I would then know the ECU you have and could find out how it is programmed to see what can be done.

 

May have good news ;-).

I have tried my idea on a STR today, and the first results are very good. Am going to fine tune it more tomorrow to find the tresholds, lets hope this worksout.

 

Still have good news; all is still working on the STR with the bypass surgery ;-)

Did have to do some fine tuning to make the effect mentioned earlier unnoticeable, but it is doable and it is working like a charm.

 

Could you please elaborate on the "bypass surgery" and tuning.
I have a 2003 STR and would be very interested in this.

 

Did have to do some fine tuning to make the effect mentioned earlier unnoticeable, but it is doable and it is working like a charm.[/QUOTE]

Hi guys, since I'm relatively new to the Jag scene, I was wondering and the answer may be obvious, so it seems: Is this method of blocking off the egr valid as well on a '99 XJR? How do you do your tuning, with what equipment? Also, how well does your third member hold up to 600 hp? Just what differential is Jag using now anyway? I know they used to use the Dana 40's as I have a couple of them. The R series don't come with posi? Does the R series use lower gears than the others?
Sorry for the slew of questions. Just trying to understand my car better. Thanks

 

If you would like a pozi setup with a different gear ratio I have a setup for sale to convert your car fro 3.07 open diff to 3.58 pozi. Let me know.

 

@Jagman99R
The EGR code came back after a while, and I need to check what it is, I think I have an idea, but the problem is we live to far apart. It will be either something simple (of which I have an idea) or I need to tune it a tad more. For most driving it works, just under a specific condition it comes back. So it will need some more time.

Now I am not sure if a 99 XJR also has a vacuum meter, if you don’t you can just leave the EGR connected, and block of the pipes, that will work. What I am working on is for cars that do have a vacuum meter from which the ECU can detect if the EGR is working (almost all models from 2000)

I was lucky with my 2000MY, as it didn't had a vacuum meter, it seems that only the American market does have one for this model year, so there you can't just blank it off. Only trick there would be to flash the ECU with another market value, but that is for a specialist (only for the 2000 models)

Jaguar hasn’t used any LSD anymore from the X308 model, so you do not have one, but there are options, i.e. clutch plate systems or the quaife unit. I did see the word Dana on the main gear, but I have no idea who makes them.

The first Diff did hold up very nice, that was with a custom clutch LSD, however it failed on me (not the LSD part, but the small pinion gear). The cause was an accident I had a long time ago, and the diff started a slight noise when decelerating immediately after that. This worked out for a long time and I had a spare diff already packed to have a LSD build in so I would have a spare one, needless to say that within a week that I had packed it (but not send) it gave up. Verdict: a bearing was going and that took out the small gear. I did prefer to put my clutch LSD back in as all was ok as far as I could judge, but to send it off to have it fully checked, and before I had it back would take too long (I need my car as a daily driver). I could get a Quaife unit within 2 days, so went for that. It is different, and I need to get used to it, and was hesitant at first, but so far I like it.

I have also converted another car in the UK to a Twin-Srew (2 years ago already), and his diff is working fine under the extra load. There was recently a nice article about his car in Jaguar World Magazine (may issue 2010), you can still see it on the front page “XKR Charger”:
http://www.jaguar-world.com/

If you stick with modest performance changes then it could be interesting to change gearing, however if you plan on serious performance changes (IE a Twin-Screw), then I wouldn’t recommend it.

 

Hey, thanks for the offer but I think I want to stay with the higher gears. Wouldn't mind the posi part though. Lots of potholes in Beantown. How do you keep your car in one peice?

 

Avos. Thanks for the reply! Good info. How does one go about tuning their jag? It will be a while before any of this happens but I like to be in the know.

 

All depents on where you would like to go, and also how you like to reach it, as an example I am still enjoying the road to it and of course the finalresults.

I am maybe the wrong person to ask, as I would expect some proof for mods, and that seems to be scarce somehow,eventhough some products are available for a long time, but getting good dyno results are just some how not available.

The best start imho is your car is in tip top shape, which could be tested via a base dyno. The results also need to be interpreted as there are different dynos on the market, and you should preferably use a mustang dyno or dynojet, but not dynos which have dual rolls per wheel. Not the environment variables and I can help to interpreted the values.

