How about those ford cj's at vegas

Evan Smith · 10-31-2009, 10:22 AM

Steve,

Can I assume that you've measured the differences at different boost levels in order to report these findings? In theory you are right, but we are talking about small changes in boost level from good air to bad air. Probably 3-4 psi on the CJs from sea level to Vegas. The cost to drive the blower for that extra 3-4 psi is very, very small.

I've tested over 100 blower cars with all types of blowers over the years and while I've not measured crank hp, save for one time on a 1,200 hp engine, I can tell you the loss in power from adding a few pounds of boost is not a lot. In that case it took upwards of 250 hp to run the blower. I would guess a change in boost, even at that level, would have very little effect on overall power loss/gain. Again, in theory you are right, but in practice the gain/loss is not what you think.

Most blower engines are designed to run with boost pressure so even if you removed the blower it wouldn't give you a fair result on power because the engine would likely be inefficient with no boost.

Evan

10-31-2009, 10:22 AM	#11
Evan Smith Member Join Date: Nov 2001 Location: Tampa Posts: 400 Likes: 7 Liked 115 Times in 5 Posts	Re: How about those ford cj's at vegas Steve, Can I assume that you've measured the differences at different boost levels in order to report these findings? In theory you are right, but we are talking about small changes in boost level from good air to bad air. Probably 3-4 psi on the CJs from sea level to Vegas. The cost to drive the blower for that extra 3-4 psi is very, very small. I've tested over 100 blower cars with all types of blowers over the years and while I've not measured crank hp, save for one time on a 1,200 hp engine, I can tell you the loss in power from adding a few pounds of boost is not a lot. In that case it took upwards of 250 hp to run the blower. I would guess a change in boost, even at that level, would have very little effect on overall power loss/gain. Again, in theory you are right, but in practice the gain/loss is not what you think. Most blower engines are designed to run with boost pressure so even if you removed the blower it wouldn't give you a fair result on power because the engine would likely be inefficient with no boost. Evan __________________ Evan Smith 1798 STK