Just wondering if anyone has undertaken basic exhaust / filter mods and got any proven before and after gains?

When I had my ITR I spent quite a while weighing up mods and the conclusion was headers, ITG Maxogen, Decat and Unichip yielded some good gains. I drove an ITR with those mods and it was a fair bit quicker.

The S2000 is obviously a different kettle of fish though...

Off to dissapear into the depths of the search forum...

Oh, still got to buy a car yet

MB

 

I think a few peeps have RR their car, I think steveM got about 8bhp at the wheels more than a standard car and he has a few proper mods.

 

Thread from recent rolling road day

https://www.s2ki.com/forums/index.php?showtopic=259554



Dyno sheet from just adding a Spoon N1 exhaust.

 

I think the dyno that day was on the lazy side.

 

So which lines are which Simon and are they adjusted for an assumed level of transmission loss?

 

Red is bhp, green is torque, blue is AF ratio, pink line is the transmission loss.

Take the figure of the pink line off the red line to give BHP at the wheels.

 

Says corrected for power / temp on the graph. The RR normally back calcs drivetrain loss on rundown after the main run.

Im confused as to the difference too though??

MB

 

Ah

Interesting the ECU leans the mixture out on / just before VTEC engagement (to bring in a touch more power) then flattens back. I presume an 04 car is flatter? Id read there is a bit more kick on the earlier cars, which would explain the leaning AFR.

Did they say why the peak was 10 bhp short? I know RR's aren't too accurate - but good for before and afters...

MB

 

I don't know why they bother making assumptions about the transmission loss. The bottom line that matters is how much have you got at the rear wheels relative to the car's weight.

 

Basically what they have done is measure the power at the wheels, estimate power loss and add that on.

Personally I wish they would just give a power at the wheels figure as there isn't a great deal you can do about transmission losses.

So take the pink one off the red one and you have power at the wheels.

IE max power at wheels is 229 bhp minus 31 which gives you 198 bhp at 8500 rpm, stock is assumed as 190 bhp at the wheels.