HOw much are my heavy 17"'s costing me on the dyno? I can not get an exact number but any ideas.

 

17" isn't too bad since stock is usually 15"-17". Actually the tires are the most important weight since they're the farthest from the hub. In acceleration each lb of additional wheel/tire weight usually equals 8lbs static weight.

Figure out your weight and compare vs stock to begin.

 

Larger/heavier rims are definitely going to hurt you, although it might not necessarily show up on the dyno. Some have dynoed claiming adding big rims made no difference. Others have dynoed claiming they lost a bunch of power. The added mass and resulting inertial resistance to acceleration of the big rims will most definitely hurt your acceleration, though.

 

I wonder if this is partially responsible for a 20hp/20tq decrease since my last dyno. I've added the full 2.5" exhaust, CAI, and tuned it, however I've gone from 15 inch winter steelies back to my 17x8 CSA's+245/45ZR17 S-03's... up until now, I was thinking of it as a dyno thing.

 

Yeah,That may be why I'm missing around 20hp as well Time to dyno with the 15" steelies but I just got the g-tech pro so I'm going to mess around with that and see if it gives me numbers that make me happy

 

What were your dyno numbers?

 

I got 196hp and 192 ft-lbs of torque
Hey you never got back to me about the stuff you're selling

 

Those numbers are not low. They are right on based on your mods.
Will PM u now.

 

They are right if you don't have a UDP or a lightened flywheel.
Compare with a33. I don't seem to be getting any gain from those 2 mods on the dyno but I can definitely feel a difference from the lightened flywheel and I've seen better dyno numbers.
No worries though if the numbers don't get better I may be going forced air

 

Remember those to mods in question are not really for peak numbers but should give you better average numbers. ie. More power throughout the curve. Your numbers are right on so no worries and don't get caught into dyno racing. Put your stock cat back on and sell your RT cat. Get some low end back.

You have pretty much every bolt on mod. You must go to the track a lot? What are your 1/4 times, 60fts and traps? Those are the bottomline numbers you should worry about.

 

Items that reduce rotational inertia will have the greatest effect when the rotational acceleration is the highest. That would normally be 1st gear and the noticeable gain decreases the slower the rotational acceleration. On a dyno in 3rd or 4th gear the effect is fairly low and may not show up much. In reality through 1st and 2nd there is probably a gain, but due to the way dyno testing is done, it can’t be measured easily.

 

What maximumhp says is correct. You won't see the effect of a lightened flywheel on a dyno.