Thanks for the lesson Gt42R. You made sense in simplest terms.

 

Why did Arden, Paramount Performance, and private STR owners reveal their 500 chp STR's with intake, pulley, exhaust, and ECU mods? Two years ago I communicated with a UK STR owner on his Youtube vid of his 475 chp STR on the dyno. We've done all the mods he has except for his Paramount Performance ECU tune.

 

If there we ever to be some sort of national GTG, I will gladly buy you a replacement beer.

 

GT42R is right-on-the-money with his explanation of Tq / Hp. and I'm 100% in agreement with his assessment of claims that aren't backed-up with numbers.
Many of these mods that are easily accessible for us (STR Owners) are not necessarily designed to work together as a "kit" or various stages of the same end-result. We do need a "tune" in order for us to see the maximum benefit from those various bolt-ons. However: I'm not convinced that our adaptive / smart ECU isn;t already capable of "learning" our modded motor and optimizing it for us, at LEAST as effectively as an out-of-the-box tune, that doesn't take into consideration individual driving habits, altitude, fuel quality, etc etc etc.

I'd love to believe it, But I won't until I see someone do what is VERY simple to do; a before and after Dyno, with no other changes but the tune.

Until then, they're like the fat-kid in 6th grade that everyone assumed was tough 'cuz he said so..... and then one day the skinny 5th grade girl kicked his A$$.... Proof's in the puddin' fellers.

 

Mcjaguar, I'll soon prove via pre/post dyno that our mods, along with an ECU tune will belt out near 500 chp. cbharley, via Stainless Works, will test mule his STR for long tube headers. This'll put us over the 500 chp mark. Mark my words!

 

chp is an estimate, rwhp is what counts.

Arden sells a kit with 80 chp more power (not for the str, but the 4.2 xjr, same engine/intake setup), it consists of all you mention, and stroking the engine to 4.5 ltr (for just $40.000). That's not 500chp

Haven't seen anything from Paramount that comes close either, nor from anyone else.

I would suggest to make a base tune now with what you have already, and next ones after mods.

 

Hi Avos. As mentioned: A bloak from the UK made a Youtube vid of his STR on the dyno, posting 475 chp. After the intake manifold gasket swap I'll do pre/post ECU tune dyno runs. My first and only dyno run (dyno shop sent by e-mail, then lost) revealed on or about 350 rwhp. I drove 40 miles to the dyno shop, so she was hot, neccesitating the placing of bags of ice on the charge coolers prior to runs. There were also small undetected vaccume leeks at the time. I'm praying that with the repairs and the recent addition of the Mina intake, that at least 380 rwhp is realized.

 

Without any info (dyno slip with a/f ratio and rwhp) one can say anything, even a bloke from the UK.

Just dyno, so you know where it’s now.

Small vacuum leaks wouldn't have a big influence, but better of course to always make sure it’s in a good state.

Never used any tricks like ice or so, just let the engine run on the dyno before and between runs for cooling down and make sure the cooling fans of the dyno shop are setup right. This is how I always cool it which is also similar to street driving. You could turn on the airco, so the engine fan is operating as well, which will help airflow over the intercooler radiator.

Best to at least do 3 runs, so you get a good average, and don't forget to measure the a/f ratio and check your tires pressure.

 

Thanks Avos. What tire pressure do you suggest during the dyno runs? 35 lbs. is what I use for mostly highway driving.

 

Am using the same pressure, important is that you have the same pressure between runs, it can have a noticeable influence.

 

Before I begin to think I'm in a time-warp here, did not Paramount go into liquidation? And I seem to remember that Paramount software was acquired by a company that denied any association with ECU Tuning. Am I mistaken?

 

Robin, last year Paramount went into bankrupcy.

 

ETG has a tune for the 4.2L SC but it only lists the XF and the XJR/XKR.

They seem to have a very good tune for the 5.0L SC as there is an XFR running 11.9 sec 1/4 mile times right now on the forum. This is with a pulley too but still very impressive numbers.

Why would this not work for the S Type 4.2L SC??

https://www.jaguarforums.com/forum/j...upgrade-68305/
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I just went through your link and they saying that it work for STR.

""Total gains achieved by reprogramming only the ECU on the XJR/XKR/XF/S-Type R 4.2L Supercharged Jaguars is 25hp & 24lbs tq. By complementing the ECU tune with a pulley, gains are 55hp & 65+lbs tq."""

 

Thanks Tom I must be blind!! I just did not see it.

I can't find anyone with a 4.2L SC that has had it done or reported it?

Still hoping!
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You could be the first!

 

XFR is totally different beast, don't think you can draw any comparison between gains made with their tune on that application and a 4.2L STR,

Also, in the case of that one particular XFR receiving the ECUTG tune, that was combined with a pulley and exhaust too? Hard to say what gains are attributed to the tune, and which are due to pulley...

Best bet is, we need one of our modded STR members to do a baseline dyno run, apply the tune, return to the same dyno, and repeat a dyno run. That will give us our own relevant reading on what gains, if any, the ECUTG provides.

So far no ones stepped up to the plate, and I doubt that's going to change anytime soon.

 

Actually....

The 4.2L XFR is the same engine as the STR, apart from having Variable Valve Timing.

One of the members here in Switzerland (Crocodile62) put a 4.2 S/C from an XFR into his STR. Unfortunately it blew a head gasket & we haven't heard much from him since...

 

I was referring to this guy, the one and only ECUTG customer I've seen post on the forums,

ECU Tuning Group Review - Jaguar Forums - Jaguar Enthusiasts Forum

Which is a 5.0L SC XFR, on top of which, he did a pulley/exhaust mods IN CONJUCTION with the tune, so its damn near impossible to say what gains, if any, the tune from ECUTG was responsible for, and what the pulley/exhaust gained,

The 5.0L with factory roots twin screw blower is different enough from our 4.2 SC cars that I don't think any relevant conclusion can be drawn from that users XFR experience with a ECUTG tune, and what it will do for a 4.2L STR...

 

Ah OK, yes I agree. The 5.0L cannot be compared to the 4.2L, however if someone is offering tunes for the early 4.2L XF, then that is comparible.