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Well this is my first post in the forum. I have read many posts and owe a lot of credit to all the people that have put in work on their respective vehicles before I started the venture on mine. It has taken me two months of work and today I will be running the vehicle on a dyno. I have a 2003 Jaguar STR with a Steigmeier ported blower, small upper pulley, tune from JR Tuning out of England (using the Byte Flash tool), and cat back exhaust with magna flow mufflers. As we all know the baseline for the STRs out of the factory is 400BHP, not sure if that is to the wheels or at the flywheel, but I will find out. I am in Albuquerque and am very proud of the look and feel of the car. I will post the graphs of the dyno later today along with some images of my car. Thanks for all your support through out this build process. Thank you.
Hey Clubairth1..I did plenty of reading and looking over and over before I made any moves on the Jaguar STR I own. It has been fun and a headache at times, but I believe it has all been well worth it. I am pretty stoked to show my "art" work to the forum.
The 400 HP factory figure is at the flywheel.
I'm interested in seeing your results, as I would like to make similar mods to my car. I'm guessing you'll be somewhere around 370 RWHP. which would be a healthy improvement.
Well, I have done the dyno after the mods. Still have some work to do to get the most power I can out of it. As you can see from the graph, my air/fuel mixture is lean and I need to richen that up. I don't think the smaller pulley created more boost as it has increased power throughout the rev ranges. As one can also see, I am getting 330 to the rear wheels at 4100 RPM. I guess it isn't bad, but I was expecting more. I'm not too disappointed because I did all the mechanical work. There is room for improvement.
My STR. Carbon fiber accent wrap on hood, roof, and boot. 19" MMR gunmetal wheels, H&R lowering springs.
I am still running factory CATS. I need to get the hi-flow cats right? Do I need to get new O2 sensors or just use all four (pre and post CAT) of the ones that are already in use?
From what I've read, the SC cars react well to reduced backpressure, so I'm assuming high-flow cats would help. I'm pretty sure your existing 02 sensors are fine, but I'm not an R expert, only having mine for a few months, but there are people on this forum who are.
Nice looking car - I really love those wheels!
Yes indeed, I know they will help. I just need to make sure I get the right hi-flow magna flow CATS for the vehicle. You know Digital Disaster, it took me 3 months to choose my wheels, and I am very glad I was patient. I think they go well with the look of the rest of my vehicle. Glad someone else can appreciate them.
Yes indeed, I know they will help. I just need to make sure I get the right hi-flow magna flow CATS for the vehicle. You know Digital Disaster, it took me 3 months to choose my wheels, and I am very glad I was patient. I think they go well with the look of the rest of my vehicle. Glad someone else can appreciate them.
Very nice looking car !!
I can see were you can gain 9-14 more HP , that plastic intake j pipe is a restricter .
Look up caldoofys stainless j-pipe upgrade its avalable on this forum .
High flow cats will only improve horse power if your stock cats are fowled with carbon , but will help the torque figure regardless .
You can look at your o2 sensor data via obd2 to see if they need replacing . My guess is that are fine .
And also you can check your cat efficiency with a lazer temp gun .
Both prosedures are on YouTube . Also check your fuel trims to confirm your lean condition is not caused by a failed or failing component !
Witch pulley did you use ?
Also you may want to look in to upgrading your intercooler pump and add a coolant capacity tank or all your work will be in vain . As the ECM will just turn the power back down when the temps rise .
The IC (pump/coolers/etc) is well worth improving but the big one is to change the SC such as to a KB TS (twin screw) because the Eaton is at the end of its useful power with an unmodified car.
...tune from JR Tuning out of England (using the Byte Flash tool)
Oh dear, not one of these things.. explains why your AFR's are so dangerously lean... in the 13's at WOT is burning up... especially with a smaller pulley fitted.
Oh dear, not one of these things.. explains why your AFR's are so dangerously lean... in the 13's at WOT is burning up... especially with a smaller pulley fitted.
Put the stock tune back in if you can!
Woaw ! I forgot the Wide open throttle was a set AFR parameter!
That is dangerous !!
It makes me wonder what the rest of the load AFR's are like .
Judging by that though my guess is not good .
It's tough to get more power on a STR. We just don't have many mods and the short lived TS is gone
Here is a Supposedly stock STR run. Not many car details and as always the dyno and other conditions are different so not a direct comparison but thought you might want to see it.
2003 Jaguar S-Type R