Only then established your car does reach the expected values (I s in good shape), you could go to a next step.
That next step depends on what you would like to reach. I would wait here for some members as they try to get the maximum out the standard eaton supercharger carger, which has its limits, although it could very well be in the line you would like to do.

But for serious power continues power (withpout using nox or so), a tin screw or Turbo setup is the way to go.
I have a solution of the lack of power of the engines, by replacing wit special intakes etc with a twin-screw, but that does not come cheap


Andre

PS There should releale become a Performance section imo, this will help to keep the performance related info together, H2O is this something to discuss?

 

Hi Avos, perhaps I should be a little more specific. What tool are you using to re calibrate or tune your Jag? Laptop interface, handheld programmer, dyno-tune etc. I haven't yet found any programmers for it. So, how do you do it? Does someone sell a chip for it? Probably you are a Jag tech, or someone with access to the proper tuning equipment but for the rest of us poor folk, what do we use? How does one do just some "basic tuning". I wish I could get a Kenne-belle kit, it must be awesome. Can't even imagine the difference. Is there an available girdle for the salisbury axle to stiffen it a little? It seems that even in stock form it may be a little taxed in it's ability. Just some thoughts. Thanks for your insight into the matter. I'm just trying to understand the Jag world a little better and perhaps at the same time make mine a better Jag at the same time.

 

Am a simple mortal myself, just an enthusiast and started tuning myself as the pulley changes just didn’t work on my car. I have the WDS which helps me understand the car better and ECU/Engine behavior. I can’t program myself, but know a lot who can. So far I haven’t done a tune on my car, I want the ECU stock to test out all the different setups. Only when I know how I want my final setup, I will make a specific tune for that setup. With basic tuning I mean that the ECU is dumping in excess of fuel in the higher rpm regions, probably done to lower the charge temp and get a good safety margin. This is understandable as these cars should also be able to run extended length at full throttle on the German autobahn and do many miles in which parts of the system could deteriorate.
So if you have a stock car and you do not have the ability to run extended lengths of full throttle, then you could imho adjust this extra fueling. Just do not go to lean, it is tempting to go to 12.5 or so, but then you take away some good safety margin. Now let’s forget the autobahn, imagine that one injector is a tad clogged, then that cylinder would get even a much leaner mixture, which could be bad if you see what I mean.

The KB kit is indeed awesome, but am a bit biased ;-). Anyone is more than welcome to visit me in Belgium/the Netherlands, and am more than happy to demonstrate.

 

for those who have gone through with the removal of their egr valve, can you guys summarize some of the problems you have encountered, or improvement you have gained.

 

Have the STR since this weekend to fine tune/test the EGR deletion amongst others. I had to adjust the orifice a bit more, but think it is working now, though need some more test drives. I will be able to update end of the week.

 

Gentlemen; I've removed my Eaton from my '04 STR in order to replace the leaking
coolant hose (see my posts elsewhere in S type - removing my supercharger). I'm
interested in any recent findings on methods to tune the STR if you'd care to
elaborate ?

I also would like to request your latest findings on removing the EGR. I'm not as
knowledgeable as you fellows, obviously, but am learning quickly. Have you had any
luck removing the EGR since these recent posts ?

I'm sticking with my Eaton, but it's going to Stiegemeier for the "Snake Bite"
treatment this week (70+ additional HP). I will be posting on results and reinstalling
the supercharger with a few accommodations to reduce install time.

I'm not familiar with the "twin screw" blower. Can you enlighten me about that ?

Tally Ho

 

I still have the car but now without ECU as that has been send to the UK for a basic tune.

The EGR removal as I have described in this threat is working, thoug will do some more testing when I get the ECU back. Final test is when the owner gets to drive it, and I will update here.

Don't get your hopes up to high with the 70+ extra hp, I for one will doubt this very much. I would suggest making a deal with steigemeyer to see how sure he is, for every HP lower than 70 you should get a discount and anything higher you will pay extra (don't worry about the latter ;-).

Have you already done a base dyno?

 

No, I know I should have, but the coolant hose ruptured so I had to repair
it and wasn't about to reinstall for a base test.

