I'm still waiting on my own stage 2, but I've noticed some people claiming slight power decreases at low rpm. The following link gives some data on the 4th gen Eaton M62 (ours is 5th gen, so should be close):

http://www.capa.com.au/eaton_mp62_4th.htm

It occurred to me that the power loss could be due to the higher HP requirements of the smaller-pulley supercharger. You can see on the graph that 5 extra psi = ~5-10 extra HP required. So, 12.5 --> 15psi (approx) change from Stage 2 would rob the drivetrain of at least ~5 extra HP during low-rpm "spooling." This may also help to explain the small HP increase from the smaller pulley (torque is another story though). However, bigger injectors and reflash may minimize this.

Another possibility - the perceived upper-end power increase may obfuscate your perception of the lower-end --> stage 2 makes supercharger lag (although minimal) more noticeable. (I hope this is the case!)

Just my humble opinion...

 

 

you are most likely correct, good find and analysis.

 

Link is fixed.....oops!

 

yup. I think

 

Do you think you could even notice the loss of 5 HP at low rpm's ? I think low rpm torque loss would be noticed first.

 

Supercharger lag? Lol. We don't have turbos. There is no such thing.

The SC boosts as soon as the bypass valve is closed.

 

Never Felt your SC bog down at 2500 RPMS?

 

SC get lag but only for a couple seconds. I thought it would hurt the low end but to my surprise it feels better than before.

 

Yeah, I think you are more right in saying that. (although, of course, the hp vs. torque debate need not be revived here )

Also, superchargers do have a "lag" because they always spin proportionally with the crank. (i think ours with stock pulley gives a crank_rpm:supercharger_rpm ratio of about 1:2) Max boost comes from max supercharger_rpm (duh?) which arrives at max crank_rpm. (You can see in the graphs from the Eaton spec link that their tests conspicuously stop at 16,000 supercharger_rpm) Confirmation of this could come from someone with 7k redline and stock pulley (Stage 1). Max Boost on Stage 1 might (should?) be higher at 7k than stock.

Drive safely!

 

True, True.

 

you are right, however, with a stage 1, and a stock pully, the computer i would think would remain the same as far as controlling the boost, they up the redline a little yes, but unless you do either the boost bypass, or a smaller pully, i would think the boost would still remain at 12.5...... im by no means an expert, but that is just my thaught on the matter

 

oops. quoted the wrong post, sorry leafy, i meant to qoute the one you did...

 

VERY good point - I wonder if the Stage 1 flash changes the max boost tolerance. hmmmm - someone with stage 1 needs to put this one to rest.