aka_Matt

notice how it was still pulling at the 6500 limiter, i bet it would hit 225 if let go to 7000...

zinner

Thanx for the video and dyno sheet guys. When you put in the K&N filter did you have to remove the air box to do it or did you just remove the 4 screws (rusted all to hell on mine) on the bottom of the air filter ? I was considering hacking off the air box and getting some ducting and a universal K&N filter, instead of waiting for someone to do it for me

zinner

Also have you guys hooked any OBD 2 monitoring systems up to the SS/SC? Are they still OBD 2 or the CAN only.

White_Zzzzz

Was this run done on 94 octane?

Also curious why no 4th gear runs were done.

Zefhix

Actually, RWD losses are closer to 17% on muscle cars and 13-15 on newer vehicles (lighter materials, tighter clearances) A FWD shouldn't see more than 10% especially on the SS/SC with the equal length halfshafts. You can't base you math around those dyno numbers because he wasn't at a real 1:1 ratio. The gears multiply HP and Torque and sometimes even reduce them (depending on the gear). Even when your at 1:1 every dyno is different. Mustang dynos are typically more accurate but show up to 20HP/TQ less than a dynojet would, so some dyno queens don't like them. I'll tell you what, though, those G-Techs are really accurate and useful in determining your actual dyno numbers because they use accelerometers instead of rollers with corrected resistace. Those little gadjets are worth every bit of their $300 price tag.

Archplsm

I was just thinking a little...... if we are talking 217hp at the wheel, one of the first mods that will have to be made is replacing the rods. If I remember right, the rods are only rated to 273 or 278 hp. This nmber can easily be reached with hp ratings like this from the factory. Does anyone know if Chevy has the replacement rods out yet and what they will run for the parts and install?

Dman

i think your thinking about the 2.2 where the rods failed at 280...remember this is a differently built block...its got rods a pistons from the factory...id dig up the thread that explains all of this but man, im lazy...

zinner

1st gear is 4.05
2nd gear is 2.02
3rd gear is 1.35
4th gear is 0.98
5th gear is 0.69

Off the GM website.
http://www.chevrolet.com/cobalt/specifications/

Archplsm

yeah that's right Dman.... it's the 2.2 that fails

Vendian

I wish I could find that article on the 2.2 again. Does anyone know where to find it?

Archplsm

Vendian. I found it by searching the site with "rods breaking" in the seach engine

jerm

iTrader: (1)

Wow zinner; GM must have determined that we'd all take out that box since they didn't rust-proof its screws.

theBLUEone

Awesome I can't wait until my SS comes in!!! So the SS's are seeing pretty good hp/tq numbers stock thats a good thing!

White_Zzzzz

So if Im reading this correctly, 4th gear would have given more accurate dyno results? I wouldnt think it would be too far off, probably around the same as the ION ~ 210whp.

Modern, any chance of doing some 4th gear pulls for us?

stuffy236

IIRC, i dont think the gear matters all too much. That the dyno measures how the car overcomes the load given by the dyno. The difference in gears would only mean a hp or two difference either way and that is about the same difference you would get from pull to pull. Very negligable.

mchat

Yup, we've done many pulls with SRT-4 in 3rd and 4th with minimal difference between gears (on some cars w/ mods 4th was actually higher than 3rd). We tend to dyno in 3rd tho, because 4th gets a bit choppy. Might be the same w/ the SS.

CobaltSS313

Would it be a problem if you could do a dyno in 4th gear and let us see the results...just to see if there really is a difference.

White_Zzzzz

Yup that is true about the choppy dynoes. What octane was used? 94?

stuffy236

also, since youre not making a whole lot of power (not a diss) then running in 4th may put too much strain on the engine since itll take longer for it to red line than in 3rd gear.

Zefhix

Well, it makes a big difference on the 400HP+ I run on the dynos all the time. We've seen differences of 50HP between 3rd(1.35:1), 4th(1:1) and 5th(.84:1) on a t56 6speed. Also, sure a dyno is a measure of resistance but gears are there to multiply and reduce torque/HP. Careful about the variances....

aka_Matt

once again, the GM site is wrong... these r the correct ratios/overall:

1st: 3.38/13.69
2nd: 1.76/7.13
3rd: 1.18/4.78
4th: .89/3.60
5th: .70/2.84

zinner

How did you come up with the numbers ? Just curious I will be the first to say the GM site can be wrong

elpaso

well ALL Dyno must be performed out on the 4th gear unless specified by the dyno testers.

aka_Matt

i don't remember where i found it, 1 of the inside type sites... just now i found it on here, i knew i posted it before...

mchat

91, best we can get at the pump here in Az.

On a couple of the runs I kept an eye on the knock meter on the D-Tec. Some of the chopiness is because of how rich the car runs...