No BS dyno test of Vararam CAI for G8

[Patrick G]

Low LSA

Not exactly. You can have huge overlap with a wide LSA cam and lots of duration. A 224/224 110LSA cam has 4 degrees of overlap at .050" while a 232/238 114LSA has 7 degrees of overlap. See how it works? Wider LSA, but still more overlap. You can't make a blanket statement about overlap and LSA. You have to include duration.

[dandragonrage]

[GM_Fan]

What kind of MPG are you getting and at what speed?

I can eeek out 28-29mpg at 55mph on a long flat stretch. It quickly goes down when I get on the Interstate at 70mph. Then I'm lucky to see 22-23mpg. According to the DIC.

I'm really interested to see what cam profile can still give good performance and still run on 4 cylinders while just cruising.

[dandragonrage]

What about for those people that go ~85 on the highway? Not that I'm implicating anyone here or anything....

[GM_Fan]

What about for those people that go ~85 on the highway? Not that I'm implicating anyone here or anything....

If you are going 85 you probably aren't worried about fuel mileage much.

I was asking about 70mph because that's the upper speed limit for Interstate traffic in my state. Maybe I should ask about 65mph if that the national average of Interstate traffic.

EDIT: I read more and did find out what I was looking for.

With my tuning tweaks, I can cruise in 4 cylinder mode at 75mph in the G8. I knocked down 26mpg on a trip to Texarkana last week. A solid 2 mpg better than the EPA highway rating. My around town mileage is 16 which is around what the Jeep would get on the highway, haha.

[Patrick G]

I finally had a chance to log the MAP numbers of the stock airbox vs the Vararam on the dyno and at speed. Here are the findings:

Stock Air box:
kPa would drop from 101 to 96kPa at WOT on the dyno and at speeds of over 100mph. No ram air effect.

Vararam:
kPa would drop from 101 to 98kPA at WOT on the dyno. (2 kPa better than stock).
kPa would hover between 99-100kPa at speeds above 60mph with an occasional 101kPA. (4-5 kPa better than stock).

Net result, the Vararam gave 2 kPa less restriction on the chassis dyno vs. the stock air box and added an additional 2-3 kPa in pressure at speeds above 60 mph. Since we gained around 10rwhp on the dyno with a 2kPa gain, it is possible to pick up a total of 20rwhp over the stock airbox at speeds over 60mph considering the 4-5kPa gain of the VR vs. stock.

[GRRRR8]

Thanks for the info Patrick.

[johnh]

Great info Thanks.

[Ktlplxm]

If you are going 85 you probably aren't worried about fuel mileage much.

I was asking about 70mph because that's the upper speed limit for Interstate traffic in my state. Maybe I should ask about 65mph if that the national average of Interstate traffic.

EDIT: I read more and did find out what I was looking for.

I have an Ed Curtis cam extremely similar to the New Era non DOD cam. In my car @ 70-75 mph I still can maintain 27mpg. It could potentially be higher, but I do have another full liter worth of engine to feed with fuel. I believe the cam is 228/240 with a .600/.600 on a 114.

[johnbell2]

Not exactly. You can have huge overlap with a wide LSA cam and lots of duration. A 224/224 110LSA cam has 4 degrees of overlap at .050" while a 232/238 114LSA has 7 degrees of overlap. See how it works? Wider LSA, but still more overlap. You can't make a blanket statement about overlap and LSA. You have to include duration.

You have to include duration so that you know how long both the intake and exhaust valves are open at the same time (hence, overlap), correct? Maybe it's obvious but I'm new to all this...