From earlier posts I saw that ECU tuning cost around $1000. It was promised by vendors to add 30+ HP to an STR, but no vendor ever produced a dyno printout to back up that claim. There were a few comments in support but, by and large, forum members did not believe that ECU tuning was all it was promised to be.

Lately, however, I have seen ECU tuning mentioned as a power upgrade step.

Have I missed something? Is ECU tuning for real now? If so, which product is recommended?

 

I think I know the post you're referring to, but no new tuning options have available or at least as discussed on these forums.
The engine management will 'adapt' and respond to mods and show gains without necessarily having to tune it.

The most rewarding 'tune' would be to over ride the TCM's short shift of gears 1-3.

I want to try my hand with the mongoose JLR interface mentioned in other threads, and use it to flash the TCM with an XKR file, thats been purportedly made to somehow work in at least one case...

 

From what I've read at the XJR and XKR forums, the ECU tune made a noticeable difference in throttle response, increase of approx. 25 rwhp, and its maintenance throughout the power band. I'm going to go with ECU Tuning Group ECU tune after an intake manifold gasket repair. May even do Stiegmier port and water cooled front snout. Then long tube headers to top it all off. Or do ECU tune last?

 

bfsgross, Do the ECU tune with your current set of mods as the results would be very relevant and informative to most lightly modded STR's on this board.

A before and after dyno would be great; try not to pile on all those mods at once, because isolating gains from the tune, if any, would be great and help dispel some of the apprehensions and skepticism surrounding ECU tuning groups claims.

 

K, will do ECU tune soon.

 

Thanks man, you can be jag forums official STR test mule

Follow that up with an avos' TS kit install and dyno, and we will be forever grateful for your work,

 

Already tried the XKR file swap, made no difference, 1-2 is still at 5900rpm...see my other thread in the General Tech Help...

 

I feel pretty hopeless on ECU tunes. The only thing I can think of is someone doing a stand alone or a piggy back, but good luck finding someone competent to handle those lines of data for you.

 

I wonder if swapping a later year STR file into the TCM would help with the short shifting?

My 2005 STR hits 6000-6100 in all the gears I can check it in. Which is only about the first three on most roads!!
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We can try swapping in the later TCM file.

 

My 2005 is the same way.

Funny about the first three gears. If I wanted to see the top of 4th, 5th, and 6th I would need to take her out on the salt flats at the world of speed.

 

No ECU tune solution (not that big of a deal), no TCM tune solution to cure the short shift, no (affordable) LSD upgrade in sight... kind of a disappointing week for the STR, very tempted to go trade her in for an 03 porsche 911 C4S I been eyeing...

 

Your beautiful STR already cooks...no need to be disappointed. A Quaif LSD can be installed, as well as an ECU tune, etc.. The TCM shifts her at optimum points on the powerband. Admittedly I would love to rev her out of the powerband too. I'm betting all the mods we have now along with the soon to concieved will allow 480+ chp: Mina and Caldoofy intake (20+ chp), 1.5 and 3 lb pulley (15-20+ chp), blower porting (20+ chp), ECU tune (20+ chp), hi-flow cats (10+ chp), long tube headers, x-pipe, free flowing mufflers (30+ chp), as well as monstrous torque. Quartz's STR has: K&N a/f, modded intake tube, and 3 lb pulley belting out 360+ rwhp @ 405 lb/ft rwtrq., all this despite having not recieved all the mods available. I want Quartz to pop back on hi-flow cats and full intake mod (Caldoofy intake tube and Mina Intake). Bet his STR will belt out 390 rwhp @ 425 lb/ft rwtrq.

 

I hate to disappoint you, but my dyno was with the 3# pulley, high flow cats with x-pipe, resonator delete and my ardesign intake (just like the others, just 3.5" instead of 3" piping). All I've done since the dyno is delete the mufflers and add a resonator on each side just past the x-pipe. I could add the Mina filter, but I wouldn't expect any real results. I've been considering a Eurotoys ECU flash or similar, but I don't think approaching 400 whp is possible without a blower upgrade or dyno tune. I've also read that porting the blower really only helps out with power at the very top of the power band and robs it down lower. That might be conjecture, but without being able to dyno our cars throughout the whole power band (only 3500+ rpm) we will never know for sure.

Long tube headers might help, but judging by the very small gains from the other mods, I wouldn't hold my breath for huge gains on the dyno or for shaving a few tenths off the 1/4 mile time. I would expect something closer to 15-20 whp, maybe a tenth or two quicker down the drag strip and people not happy with the extra noise.

After seeing dyno results from several members with similar mods when comparing to stock, the fact is all the bolt-ons we have will only net us ~40 whp. Stock these cars typically pull ~315-320, and with mods such as mine...well its not all that great of an improvement honestly.

Like you said, the car is already plenty fast, but the fact remains there isn't much room to grow with basic bolt ons. If one is looking for a lot more speed or ability to mod, the STR just isn't the platform as there isn't much aftermarket support. I've considered switching to an E55 (I'm not into the CTS-V), but I'm happy with my STR as it sits. I can still go out and roast the unsuspecting Mustang, SRT8, Camaro, M5 or what have you and they don't even know what my car is. People know what the E55 is, but they aren't that familiar with what Jaguar can do.

