I have itched again closer to the 700 HP (dyno'd 585 rwhp), here is the thread with more details:
https://www.jaguarforums.com/forum/j...700-hp-154721/

 

Hello everyone!

I'm new in this forum and to be honest my interest in Jag's started mainly because of this thread... I've always been into cars where its not immediately noticeable that they are fast.. The previous car I built and tuned was an old Peugeot 505 2.2l Turbo engine with 350hp...

For this post I'm not sure is this the right place but lets try....

So after reading this thread I had to go and buy a stock 2003 STR and luckily I found one guite easily. Here in Finland where I live there are not many STR's.. One guy told me that there are only 64 registered ones so I'm happy that now I got in my own in my garage waiting for going to the dyno on thursday...

What I will be aiming to do this year:
- Get 600 - 650 ehp out from the engine
-- Thinking even pushing it further with E85 if the internals can handle higher power? With E85 you can go higher with your boost and spark advance since it handles way better knocking due to its high octane figures..
- Quaife differential, or are there any other options?
- Exedy gearbox internals whenever its necessary, hopefully not yet this year... Probably in this gearbox matter I will go the hardest way: Brake the existing one and then replace the gearbox after total destruction with better internals...
- Lowering springs and some other small things...

Since the car is totally new for me I have some questions:
- How does the existing intercooler system work and what is the performace of the system? (luckily its always cold in Finland)
- Has anybody installed a DTA, Megasquirt or Hestec engine management? This would allow to get rid of the MAF and use easily bigger TB's and of course optimize the spark and fuel to the selected boost level... > More advance > more power
- What are the limits of the engine internals? Has anyone broken pistos, connection rods or crank shafts? How about the bearings?
- Has anyone converted STR to E85? What changes are needed to the fuel system to be able to handle E85? OF course bigger injectors but meaning in general the erosion the fuel can make...
- How capable is the stock exhaust and cats?

I'm very grateful for your answers and I'm following this thread closely. Hopefully after getting familiar with my own car I could help somehow i getting more out of these cars..

-Tama

 

Avos where'd you source a 4.8l for your STR? I had read somewhere a long time ago, about stroker/bore kits for the 4.2l but can't seem to find them online anymore.

 

Arden still has some old stock left, they have a 4.5 stroker kit that includes the crank and rods for about 3900 euros. That is overhere a fair price.

I went a more riskier path by boring out the engine, but use the stock rods and crank. I have taken this risk triggered due to budget constraints and reasoning that I only use it for street driving. This was already more expensive than the stroker kit, but have now also 4.8 ltr.

 

I think I have just hit 700 HP
https://www.jaguarforums.com/forum/j...1/#post1380032

 

Wow! Congrats! That car is a real beast!

 

I have a 2010 XKR. DO YOU HAVE ANYTHING. For her to boost her HP

 

I have played with that idea, but the costs would be very high to develop a TS to fit and with the right tune/pulley’s you already can get some very good power from these 5.0 SC engines, as their TVS supercharger is already much more efficient than the old Eaton roots one.

 

Yah those TVS chargers are pretty efficient. We've been playing with them compared to the twin screws of similar size on a few ford engines. They tend to be more efficient down low compared to the twin screw and ultimately giving up a bit top end. Definitely not worth the cost of a swap. Intake mods, a tune and pulley. Unsure if they have any Throttle body upgrades for the newer 5.0 SC motors but that would help as well.


As far as Andres 4.2 STR and XJR kit its top notch!

 

5.0 TB can be Maxbored from 83mm to 86.5mm.

 

OK, how much does the kit cost? I am going to add the Quaife diff., are there any deals on those around? Like I said on my crash post I'm in 16K (US) before the bending of the rad support and headlamps and frame shop plus bumper cover (used cost, $1400. US). So, I'm in for a penny and a pound!

 

A TS project including a quaife diff install... depending on who does the labour, this is going to run you $15k or more easy....

 

Is this thread still alive? I'd love to order the Stage II kit for my XJR X308.

 

He doesn't offer an X308 kit from what I can tell...

 

The stage II 4.0 XKR and XJR kits are actually the same, so I do have a kit for the x308 as well. Pm is send to ahmedalalousi.

 

Hi,
after 2 and a bit years I finally have XJR running again - completely different set up to what it was, now has Nissan 550cc injectors - which are not responding well to the Abaco MAF - their software is not loading on my new lap top, their website is not available - but their junk still appears at Summitt racing and a few other sites, does anyone have any idea how I can get hold of them.
Cheers,
DC

 

I have been asked to be more respectful to my Abaco MAF -


I have changed my opinion of it totally as well - I used to sit and write the calibration and download it to the unit.
I have discovered I can move 1 or multiple sliders and make any adjustment while the car is connected and running - after about 2 seconds you hear the changes, (even the very subtle ones) in the engine and see them on the data logging - I am actually very impressed. It completely changes the tuning game with this MAF -
I wish I had known this 3 years ago

 

After long thinking I have now decided to stop making Twin-Screw kits for the coming time.

Many reasons have played a role in this decision; The amount of time required to make a kit; risks in buying the expensive parts where things could go wrong (so far all was ok, so that was a bit of luck), with a very small margin for me where there is just no room to cover for events; suppliers unhappy about low volumes (so prices keep increasing), and the low amount of kits (and diversity of kit models) just do not offer any room for me to generate a stock of parts.

Although I have enjoyed, and still do, working on these kits, time has come to make this decision.

Of course I will provide my full support for everyone that has my kit, that will stay as long as I can, and maybe (maybe) in the future I might continue again, but I just can’t keep the costs as low as I have done this far.

So that’s it for now, if there is any change in plans in the future I’ll update this thread of course.

 

Very sad to hear that. You have to do what makes sense for you. Guess my next upgrade will be a TVS 2.3 Coyote Motor from a Mustang. Guess ill have to re-engineer the rear suspension so it doesn't use the half shaft as the upper link.

 

Am really sorry, but I do wish you the best with making a kit for your own, there is a lot of fun creating something yourself as well.

Maybe if someone sells their car, and reverts them back to original, a 2nd hand kit could become available (these kits will last). Chances are small to be honest, as most owners do cherish their cars so are more keepers. Nevertheless if I hear about it I will mention it here.

It was a unique project for me and a unique product as well. So herewith I want to thank everyone who bought a kit and gave their trust!