Sup guys, thought you could help with a small issue in finding out what I need to do. Here is a vid of my startup.

LNF start noise - YouTube

 

Did you just do some valvetrain work? Or just the turbo swap?

 

if anything the spot we log goes slightly uphill

 

Just turbo swap. Cams were done in early March. Have any ideas?

 

You def need that chain tensioner thingy done. That's what that terrible racket is you hear on startup. Check out this thread...

https://www.cobaltss.net/forums/08-1...art-up-267514/

You do have some loud ticking while the engine runs that sounds abnormal to me. Mine will tick kinda loud for maybe 40 seconds and then it settles. Yours was going up and down as you hit and released the throttle. Have you popped the valve cover off? Take a look and see if anything is funky in there.

 

Thanks Frog, good info.

Hopefully you can hear it better in this video. Excuse the shakiness, I was drving and filming.

http://www.youtube.com/watch?v=9XAFqcI3iAg&feature=plcp

 

He rolled into it starting at 55-56 MPH like we have always done on our 60-100 testing. The ETC has some lag as does the turbo even the stock turbo so this takes that lag out of the equation. His car ran 4.2 seconds 60-100 on the stock turbo using the same method. Actually if you look up the 60-100 times they have a list of cars but they take the 0-60 time and subtract it from 0-100 time to get the 60-100 of various cars so in that case they are full head of seam rolling into it with tons of momentum. Using that method the 60-100 of a C6 Z06 is only a couple tenth faster than forty's time and I am willing to bet if he went from a dig to 100 and I took the 60-100 that way it would come out about 3.4-3.5 seconds.

 

Very impressive but remember the sky has to rev to 7300 rpms in 3rd to get to 100 vs 6200 rpms on a Cobalt and with the power drop off on the stock turbo or even the BNR that same run would be far slower in a sky vs your cobalt. He ran a clean 4.2 60-100 on the stock turbo on E-85 with the cams.

Side note you should really raise your fuel pressure so you lower than IPW in the midrange because 8.1 Ms is a long injection time even at only 4000 RPMs. Raising Forty's pressure to 2500 psi reduced IPW by over 2 Ms in the midrange and about 1.5 Ms up top. I also have his injection angle pretty much maxed out at 385-415* depending on RPM.

 

wow, very interesting..
i wish mine was that fast...lol

 

That's BS is what it is. I would do 60mph and then punch it. No rolling into anything. Cheating bastards.

 

I remember the old days when I moved a paltry 34lbs of air on logs lol

 

paltry lol

 

E-47 makes a huge difference. On 91 octane and stock turbo forty was running in the 5.5 second 60-100 range. E-47 and no cams he was running 4.8 second 60-100 times. Cams and E-47 or E-85 4.2 second 60-100 times (cams allowed me to be more aggressive with the boost ramp in the midrange to the tune of a 1.5 second 60-80 time). All tunes were 24-25 psi max tapering off to 16 psi by 7300 RPMs.

 

nice...my car has been basically been sitting since my clutch is so bad. ive been talking about it forever now, so hopefully it will be installed soon, then i will see what my 60-100 is..maybe ill buy the dashboss for my ipad to get the numbers...lol

 

Nope even when he was on full E-85 and stock turbo at 24psi it would not take more than 21* up top and 17* midrange now matter what I tried I even lowered boost a little still would show knock on the logs.

 

knocking on e85? no matter what i do to my car, i can't get it to knock on e85

 

Your best 60-100 thus far was 5.2 seconds on 93 octane and your current 24 psi tune. The first tune was 5.3 seconds 60-100. E-47 you could hit 4.4-4.6 seconds easily.

 

Seems to hate timing more since the cams but I never could get more than 20* out of it on E-47. It made 368 whp and 446 wrtq stock turbo on 24 psi peak boost, E-85, cams and only 20* of peak timing and 14* in the midrange.

 

lol.... definitely no down hill runs here. If anything the spot where I normally start my runs is on a slight incline and flattens out quite nicely. Maybe I should find a nice hill and hit a solid sub 4 second pull and really annoy Frogstofall....

Wow, mine is definitely considerably less aggressive than that. I'm sitting around 330-360* mid range to top end. Do you think I should bump up my low and high tables a bit?

As far as fuel pressure goes, I actually used to command 2400psi across the board wot but I was seeing a pretty substantial pressure drop in the 3-4k range (1200psi actual rail pressure while commanding 2400). James had actually at one point suggested to try ramping in pressure a bit more and it honestly did seem to help out quite a bit with maintaining my commanded pressure closer to the 1900-2000psi mark. Maybe I'll try messing with it again and see if I can maintain pressure and keep my pulse widths down a bit. This is also partly why I'm trying to not push my injection angles too much further.

hahahaha.... I'll do a true 60-100 pull just for you if you'd like sweet heart.. jk man.. lol

Term2 does have a point though. After doing some more research I found that the standard does seem to be clocking/logging a 0-100 time and getting a 60-100 from that. Trust me man, for the longest time I was a dummy chasing my tail trying to figure out why the **** my 60-100 times were so much slower than alot of other cars with similar mods.... apparently I was actually ultimately faster when finally jumping on the waggon comparing apples to apples.. lol

and? A 410whp cobalt I tuned was only pushing 37lbs/min so I'm not sure what your point here is. Plus my 34-35lbs/min car is only 2 tenths slower 60-100 than 40rty's 44lbs/min car (sorry I'm not picking on you 40rty, I'm just using you as an example right now).

How much did the cams actually seem to help with his setup just out of curiosity? Aside from the obvious larger fuel pump lobe are they even worth it in the end in your oppinion or is a 5th injector ultimately enough in itself?

 

I didn't understand all that 60-100 mess until Tom told me about it, either. I, too, imagined it meant to stomp on it at 60 and measure the time it takes to get to 100. Tom told me to stomp on it at 50 and measure the 60-100 time and I got 4.8 secs with at 21 psi E47 tune.

 

Why couldn't this 60-100 BS come up a week ago? You all woulda seen a 3.5 sec time from me.

 

You don't have any old 3k-redline wot logs kickin around that you could pull a 60-100 from?

 

I wasnt getting at anything just remembering my stock turbo tc tuned on e47. I didnt realize alot of people on this site consider "the" and "if" big words.

 

my tvs on the stock block and head was flowing 40lbs per min lol.

 

I probably do but none are clean bc of wheel spin. Wheel spin ruins everything.