Just wanted to see what you guys thought of my dyno graph. I have a 96 Rs with iceman intake, dc 4-2-1, and crappy custom exhaust with 2.25" crush bent piping and an OBX n1 style muffler. I did a little better than I thought I was going to do...
another person whose car likes 14.0:1 AF ratio....nice "AEM hump" in between 4000-4500 rpm (your peak torque is there briefly) from the single stage IM and use of a long intake. your true powerband is from 5000-6000 rpm....this is where you want your shifts to fall to. the tuner did the best he could to flatten the torque curve but she needs some help from 4500-5200 and from 5600-6000 rpm on the fuel tuning.
this is why you should be skeptical when you see an intake company quote their peak torque gains numbers. as you can see if you report the peak torque from the "AEM hump" it is not truly indicative of the performance of a car but the biggest gain was there at th "hump". In reality, the intake did not add the main torque gain where you want it.
This is true for all CAI's...it's called the AEM hump because that's where it was first observed but even in this Iceman CAI you see it.
Notice that in the Comptech Icebox which uses a short ram that is surrounded by a box that is fed cold air, you don't see this hump. It is purely a function of the intake's length coupled with the IM design.
and this was just baseline numbers no tuning. I plan on getting a carsound cat, bumping the timing up to 18, getting a better mandrel bent exhuast, remove my power steering,and maybe cam gears. I also might get a legend air box and make my own icebox setup, then I should be where I want to be...
my english must be pretty bad since 2 people didn't understand my point and took it to be the opposite of what I intended.LOL.
I said that you want the rpms to FALL TO that second are of higher torque since it lasts longer. If your rpms drop AFTER SHIFTING to the AEM hump (the highest torque point on the rpm range that you have), it will last a whole 500 rpms...too brief....you then drop your torque after 4500 rpm...that's a hole in your acceleration...you don't want that. You want a powerband to be wide and as close to peak torque as possible. This is where a bit of planning when you choose & buy parts to a package and tuning comes in. You design the shape of your power curve and where you want the power to be and how wide. You know that the AEM hump is just an advertising/marketing teaser and not the real area of gains. Your butt dyno feels that AEM hump as a gain but the timer bases it's results on that second area of torque increase and how wide it is.
tuning costs from $100-150/hr if you have the dyno shop person do the tuning for you. If you do the tuning yourself or bring someone, the cost drops to the basic dyno tuning rate. Most basic fuel tuning takes at least 1.5 hr. Basic dynoing, meaning an average of 3 dyno runs or pulls to get your hp/torque curve in 3rd or 4th gear (preferably 4th since it's the closest one to a 1:1 gear ratio) and a coastdown run to get your drivetrain losses (which isn't all that accurate anyway), will cost you around $65-75/hr. The 3 runs take 35-45 min.
Obviously group or club rates where the dyno is tied up for the entire day by a group will cost less. Look for a local club who is organizing a dyno day...you may save. This is usually for basic dyno runs only and not tuning.
most people agree that in FWD cars the drivetrain losses are much less than the often quoted 20% you hear for the RWD domestics. They average around 15% for us. The range is 12-16%.
So for 130 whp ,multiply by 1.15 and you get the crank or flywheel hp...150 hp. but then again, we don't just focus in on the peak number, right?....