I have seen both Jeremy R's and ERP's dyno slips and while ERP appears to have the more heavly modded car he makes about 10 less HP than Jeremy.
Is there any reason for this besides differences in chips?
My car has the 3" JT downpipe and exhaust, intake mods, polished throttle body casting and I just bought the Stage 3 SpeedParts chip. Nick at Taliaferro estimates my car should make 245hp and about 265 lbs of torque.
Does this sound accurate after reviewing your DYNO results?
Are any special requests I should concider making regarding the way my chip is programmed?
Any help you can offer will be appreciated.
26-02-03, 06:10 PM
I'll have to check my dyno slip tonight and tell you exactly what it says. I know my torque readings were lower than a lot of other modified Saabs I've seen, but then again, I haven't done a whole lot. I bet a manual boost control really adds a lot of torque. If I take it to a dyno again this summer, I'll get to see what a straight center exhaust pipe and a Speedparts ECU will do. The ECU should arrive in another week or so. I can't wait!
From the research I have done I am pretty sure the reason for these variations is the boost control. When using an MBC the ECU realizes that it does not have control over the boost pressure and retards timing at higher pressures and rpms. This causes a decrease in max horsepower. However after comparisons with other dyno charts I have found that using an MBC gives me a higher max boost and torque by 30-40 ft-lbs. A good example is NickR for Canada, he has almost the exact same setup as me and put down 224 whp and 224 ft-lbs.
I have also noticed that people without cats tend to put down slightly higher max horsepower, which makes sense. My preference to use a MBC is for two reasons. First I have a stronger mid range where I drive most of the time anyways. Second is throttle control. With the MBC throttle position is directly correlated to power, but when the ECU is in control different throttle positions will give varying power out puts. Basically with the MBC I rarely floor it, but with the ECU controlling boost I found I had to floor it all the time.
It comes down to personal preference and driving style, so just try both and see which you prefer.
-I haven't seen Jeremy's dyno, could you post a link, thanks.
So what you are saying is that with an MBC and the Speedparts chip I should make more power than with the chip alone?
26-02-03, 10:00 PM
I can't remember what I guessed at before, but maximum horsepower was 173.1 and maximum torque was 194 ft-lbs. I might have guessed 10hp high (wishful thinking probably). The only mods I had that day were a Viggen Sport Exhaust muffler (no straight pipe) and a Viggen intercooler. I don't have the graph scanned and posted on the internet, but I'll have to get it up there one of these days. I'd say that 265hp sounds about right for what you're doing to your car. That chip alone is good for well over 40hp, especially when it's the stage 2 version with the downpipe. Of course the numbers Nick gave you were for horsepower and torque at the crankshaft. I'm guessing that my car is losing 30hp through the drivetrain. As for special programming, as long as you put all of your performance mods on the sheet, Speedparts should program it fine.