Aem Short Ram Dyno - Before & After

[Woody]

The attached below is a before and after of my P5 with a AEM Short ram as my only mod.

To be fair, the after should be about 1 to 3 hp higher throughout the curve. This is because the "after" dyno was done in weather that was about 20 degrees hotter (80 degrees F) and in farily humid weather (75% humidity). My dyno guys said that dynoing in hot weather can make up to 5 hp diference (less hp) than one on a cooler day. But my engine was fully hot on both test days, but again the outside temperature was quite a bit hotter today for the after run.

So as is without any compensation for weather, the max positive impact was 5.1 hp toward the top end of the power curve. Compensating for the hot weather, my conservative estimates would be that the lower end of the power curve with the AEM would be in line or possiblly 1 to 2 hp over stock until about roughly 1/2 the way up the power curve and then the hp would climb to an adjusted increse of roughly 4 to 5 hp over stock. By the way, my dyno guys could not get torque numbers because they were getting false rev numbers from the P5 system.

All in all - I was my seat of the pants estimate was right - the AEM Short Ram DOES increase hp, espeacially in the high end of the power curve.

- Woody

 

[Carl]

That's not a bad increase for $40/hp. It has less restriction versus the length of the CAIs. The only thing I don't dig on with the short ram is hotter air is getting into the intake versus cold air stock or CAIs (so says a thread on here).

I've yet to use the G-tech with 87.

I'm going to be in Minneapolis for the 4th. Maybe I'll see your screaming yellow zonker wagon before you see my low profile black mica 5.

 

[mazdamp3_18]

i think 5 hp is on the high end.... i dynoed my car and i have a short ram and a custom manifold to muffler exhaust .... no 2nd cat and no resonator and 2.25 inch piping .... i gained 4 hp and 11 lbft

 

[Woody]

Carl,

Sure, why don't you give me a ring if you are in town July 4th - my home phone is 763/529-1413. And yes, Intake is biggest bang per buck - that is probably why most guys do it as their first mod.

Mazdamp,

Not sure why you got a bit lower benefit than I did. But from the dyno I posted, 5.1 was the MAX benefit. It will very over different points of the power-curve. If you don't adjust for heat and humidity, I actually lost a bit on the low end of the curve. Its an in-exact science, but I still think an adjusted power curve would run between 2 to 4 (possiblly 2 to 5.5) over most of the curve.
The only way to be sure would be to re-dyno on a day that is around 60 degrees F, and low humidity, but I may not get cooler weather like this until fall.

- Woody

 

[ArkosP5]

Question:

Looking at the chart (and driving my car) I notice that the curve on the chart is not quite smooth, it has waves to it (which I seem to notice under hard acceleration). Does anyone know why it does this? I haven't seen a LOT of dyno's in my life, but from the few I remember seeing of other cars, the curve itself is much smoother (straighter line). Is this something that can be fixed?

 

[Woody]

Arkos,

I'm not a pro, but my guess is that the bigger dips have to do with carbueration, or in our case fuel injection maps. If carburation (fuel mappings) were perfect, I would expect the curve would have no dips at all.

I've seen atleast some small dips in all dyno graphs I've ever seen, including sport-bikes. For me the key beyond how much hp/torque is produced, is first to see the SHAPE of the curve (ideal is to keep building until the rev lmiter chokes back the engine at the very top end of the curve) then to see how many dips there are, and how pronounced the dips are.

I actaully think the power curve is really good on the P5, (except it stops at 105 hp, and not 195 - Ha!). I have seen some curves, like the new Honda Si, that have a huge dip in the middle - so you get a real nasty drop off in acceleration around 3 to 4,500 rpm.

I'll be curious to see what more technicial guys have to say about this.

- Woody

 

[vegasmp3]

That sound about right for the power you got......Mazdamp3 by eliminating the resenator does not add any horsepower.....dont let them fool you...all it adds is a louder sound........upping your piping to 2.25 will help you out along with the short ram.....

 

[mazdamp3_18]

vegas i also took out my cat... the piping should help a little but not alot...i know a resonator wont help other than be louder... maybe they werent getting a good reading on the rpm... b.c my curve had not huge dips or anything like that ..it was all a smooth power band.... except for the .5-1.5 dip when the manifold switches over to the shorter run.... but its only for a short ammount....

 

[brain]

Was that 8200rpm you revved out too???



Holy sheepshits

 

[mazdamp3_18]

the rpms were messed up....