Hiya boys and girls, I finally got my car dynoed today! I would post it, but I don't have a scanner (argh, never really had to use one so never bought one). If anybody's interested, here are the results (I'll have to describe it). First, the background info:
The dyno was a rather aged model 248C dynamometer. I did 5 runs, 3 stock except for my MHP CAI, 1 run with the muffler unbolted, and 1 run with the exhaust off up to the catalytic. I have exactly 5,000kms (not anymore, after today) on the car, and it's been through its first oil change at 4,000km. I'm using 94 Octane, which I had a full tank of today.
OK here we go:
The 3 runs with only the MHP intake were identical (almost). I had 114.3, 114.0, and 114.8 hp max, at approximately 6,000 rpm, and 119.1, 119.0, and 119.1 ft-lbs of torque at about 4,000 rpm.
Imagine this...the torque graph began at about 109 at 2,200 rpm, rising steadily to peak at 4,000, then declines at an increasing rate to 90ft-lbs at 6,500 rpm.
The horsepower graph is very steady, beginning at 43 or so at 2,250 rpm and rising very steadily to peak at 6,000, then falling off slowly towards redline to 111.
Now, there is one really interesting thing: both on the hp and torque graphs, a sharp dip occurs at 4,600 rpm consistently. Hp drops from 102 to 98, and torque dips from 112 to 108 suddenly, then at 4,800 rpm picks up again sharply, continuing the smooth line that was being drawn before the dip. Weird! I asked about this V shaped depression, and someone told me that perhaps the stock fuel regulator can't quite handle it and perhaps an aftermarket one would help. I dunno about that, sounds rather strange that a stock regulator can't handle a stock engine...
Anyways, moving on...point number two: the dyno guys told me that my motor was still too young at 5,000kms (3,000 miles) to get an accurate dyno reading. They said that one guy who brought in a stock motor at both 3,000 miles and 6,000 miles to do baselines actually got 6 hp more at the wheels when he ran in the motor further. at 3,000 the motor should be 'officially' run in, but a little more aging might be a good thing...
Point number 3; the regulars at the dyno told me that this old dyno that they've been using gives consistently 'conservative' results. On another dyno (out in the suburbs) the readings are almost always a couple hp/torque higher.
Who knows? I'll let y'all know when I dyno my car at 6,000 miles and at the other place! Maybe there'll be no diff, but then again they said it's likely I'd get 4 or 5 more hp. Nothing dramatic though. Overall I'm satisfied...140 hp at the crank with a 26 hp loss...that's about an 18.5% driveline loss.
But that's WITH the CAI. And it does make a difference! The reason I know: a stock Protege5 went in right before me, doing a completely stock pull of 102hp. They have 10hp less at the crank than we do, so that is about 8 hp at the wheels less. Doing the math, 114 - 102 - 8 = 4. Meaning, about 4 hp at the wheels gain, or 5ish at the crank. I really wish I had dynoed my own car before the CAI just to make sure, but damn dynos are expensive! For my experiments today I could have bought a handful of K&N's!! But it was all in fun though hehehe....
Heads up: the stock Protege5 put in a replacement K&N filter (yes, only the flat one!) and ran 105 hp...3 hp gain for a teeny mod like that! Now that's a cheap but effective mod! Hehe I paid almost $300 USD more than him, and got only 1-2 hp more out of my CAI...but then I am paying for both the looks and the intake roar too...
Oh, and for comparison, the Pro5 was fully run in, with (I can't remember, but something like 6-7 thousand km on it).
OK, as for the no-muffler and no-cat-back runs, I wanted to see if an aftermarket cat-back would be a big improvement so I wanted to try absolutely no restriction (unbolting the damn thing). On both runs, peak hp was down by 2, while torque remained the same. However, the torque graphs drop quicker after peak in the no-cat-back and no-muffler applications. On the hp graph, it's all the same until about 4,000 rpm, then the stock line and the no-exhaust lines begin diverging.
All in all, those guys told me that we have a great exhaust system stock, and that not much tuning can be done to it. So, heads up...if you do decide on a cat-back, make sure the tuner has real dyno results first. You just might end up losing power.
The physics of exhausts are very complex, and everybody's got a different opinion (I've read a lot and seen a lot, but I hesitate to post my theory) so you can draw your own conclusions.
It's definitely not as simple as 'less backpressure, more flow' being the key to hp in all applications! There's also the whole deal about resonance waves, and flow velocity, etc etc...hope somebody else except me is experimenting around here!
