Hit the dyno today, mods are in my signature. About as expected, maybe a little higher in the torque department, but no complaints there . Done on a dynojet, SAE corrected. I was planning on hitting the drag strip this evening, but its been raining for over 12 hours straight with no signs of letting up, so that is likely out, maybe Friday though. Shown is my best run, the other 2 runs were within 1-3 hp and torque with the same curve:

 

Not bad! Now the question I have is that I hear that these cars put down ~330hp, so with the mods you had you only gained 25hp? How hot were the aftercoolers?

 

It sat for about an hour after been at full temp, I didn't take temperature readings. The readings can vary based on what type of dyno. I wasn't expecting huge numbers over stock, the high flow cats and intake are mild, and the pulley is more about gaining through the power band, not necessarily peak power gain. The same shop had previously dynoed an '07 XKR with similar mods and it put down 4 more hp and 4 less lb-ft. of torque.

I should also add the disclaimer that I am at 5500 feet in altitude so the SAE corrections might not be exact either; but I feel its an accurate representation of what to expect with these mods. I should also add: as shown on the graph, humidity was 42%, pressure was 24.58 in-HG and temp was 71 degrees Fahrenheit; the local climate here is plagued with low DA due to altitude and general dryness so I'm not sure how they calculated the SAE correction.

Comparing to this thread, it sounds about right with just a pulley and high flow cats difference, but no full exhaust or modified rear boxes.

 

holy crap!!! nice torque!

 

Wow! Quartz, she's a torque monster. 405 rw trq? So what is that at the crank? 480? Wonder what an ECU tune would do for you. R U using the stock rear boxes? Is she quiet in the cabin? I'm looking into going back to a stock-like rear muffler...too much cabin drone whilst under a load or climbing a hill in high gear. Otherwise good dyno-job and write-up.

 

Sorry I wasn't trying to dissuade the results at all. It is just hard for us to make any real power with these cars. Do you think you will be doing any cooling in the future?

 

I am contemplating an off the shelf tune, but with winter closing in I likely won't be pulling the trigger until next spring if I do. Still have the stock boxes; I will be looking to change it up due to the rasp I get between 1800-2300 rpm. I'm not sure if its in the x-pipe or the boxes at this point. I thought it was the x-pipe, the dyno shop said it could be in the boxes. I want to change them out anyways, so I will be addressing that end first (maybe set up some sort of trade?). I will be shooting some video this weekend at a large British car show; I'll be sure to post some up.

I wasn't taking any offense. The aftermarket is definitely scarce, expensive and somewhat effective-less for our cars, so one must be careful trying to make every penny count. I was a bit surprised by the torque number, but at the track I've run .8 faster than a stock STR while trapping almost 10 mph quicker, so the mods definitely show some real world effect. I'm not sure the what the conditions were when my friend ran his, but he said he couldn't get better than a 14.7 in the mid 90s; while at the same track I've hit 13.9 @101 (again, the DA at Bandimere is usually around 7800, making most cars at least a full second or more slower than they would run at sea level). The only video I could find of an STR at Bandimere was here, but fair warning the time is not so great.

I talked to the tuner at the shop where I dynoed, and asked him about meth injection, nitrous and the "killer chiller" type of set-ups. He said that a lot of the cars he dynos get more power without the meth injection set-up, and was definitely not a fan of that idea. Nitrous is more of a personal preference; whether or not you want to risk it. He wasn't real familiar with the "killer chiller" but he had the same thought that I did: If the coolant temps get too far below operating temperature, it will just make the car run rich trying to get back to operating temperature, and may not have any real effect power wise. I have researched them a little, but I haven't looked close enough for dyno differences (probably get them from some Mustang guys). I can see where it would be useful to cool the car between runs; but I think some prejudice must be made as far as not to overuse it and get too cold. I forgot to list that I do have the low-temp thermostat, and I'm not currently planning on doing any more for the cooling system at this time.

 

A better intercooler won't make the engine coolant cooler. Only the intercooler, thus the air charge. Won't make it richer except that being cooler it will be a bit denser thus a little more fuel and better timing.

The STR has an extra IAT (IAT2) that is after the air gets intercooled. Engine temp (ECT) is not really what you need to care about much.

You'll really struggle to make it too cool. Will take real effort...

 

Thanks for clarifying that for me. I was under the impression that a "killer chiller" type unit was to keep coolant temps cooler; but it makes a whole lot more sense to me now. I was more concerned with IAT than coolant temp, I guess I just wasn't able to make the connection to cooling the coolant to cool the air.

 

The STR effectively has 2 separate coolant circuits which happen to share a common pressurised header tank.

 

quartz, a "Chiller Killer" should def. allow for maintenance of max. timing thus maintainence of power...she'll feel as powerful like a cool morning drive...before the charge coolers heat up, but in the case of the CK, the intercooler circuit is maintained in an appropriate heat range that deters the ECU from pulling back timing. Of course, a twin screw makes this entire process moot. In cool weather, my 03 STR kicks *** before full warm up until almost 30 minutes thereafter. I'm guessing 480+ lb/ft tr. that comes on incredibly low on the RPM scale and continues pulling hard throughout. What cats R U using? R they the 49 state legal hi-flows or 50 state hi-flows?

 

I'm definitely patiently waiting for a twin screw kit. All these other mods are tinker toys in comparison. I am running the OBDII cats, Magnaflow 99675HM instead of the OBDI 59975s that many others run. I'm not sure if they are California legal, but I have no CEL or limp mode and I am not running O2 sensor extenders. I credit the torque mostly to the pulley; its the biggest difference of all the mods that I've done. It was the first mod I did, and I was able to run a 14.1 or 14.0, which is about .7 faster than a strong stock STR runs around here. After I did the intake and cats, I was only able to run a 13.9 in similar conditions with near identical 60' times, but I did gain almost 3 mph in trap speed; so horsepower was definitely increased. Thanks for the info on the chiller killer, I will have to look into it a little more deeply.

 

OMZG, can you tune my STR too, soo cheappp????