Power Pages
S15 Upgrade Blueprint
Viper, our Hypertech contributor, shows us what he achieved with his S15 with a few simple bolt on mods.
I bought my S15 about 19 months ago. The car first drew my breath away in 2001 when I first laid eyes on it in Singapore. I could not afford the car then but things do have a way of coming back your way when you least expect it. I was shopping around for a car and there it was, a rare example of a stock S15. Well almost completely stock. One year on the car had been upgraded with a complete exhaust system with a Tomei Expreme manifold, Tomei turbo outlet, blitz downpipe and a Fujitsubo catback exhaust. A Tial wastegate was added to help ensure that consistent boost was by the T28 ball bearing turbo.
On the dyno the car generated a decent 222whp and 190ft/lb of torque. The turbo was boosting approximately 0.8 bar. A quick check with James from Onward motorsport and I was informed that the turbine had the potential to take approximately 1.1 bar of boost. This piece of information made me dig deeper into the cyber world to see what else I could do to maximize the potential of the SR20DET engine. Three things immediately popped up, turbine, cams and of course more boost.
KSP has been distributing Brian Crower Cams for some time now and they had a set of SR20DET cams that suited my application, plus I did not have to get rid of my NVCS. The cams I had selected featured a 264 degree lift duration. Since I was going to leave my car in the workshop for some time, I opted to do what I can to maximize the down time. In the shopping basket went the Cometic 1.2mm head gasket and the ARP head bolts. A set of rocker arm stoppers was also ordered.
Independent throttle bodies are more favourable because they allow a more direct path for air to enter the combustion chambers. The downside to this is that they can be notoriously difficult to tune, which is why Avantgarde chose a Hondata S300 EMS to handle the task. The Hondata is the best ECU/EMS that a Honda engine can get as it is feature packed and can handle anything that the engine needs.
The day came for me to put the car into the workshop, KSP's mechanic skillfully put the car together with the greatest of care and had everything back to me in 3 days. The words of the mechanic as I drove out of the workshop "don't over use your right foot, let the parts settle in first". So I gingerly drove the car home without any excessive use of the throttle. That night I drove the car around with the occasional prod of the throttle, I noticed that the powerband had changed dramatically. The power now flowed from as early as 3000rpm all the way to redline, where it used to run out of pull at 6K rpm. The new D2 suspensions had lowered the car's stance and the more precise damping made short work of the corners. The handling change was made even more obvious to me as the corners that used to unsettle the car at higher speeds now felt very tame. The new shocks handling and pull was very addictive, so much so I had used up half a tank of gas driving around aimlessly for the night. The next day I was back at KSP again. This time I was there to have the lubes changed, after which on the dyno it went for a proper tuning.
Dyno tuning was provided by KSP's mechanic and Joshua from Millennium Motorsports. The airflow was first adjusted and corrected to the tune of 11.5 : 1 this coupled with the boost increase to 1.1bar and a minor adjustment in the timing department brought the cars final power figures to 257Whp and 220ft/lb of torque. The car had more oomph from almost the entire rev range and had the suspension gave the handling that was sorely lacking with the original setup. My next set of upgrades has already been planned, be sure to catch the next segment of the S15 upgrade saga.
Product
Brian Crower camshafts
Cometic 1.2mm headgasket
Rocker arm stoppers
Fuel pressure regulator
D2 Fully Adjustable coilovers
Power
Before 222bhp
After 257bhp
Gain +35bhp
Torque
Before 190lb/ft
After 220lb/ft
Gain +30lb/ft
Contact
KSP Power
03-5636 0000