CAI Dyno Sheet

[rottenronnie]

My QC ran consistant 13.7-13.8 1/4 miles stock and so far a best of 14.3 with the K&N FIPK kit. I have not removed it yet in hopes that with the addition of a programmer I can improve the results.

Look at your M.P.H. instead of your e.t. You may have increased power and lost e.t. due to tire spin, for example, in your case.
M.P.H. can indicate an increase or decrease in power and is a far better tool than e.t. for measuring changes in performance.

 

[rottenronnie]

I own a dyno shop and we get this kind of thing all the time. It appears that you are quoting an increase or a decrease in “peak” power. That really doesn’t tell you if there is a usable performance increase/decrease or not. A CAI may or may not help performance in a particular rpm range. In other words, you could lose a few peak horsepower and still have improved performance. You have to look at the entire power curve. Where exactly are the increases and decreases? What are you using the vehicle for? What is the optimum rpm range for that usage, i.e. 1/4 mile drag racing, 1/8 mile drag racing, road racing, top speed, street cruisin’, etc. Is there more power in that particular range? That’s where you need to focus your attention. Also, does power come on earlier and/or stay on later? For example, if torque comes on stronger at an earlier rpm, flattening out along the entire rpm range it could indicate more usable power and increased performance even though it may not peak quite as high overall.

Measuring the actual affect of a CAI on a stationary vehicle is difficult at best. Also, CAI intakes may or may not show any measurable increase in power but they may help you more consistantly maintain power on a warmer day than the stock intake or they might increase the intake volume of air when actually moving down the road. There may even not be much increase on a stock or near stock engine because the engine might not be set up to do anything with the increased flow. A CAI will do little good if the air is bottlenecking somewhere else in the system such as the valves or the exhaust manifolds. The benefits might be felt later as more modifications are added and the engine can actually use the extra air.

There are so many variables that you can’t just make a blanket statement that says it lost X amount of horsepower on a dyno so, therefore, the performance is down. Still the best way to measure the benefits of a CAI is to run it at the track over a long period of time keeping detailed logs of ets, temps and track conditions.

Thanks for the information.
It is interesting that K&N claimed a 19+ H.P. gain with the c.a.i. for the Ram SRT10. I wonder how they arrived at that number if not with a dyno?
Anyway, I hated the sound of the K&N (personal opinion) and I wouldn't have run it even if it GAINED power.
Yeah, the peak H.P. number throws some people off and they expect an 80 H.P. (peak) increase with a stage 2 flash, for example; which would be nice.
I like to think I can "feel" 10 horsepower with a butt dyno and the K&N, didn't seem to do a thing to improve performance in any r.p.m. range or driving style.
So, in this case, the dyno was all I had (and maybe all K&N had) to measure if it helped or hurt power. I fully understand what you mean about it not helping (perhaps) a near stock engine but may help on one more heavily modified, etc.
Perhaps K&N was blowing nitrous into the back of the fan during their dyno pulls to claim their 19.12 H.P. increase.
Thanks again for the info.
Ron

 

[Big Asp]

It is interesting that K&N claimed a 19+ H.P. gain with the c.a.i. for the Ram SRT10. I wonder how they arrived at that number if not with a dyno?

Excellent question! I'm sure they used some kind of dyno data but I am always very wary of any manufacturer's horsepower dyno claims because I know how easy it is to manipulate dyno results. A claim of 19 hp from a CAI seems to me a bit "generous" unless the stock set-up was extremely restricted.

Dynos are really best used as tools for tuning and as indicators that performance modifications are taking you in the right direction. For accurately comparing stock parts to modified parts or modified parts to modified parts, the test conditions have to be very carefully controlled. What's funny are the guys who come to our shop expecting to make huge amounts of power because they simply totaled up all of the different maunfactuers' horsepower increase claims for the parts they've added. They usually go away very disappointed.