First tuning, then supercharger, then 2011 powertrain. Why wouldn't you just perform a friggin LS swap and have access to power upgrades at your fingertips for a fraction of the cost? I would think the ZF trans would self destruct and our motors would melt at 450hp. Lol.

 

XJR transmission is from Mercedes, not from ZF. Dunno what's the melting point of this tranny, but it's definitely above 600hp.

 

As I am still learning these cars I am not sure how much I can add.

With the same blower on a 4.6 Ford V8 you hit a wall around 470rwhp and thats through a T56 with much less parasitic drain and through a dedicated intercooling system that is MUCH more efficient compared to the Jags and can keep IATs at ambient or lower. That is also spooling the blower to 13-14 PSI.

E85 is an idea but wont help enough IMHO. Again in the Mustang world there are people that use it on the twin screw upgrades. With the twin screw, tune and fuel upgrades only they can make over 700 RWHP on E85. If it were pump gas they would melt the 7&8 pistons. LOL

 

That's right, the XJR has the better transmission. I didn't think these motors could push much more than 400hp. How much does it cost to achieve 450hp in these, $8k?

 

450 at the crank or wheels? At the crank it should just take a tune, pulley, exhaust and maybe an intake although the stock air box does not look very restrictive. All that will run you $1000-$1500.
At the wheels..... well thats a different story. $8000 is prolly close cause you need to port and polish and change to the newer blower etc etc.

 

I was referring to at the wheels. What's it cost to slap in a LS variant SBC motor and trans? $8k?

 

Eurotoys' twin-screw kit is $6500 plus installation. I'd think it should get you close to 450rwhp..?

 

Maybe 400rwhp, certainly not much more.

 

Actually, the stock intake is pretty restrictive. I gained about 30hp with a full intake system. (throttle body forward)

 

Mech wheres your sense of adventure any lame retard can remove what makes a jag a jag and put in an LSX series motor considering they are my mainstream of my car tuning buisness it would be super easy I have a LS7 powered camaro making 560 rwhp NA on 91 octane at 5000 ft above sea level uncorrected. I have an 02 trans am with a LQ9 built 408 running a custom single turbo system making over a 1000rwhp. yes its cake and easy in fact im a great tuner with EFI live and HP tuners but thats the whole thing. I want to keep this jag a JAG meaning it has a JAG drivetrain and take it as far as i can. I still think other pioneers before and gotten their hands dirty. Im sorry i have just scratched the surface and sad tht the intake elbow can be improved as much as I did and made such a BIG difference and thats just the beginning. make the intercooler system better will yield huge returns, We have yet to see what P&P the heads, headers, camshafts, bigger TB, an such will do. I can say tht I think a solid 420 rwhp without a twin screw is possible i may be wrong but hell its fun to try.

 

I heard tht the intake system sucks and if my buddy gets free we are making a nice mandrel 3in or 3.5in system all the way and then since I relocated the window washer the filter would be perfect right behind the headlights. We will also make a heat shield and seal it to the hood with a very large cone filter.

 

Exactly what I did:

 

I wasnt saying the tubing didnt look restrictive because with the bends and flat spot it is but the air box itself does not seem to be the bottle neck for anything around 400 rwhp.

 

Also I look at the cars online where they have upper and lower pulleys, ported Eaton and exhaust and they are all only doing 355-380 rwhp. Now that seems to be on a stock tune so I guess on a cool day with low humidity and a tune that 420ish seems obtainable with the porting work you have done. Eeking out that last 40 hp is always the hardest. LOL