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Stock horsepower variance???

2K views 7 replies 7 participants last post by  Nissan-SR20-Man 
#1 ·
How much can the horsepower vary across the same platform???

IE are all Hemi's within 1-2 horsepower of each other? 3-5? 5-10? 10-20?

Reason I ask is I would like to dyno my car with the volant to see some numbers... Without a baseline for my car is it pointless to dyno to see if there are any gains??
 
#4 ·
I would disconnect the battery after each swap and give it a few days before testing each time if possible.

Looking forward to seeing the actual gains - thanks for doing this!
 
#7 ·
Put the stock intake back on. drive for a few days, go to dyno and get stock numbers. then put CIA on and dyno again (same day, same dyno, within a hour of eachother or so).

In all honesty it won't be worth the cost of the dyno time as you will only see a small difference.
 
#8 · (Edited)
Understand what you are asking in your statement. My opinion of your problem is to use the same dyno, before and after mods for the best differential results. If it was me, I would dyno on the same day as close as possible to remove the most variables. Stock, then mod intake. This yields the best "real" differential measurement. You really don't care what is before or after, you care the most about the difference or the amount gained

Are the HP's identical?

At the factory there is supreme process control regarding the engine operation, dyno torque measurements, calibrations, etc...

When you leave the factory, you introduce so many variables, your percentage of accuracy goes through the roof. Meaning, my WK2 dyno'd on 100 dyno's would make 100 different readings due to different measurement devices and multiple calibration methods, etc...

In my opinion, I believe the factory could test +/- 1% of rated torque (hp calculated from TQ). I doubt any dyno operator (dude with a dyno) actually calibrates his measurement instruments, keeps certificates of calibration let alone properly maintains it.

I can test a 40,000 HP +/- .75% torque measurement on a dyno using scientific instruments, and guarantee it to ASME standards. Our equipment requires 3 hours of maintenance for every hour of use.
 
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