Sorry for the essay, but thought some people would like to know, and I've really got to buy a damn scanner...
The dyno was a rather aged model 248C dynamometer. I did 5 runs, 3 stock except for my MHP CAI, 1 run with the muffler unbolted, and 1 run with the exhaust off up to the catalytic. I have exactly 5,000kms (not anymore, after today) on the car, and it's been through its first oil change at 4,000km. I'm using 94 Octane, which I had a full tank of today.
OK here we go:
The 3 runs with only the MHP intake were identical (almost). I had 114.3, 114.0, and 114.8 hp max, at approximately 6,000 rpm, and 119.1, 119.0, and 119.1 ft-lbs of torque at about 4,000 rpm.
Imagine this...the torque graph began at about 109 at 2,200 rpm, rising steadily to peak at 4,000, then declines at an increasing rate to 90ft-lbs at 6,500 rpm.
The horsepower graph is very steady, beginning at 43 or so at 2,250 rpm and rising very steadily to peak at 6,000, then falling off slowly towards redline to 111.
Now, there is one really interesting thing: both on the hp and torque graphs, a sharp dip occurs at 4,600 rpm consistently. Hp drops from 102 to 98, and torque dips from 112 to 108 suddenly, then at 4,800 rpm picks up again sharply, continuing the smooth line that was being drawn before the dip. Weird! I asked about this V shaped depression, and someone told me that perhaps the stock fuel regulator can't quite handle it and perhaps an aftermarket one would help. I dunno about that, sounds rather strange that a stock regulator can't handle a stock engine...
Anyways, moving on...point number two: the dyno guys told me that my motor was still too young at 5,000kms (3,000 miles) to get an accurate dyno reading. They said that one guy who brought in a stock motor at both 3,000 miles and 6,000 miles to do baselines actually got 6 hp more at the wheels when he ran in the motor further. at 3,000 the motor should be 'officially' run in, but a little more aging might be a good thing...
Point number 3; the regulars at the dyno told me that this old dyno that they've been using gives consistently 'conservative' results. On another dyno (out in the suburbs) the readings are almost always a couple hp/torque higher.
Who knows? I'll let y'all know when I dyno my car at 6,000 miles and at the other place! Maybe there'll be no diff, but then again they said it's likely I'd get 4 or 5 more hp. Nothing dramatic though. Overall I'm satisfied...140 hp at the crank with a 26 hp loss...that's about an 18.5% driveline loss.
But that's WITH the CAI. And it does make a difference! The reason I know: a stock Protege5 went in right before me, doing a completely stock pull of 102hp. They have 10hp less at the crank than we do, so that is about 8 hp at the wheels less. Doing the math, 114 - 102 - 8 = 4. Meaning, about 4 hp at the wheels gain, or 5ish at the crank. I really wish I had dynoed my own car before the CAI just to make sure, but damn dynos are expensive! For my experiments today I could have bought a handful of K&N's!! But it was all in fun though hehehe....
Heads up: the stock Protege5 put in a replacement K&N filter (yes, only the flat one!) and ran 105 hp...3 hp gain for a teeny mod like that! Now that's a cheap but effective mod! Hehe I paid almost $300 USD more than him, and got only 1-2 hp more out of my CAI...but then I am paying for both the looks and the intake roar too...
Oh, and for comparison, the Pro5 was fully run in, with (I can't remember, but something like 6-7 thousand km on it).
OK, as for the no-muffler and no-cat-back runs, I wanted to see if an aftermarket cat-back would be a big improvement so I wanted to try absolutely no restriction (unbolting the damn thing). On both runs, peak hp was down by 2, while torque remained the same. However, the torque graphs drop quicker after peak in the no-cat-back and no-muffler applications. On the hp graph, it's all the same until about 4,000 rpm, then the stock line and the no-exhaust lines begin diverging.
All in all, those guys told me that we have a great exhaust system stock, and that not much tuning can be done to it. So, heads up...if you do decide on a cat-back, make sure the tuner has real dyno results first. You just might end up losing power.
The physics of exhausts are very complex, and everybody's got a different opinion (I've read a lot and seen a lot, but I hesitate to post my theory) so you can draw your own conclusions.
It's definitely not as simple as 'less backpressure, more flow' being the key to hp in all applications! There's also the whole deal about resonance waves, and flow velocity, etc etc...hope somebody else except me is experimenting around here!
Sorry for the essay, but thought some people would like to know, and I've really got to buy a damn scanner...
I know it sucks. But not much we can do about it. They will tell you the power at the crank for the most part just because it's higher.