 

Thanks for that!! I spit beer all over my keyboard when I read your post!! These things have a LOT of top end!
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Thanks for chiming in Quartz. Judgeing by your post, I just wanted to let you know again that the addition of a Mina intake will take you by surprise. Install it then perform a hard re-set of the ECU.
Some of us have been in contact with those who've modded and finally recieved an ECU tune from Eurotoys and ECU Tuning Group. Their resounding claim is: an ECU tune is the way to go either with or without other mods. I respect Avos for all his wisdom and experience. However, there is too many claims touting the immense effectiveness of an ECU tune for me to ignore it as just a side note to modding our STR's. Those who've modded and then recieved the tune suggest that it brings the individual virtues of each mod together. I'm going with ECU Tuning Group's ECU tune.

 

Until one of these so called tuners does a before and after dyno test it's all smoke and mirrors.

Think about it. Why would they not do a dyno test?? Then they could crow about the DOCUMENTED power gains instead of all this hand waving.

The blower porting has turned out this way too. A bunch of money and the proof is very thin at best.

After all I WANT to believe in all these power gains too!
I just can't until better proof is offered.
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Please let us know how it goes (hopefully with a dyno sheet )! I'm ready to pull the trigger on an ECU tune, but I'm disappointed with ECU Tuning Group's lack of responsiveness on this forum, especially since they are a forum sponser. Either way, if it works out well they should get some business!

Is there a timetable set for your flash to be done?

This is more or less the complaint of myself and several other members most specifically directed towards ECU Tuning Group. If real (say 25-40 hp at the WHEELS) gains are measured on the dyno from just a flash, they could easily sell 20+ flashes just to the STR guys on this forum alone. $1k for 30 whp would be the best power gaining mod on the STR at this point at a relatively reasonable cost when compared to the other mods available.

Eurotoys says the dyno results of an STR with their ECU tune and Arden sport exhaust as being 435 bhp and 488 torque on their website.

 

May pull trigger on ECU tune next month.

 

Agreed, you figure if the results were there, they would advertise heavily with them.
The only good review i've seen is the one XF guy who gained 50tq by redline, contributing to a 60hp gain by redline.
Besides the fact that this was on a 5.0L twin screw engine that is nothing like ours, consider the before and after dyno also included a pulley upgrade, it's difficult to gauge what mods did what. Of course ECUTG takes fulls credit for it's tune being able to 'take advantage' of the other mods,

Also, there's a lot of loose power numbers flying around on this forum, with all the dynos reading 'low' and 'crank' horsepower estimates...


First and foremost, an engine makes torque, and the torque curve is what is being measured and examined when you strap your car to the dyno.
Horsepower, is derived with a formula based on torque, TQ x RPM / 5252

The two are completely related, torque is what causes horsepower to rise to redline. Horsepower has more to do with understanding acceleration, but in terms of measuring the power the engine is making or gaining, you're looking soley at the torque curve.

So, the goal of modding your STR is to make torque gains, and if you want to see a higher 'horsepower' number, you have to make the torque gains closer to redline,

Torque. If we are talking about measuring 'power' of the STR's engine, find the trace of the torque curve, and run your finger over it from start to redline. When I am tuning the wide-open-throttle power curve, I am looking only at changes to the torque curve dyno after dyno, and seeing where changes to ignition timing, cam timing, and fueling have made gains and losses. This is one of the most fundamental concepts in engine tuning 101.

As for dyno's, they all read different, but these cars are all making generally the same amount of power. That's basically 300-350 torque on the dyno reading.

I don't even want to call it 'wheel torque'. Because the dyno is NOT displaying wheel torque.

Not to get too technical with people, but actual wheel torque in 4th gear at higher rev's is probably several thousand pounds of torque, through the magic of gearing, the actual torque at the wheels is magnitudes greater than the measly figures the dyno is displaying.

Instead, the dyno's programming, has its own internal formula to determine what it displays as something close to what their engineers consider torque at the crank.

The dyno does not measure horsepower. Again, it calculates the horsepower through the TQ x RPM / 5252 formula, using it's own assessment of torque.

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Generally, the STR's seems to dyno out at 300-350 tq.

You're not always looking to make massive gains in peak tq numbers, instead, you want to smooth out and hold your peak torque (around 4,000rpm) for longer, and that is what makes 'horsepower' and that is what makes a car go faster.

In fact, upping peak torque drastically, is a lot more demanding interally and on fueling requirements in many cases, than simply smoothing out peak torque and reaping the benefits there.

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If you're interested in doing an ECU tuning group tune, please do a before and after on the same dyno, and don't do any other mods, this will be a great resource for the STR community,

My concern is as follows, if the dyno proves little to no gains, I'm sure you'll instantly get the explanation that the tune is very 'adaptive' and you have to give it more time, and that the 'gains' aren't necessarily measurable on the dyno, but in real driving conditions, the tune is doing its thing to gain power, the tune is more to take advantage of more mods you don't have yet, etc,

Consider the average high-end car driver who buys a $1,400 tune will easily convince themselves they got something, either power or the ubiquitous claim of 'throttle response'.
This is the 'emperors new clothes' of blind automotive modding, when it comes to selling super expensive tunes to a crowd that generally spends aimlessly on their high-end european cars.