Stage kit first impressions
01-27-2009, 09:02 AM
#1
Senior Member
Thread Starter
Join Date: 03-16-2008
Location: Cleveland, Ohio
Posts: 662
Stage kit first impressions
My kit was installed at Tim Lally Chevrolet in Cleveland. They did a fine job, and honored the recommended labor time. They're a good dealer, and sell and service more Corvettes than anyone else in the area. Their people are accustomed to performance minded customers.
Well, the 'ol butt dyno says the kit is a good deal. I have Blizzaks on the car right now and am unable to see how much boost is available because I run out of traction before I run out of boost. Nonetheless, it does go above 2 bar, so the new sensors are doing their job. Actually, it would brush up against 20 Lb before the traction nanny kicked in. I'll look forward to seeing how she performs with the summer tires.
I drive the same 25 mile commute every day, and the "inst mpg" indicator seems to be saying I'm getting a little better fuel economy. I'm sure the new calibration involves more than just a different wastegate table, and I imagine changes to cam, ignition, and injector timing are probably why the economy is a little better. This DI and VVT thing is pretty new, so I suspect the rules are still being written to a degree (no pun intended)
Anyhow, my hat's off to the fellows at Powertrain and GMPP for a job well done.
Well, the 'ol butt dyno says the kit is a good deal. I have Blizzaks on the car right now and am unable to see how much boost is available because I run out of traction before I run out of boost. Nonetheless, it does go above 2 bar, so the new sensors are doing their job. Actually, it would brush up against 20 Lb before the traction nanny kicked in. I'll look forward to seeing how she performs with the summer tires.
I drive the same 25 mile commute every day, and the "inst mpg" indicator seems to be saying I'm getting a little better fuel economy. I'm sure the new calibration involves more than just a different wastegate table, and I imagine changes to cam, ignition, and injector timing are probably why the economy is a little better. This DI and VVT thing is pretty new, so I suspect the rules are still being written to a degree (no pun intended)
Anyhow, my hat's off to the fellows at Powertrain and GMPP for a job well done.
01-27-2009, 04:55 PM
#3
Senior Member
Join Date: 07-31-2007
Location: MI
Posts: 101
Well, the 'ol butt dyno says the kit is a good deal. I have Blizzaks on the car right now and am unable to see how much boost is available because I run out of traction before I run out of boost. Nonetheless, it does go above 2 bar, so the new sensors are doing their job. Actually, it would brush up against 20 Lb before the traction nanny kicked in. I'll look forward to seeing how she performs with the summer tires.
[QUOTE]
Do U have 5 spd or auto??
I have a 5 spd with Blizzaks and had a aftermarket tune before the GM Stage
tune and there is a difference. The Blizzaks are hopeless with the aftermarket
tune cause it has more low speed boost designed in. The GM tune will still turn them over in lower gears and now that the weather is better I can map
out the boost response of GM kit better. As Bill has noted, the boost above
3000 is not limited but I do see a difference. The GM stage gives me 16-18
psi from 3000 to about 5000 rpm at which it rapidly rises to 21 or so psi.
The feel is similar to a cam coming in at 5000 rpm.
If yours is an automatic, do u see a similar rise in boost at the higher rpms??
turbofreak
[QUOTE]
Do U have 5 spd or auto??
I have a 5 spd with Blizzaks and had a aftermarket tune before the GM Stage
tune and there is a difference. The Blizzaks are hopeless with the aftermarket
tune cause it has more low speed boost designed in. The GM tune will still turn them over in lower gears and now that the weather is better I can map
out the boost response of GM kit better. As Bill has noted, the boost above
3000 is not limited but I do see a difference. The GM stage gives me 16-18
psi from 3000 to about 5000 rpm at which it rapidly rises to 21 or so psi.
The feel is similar to a cam coming in at 5000 rpm.
If yours is an automatic, do u see a similar rise in boost at the higher rpms??
turbofreak
01-28-2009, 07:40 AM
#6
Senior Member
Thread Starter
Join Date: 03-16-2008
Location: Cleveland, Ohio
Posts: 662
Do U have 5 spd or auto??
I have a 5 spd with Blizzaks and had a aftermarket tune before the GM Stage
tune and there is a difference. The Blizzaks are hopeless with the aftermarket
tune cause it has more low speed boost designed in. The GM tune will still turn them over in lower gears and now that the weather is better I can map
out the boost response of GM kit better. As Bill has noted, the boost above
3000 is not limited but I do see a difference. The GM stage gives me 16-18
psi from 3000 to about 5000 rpm at which it rapidly rises to 21 or so psi.
The feel is similar to a cam coming in at 5000 rpm.
If yours is an automatic, do u see a similar rise in boost at the higher rpms??
turbofreak
01-28-2009, 04:23 PM
#8
Senior Member
Join Date: 06-27-2006
Location: Kingsville On
Posts: 732
I don`t think so but it`s not my motor
http://wiki.answers.com/Q/1bar_is_eq...o_how_many_psi
http://www.answers.com/topic/atmospheric-pressure
01-29-2009, 06:25 AM
#9
Senior Member
Thread Starter
Join Date: 03-16-2008
Location: Cleveland, Ohio
Posts: 662
The problem with your reference is that you're thinking in terms of gauge pressure as opposed to absolute pressure. Map sensors read absolute pressure referenced to a perfect vacuum as zero. It's the "A" in MAP. Gauge pressure is referenced to whatever the atmospheric pressure happens to be, typically 98-100 kPa. A 2 har sensor is capable of reading 2 bars above absolute vacuum, which is about 1 bar above normal atmosphere.
