Might be the wrong place to ask, but is there any off the shelf performance tweaks that can be done to the Stock 4.2 V8?

Had a Saab back in the day, stock BHP was 105, remap took it to 220 without the need to change brakes, exhaust diameter or clutch, could do up to 600 BHP if you were willing to change inlet manifold, outlet manifold, clutch, brakes, gearbox and more....

Wondered if there were any enhancements that could be done to begin with?

300BHP seems a little weak from a 4.2 V8, am assuming its tuned to keep Californians and Polarbears happy?

 

>off the shelf performance tweaks that can be done to the Stock 4.2 V8?
Unfortunately, not many (if any at all). The 4.2 wasn't the performance package it was for a serenely riding executive class car. Sorry
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Jaguar - it's not an automobile, it's a Motorcar
Current: '15 XF (X250) Portfolio AWD 3.0 (it's aubergine...)
2018 JCNA Class N Slalom 2nd-Place
Past B: '08 S-Type 4.2 "Satin Edition" (250.06 whp / 259.67 torque)
2015 JCNA Class M Slalom Champion
Past A: '05 X-Type 3.0/auto Jaguar Racing Green

 

The SC version would be the obvious one to get them. Best idea would be change to the SC first.

I have huge difficulty believing those HP gains mentioned but regardless you will not get them easily or at all with the actual car you have.

 

Most gains in tunes come from cranked up boost on forced induction engines. The NA V8 should be plenty but the car it has to push around is way too heavy. With the artificially low speed limits there is nowhere to use SC power anyway, and with the comfort suspension the NA makes much more sense as a daily driver. Just delete the mufflers and waft away.

 

• Stage 1 - tell the computer to allow the Low Pressure Turbo to spin to Full Pressure and remove the flat spot at the RPM the noise test is performed at.
  • All that's needed is a laptop and a home made PCB and crocodile clips, the mapping from the internet
  • this is what i had done, the 2.0 LPT would wheel spin from the traffic lights with a free spinning FPT and an improved mapping - gave better MPG too.
• Stage 6 - Swap Header pipe and full exhaust system to 3" bore, swap inlet manifolds, swap cylinder head to one that's been gas flowed and ported, boost mapping in ECU to max output, Swap Clutch and gearbox, swap brakes (pads/calipers/discs), swap injectors, swap plugs, swap Turbo for a race turbo (not road legal..... but shhhhh) and then swap the coil springs and shocks.
  • its v v expensive, i only knew of 2 people who did it and the end result was something of pure magic.

there are obviously stage's 2 - 5 i missed where do do some of the tweaks - stage 3 only needs 3" bore exhaust manifold but regular 2" system, and a different mapping...

Not looking for anything amazing, just felt 300 bhp from a 4.2 V8 was a little sedate - was assuming the reason was emissions and noise limits in California?

I do love my car, and the reason for not getting the SC was because:
1) none available to buy
2) my first Jag
3) after my car accident and insurance payout etc, I could only afford the one I bought, I was about $3000 out of pocket from my Range Rover to the Jag, but I like it.

Perhaps when my injury money comes - i could look at upgrading to the SC or the Premium Lux at a minimum.

 

Saab guy here..

Yes after the turbo Saab you needed to go SC (or turbo now) Jag I knew moving out of Saabs ( since they are a dead brand )


I got a 3.0SC and tuned it from 340 to 415 HP. and its very nice. Not as much fun as spanking someone with a Swedish 4cyl but the Jag goes and I like it..

 

Big Smiles remembering the look on a Subaru Impreza drivers face when i left him at the lights....... ah, RIP Saab, you are sadly missed >:0(

I had the Stock 95 2.0 i4 Low Pressure Turbo, few beers and an afternoon at a mates with the mappings and the Circuit Board - Specs online to make, and Voilla - Subaru Crusher on the inside whilst looking like a mild mannered father of 2.4 children from the outside - a bonus was a secret menu that was now accessible via the display panel and buttons - and we programmed it to read "Hello Peter" when you turned it on and "Goodbye Peter" when you turned it off!

Was simply wondering if anyone had any success tinkering with the stock Jags?