Graeme's S15
This car is possibly the rarest of all the S15's - cos it's completely standard! But Graeme has plans for it, so we decided it would be nice to get some "baseline data" by putting it on the dyno and seeing what one does as it comes from Mr. Nissan.
Graeme is one of the guys who has been patiently waiting for our "Type 4" realtime boards to be ready so he can tune the ECU in his S15. A few weeks ago we fitted one of the early prototypes to his car and it's been running very well. His car is a daily driver so it's the perfect test car, and he kindly volunteered it as a guinea pig.
This is an Australian delivered car. It's well known that we get a de-tuned version of the Japanese cars so the first thing I did was pull the factory maps from the ECU. It's true - our ECU's are de-tuned. Graeme dropped around one day and I reflashed his ECU with the Japanese maps (which I tweaked a bit while I was at it). This made the car a bit more lively.
--- I'll put the graphs here once I extract them from the dyno ---
Once on the dyno the usual deficiencies of any standard S13/S14/S15 SR turbo quickly became apparent. Firstly, they are run stupidly rich, and secondly that the factory intercooler is extremely limiting. We actually pointed the big cooling fan on the dyno more towards the side mounted intercooler than the radiator to help. While carefully watching engine temps of course. We had to wait a bit between runs to allow the intercooler to lose its heat. Without this the power would drop off markedly on the second run and any measurement consistency was lost.
As you'll see by the dyno plots, the AFR's get crazy rich above about 5000 rpm. So rich that the AFR mater bottoms out and we get a flat line after 5000. The result was a pathetic 100rwkw. We were going to stop here as we had our "baseline run" but I couldn't help but get in and adjust the mixtures. What amazed me was the difference it made. Over 40rwkw. And this was without optimising the IGN maps - once Graeme fits the bigger turbo, injectors, AFM and we turn the boost up the IGN maps are going to change a lot so I wasn't going to spend too much time there. I'd flogged Graeme's poor car enough anyway.
This was without touching the boost (all factory boost control parts are still fitted), although with the extra power being developed the boost did creep up a tad up top as you can see by the graph. A lot more could have obviously been had if we'd adjusted boost. But we'd already done more than we intended to anyway.
*** Please note that we did multiple before and after runs to ensure consistency and there were no dyno shenanigans going on. I don't sell tuned chips or anything, so I've nothing to prove. Tuning is merely a sideline that I do cos I love it! ***
A quick road test confirmed the graph. The S15 now has the top end it should have - instead of falling on its face above 6000 rpm.
The really fun part will happen once the upgraded hardware goes on and we turn the boost up!
http://www.plmsdevelopments.com/customers/gf_s15.htm