Stiegemeier normally says this kit is a 100HP increase for Cobras, but
since the Jag is a different configuration, only 70.

 

I hope you get what you look for, but 70 extra hp on our cars goes against my personal experiences. For reference most good standard STRs should get about 330/340 rwhp (on a single drum wheel dyno), I would guess you could get maybe 360-370 with the snakebite in a one shot run. Doing a couple of wots on the street would only give you the first wots good power, then it hp output will lower due to the heat buildup.

Forgot to answer about the Twin-Screw:

The standard supercharger (Eaton) on the Jaguar is of the roots type. In short, this one pushes air with large flat blades into the engine, somewhat similar to the old Mississippi paddlewheel boats. The newer versions from Eaton (TVS, now in the 5.0ltr cars) moves more to a screw type, great improvement over the M112 roots version.

A twin-screw supercharger is more advanced and works more similar to the modern screw driven boats. It also does something extra, and that is compress the air already in the supercharger case via 2 different size screws, which is much more efficient then trying to push air into the engine via the paddle mechanism of the Eaton.

With a proper twin-screw setup, gains are easily starting from 100 (bone stock car) up towards 200 extra horses, where the latter would depend on other mods like ecu tune, exhaust etc.

There is a place for the roots type supercharger, it is cheap to manufacture, and relatively ok with boost no going over 11 psi (for comparison, in an older Twin Screw setup I tested with about 12/12.5 psi gave me already 60-70 horses more to the wheels!).

The drawback of the twin-screw type superchargers is that they are more expensive to manufacture.

Here is some more information about the 2 different superchargers:
http://www.kennebell.net/techinfo/ge...romcatalog.pdf

 

You may well be right Avos, we'll have to do a pull when I get it all back together. Stiegemeier claims the Snake Bite performance is using the
stock pulley.

Thanks for the info on twin screw. I just didn't know to what you were
referring. I've seen info on the Kenne Bell, et al.

I've been pretty satisfied with the stock STR, so I feel sure the Snake Bite
will give me goose bumps. I want to do a few more mods, but don't plan
on any extended racing; I just love the power. I would like a better free flow exhaust and a good cold air intake to improve flow.

Any suggestions/recommendations ? I understand Mina has a CAI, but
their exhaust is far too expensive.

My son-in-law is an ASE certified Mechanic and races his '03 Mach I and
turns in the low 11's normally aspirated and has now moved to Texas near
me with my daughter who is in the U.S. Navy stationed recently here. He
will be assisting me with tuning as he has some good connections and runs a performance operation wherever my daughter is stationed. Last station
was on Guam.

 

The snakebite is doing 2 things; 1) port of the supercharger and 2) adding a gear system to spin the SC faster (same as changing a pulley, but noisier).

As you can see in the posts/attachment, heat (amongst others) is one of the biggest enemies with the roots blower, and the higher the pressure the worse it gets. So anything you can do to lower the discharge temps will be of help, ranging from better radiator for the intercooler (and also better pump), reservoir in the coolant system to add more buffer, alky kits, or the killer chiller system.

The next one would be the whole intake system (so from intake elbow to airbox), as the more vacuum you get before the inlet of the supercharger, the less efficient it becomes as the higher pressure after the rotors and vacuum before the inlet work against the engine, so this will cost extra engine power not being given to the wheels.

Only if you could do considerable steps here you can make some good improvements.

Please forget quickly all the hot air filter systems like Mina is offering, unless of course you are interested in lowering the performance of your engine, and want more heat into the system…

It would be great if someone could come up with an air box that gets the air from outside (like the stock one), but can fit a larger panel/cone filter, as that will reduce the vacuum again a bit, thus results in more power.

I am still in doubt to develop a totally new intake elbow, as that with the current TB is just creating too much vacuum. But that would be very drastic, best would be then to relocate the TB probably just above the SC, and preferably also a bigger one. That will enable you to get a more smoother/bigger path from the SC towards the TB.,

However with the twin-screw setup I already have been able to get out about 420 rwhp of the STR and hope the tune will bring even a bit more, I will get the ECU back next week. I could probably also get more out of the setup by using Alky system etc, but personally I like a clean system, so am not perusing these roads. Though it would be great if someone could make an air box as described!