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Discussion Starter · #1 · (Edited)
Just installed Pulley Technologies 2.85" pulley. I found these guys off of ebay they are selling these for $55. They also hooked me up with a tensioner because when you go below 3.00 pulley the belt gets alittle lose. Anyway I will get down to it. Took about 10mins to get the blower off and on the bench I used a tool we made to remove and put the pulley back on this took about 30mins to do because we took our time not to mess the blower snout up. Another 10mins to hook it back up total time under a hour but this is at a professional tuner shop. Anyway I already had baseline runs on my SS on my own dynojet and the best I could get was 215/192 and I thought that was good. I test drove the car after the pulley and BAMMM hit 10psi in a blink and 12 on the next blink in 2seconds I was running :eek: 15psi on my gauge all the way to redline. My car use to run at around 10-11 maybe tap 12 for a second before redline but really about 10-11 after some buildup time. I was alittle worried after the test drive about the AF ratio so I went right to the dyno and strapper her down with a AF Bung. Made the pull and I was real happy 237/217(242/221 if I took the smoothing off the dyno) and the area under was BADASS in some spots I was making over 35 more RWTQ than before. AF ratio across the pull was in the 12.5 range and never went above 12.9 even at above 6,300RPMS. The AF was mostly in the 12.5 across the board. I am not sure if this is to lean for these motors but I am glad it is not running in the 14's or someshit. The car is stock except for this mod. I spent 55 on the pulley and 75 on the tensioner. Needless to say the car drives great especially on the bottom end and midrange. I will post the before and after dyno sheet if I can figure it out or if someone can do it for me I will send it to them.

Sorry for the long post but since there is little info on pulley, AF, and dynos I thought I should tell everything.

Looking to get her over 250 with a few other changes ;) I'll let you guys know.
 

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do you have a mechanical gauge installed ...it was my understanding that the gauge dosent show more than 12 psi ...and what have you done to the PCM so that your not getting CEL ect
 

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Discussion Starter · #5 ·
c7015 said:
do you have a mechanical gauge installed ...it was my understanding that the gauge dosent show more than 12 psi ...and what have you done to the PCM so that your not getting CEL ect
Stock gauge and it does hit 15psi and maybe alittle more close to redline. I know these gauges are not mechanical and not the best. I have not touched the PCM and I have driven the car about 50miles with no Problems or CEL.

Pulley Technologies say this is a 15% pulley they also sell a 10% pulley(3.00inch) go to ebay for the details.
 

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I have the same parts on my car. I am going on close to a week now with no ecu problems at all.
 

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This is good info, thankyou!
12.5 is jyst about dead on perfect. Nice and safe.
It would then seem that the computer reads the airflow and adjusts accordingly. One of the benefits of a mass airflow system.
Since no one else has posted such meaningfull results, I for one applaud your efforts!
I just bet that a lower restriction exhaust/muffler would also be a benefit.
Not sure about a header......the distance to the cat is so short.
Because you get boost quicker (expected), I'm interested to know what this does to the gas mileage? Do keep track of that and report.
Although I don't constantly watch the boost gauge, I have noticed that even relatively easy driving get's into boost pretty easy. Still getting 26+ Mpg.....but then I just passed 500 miles and I've been being nice to the engine.
Ron
 

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One more thing, don't bash the stock boost gauge until you know for sure it's not accurate. Auto Meter makes fine instrumentation.
A real mech boost gauge is only as accurate as it's calibration.......and unless you spend a bunch of $$$ for one, there is ZERO guarantee it is any better than the unit in the car. Want a perfect one? Find one that has been calibrated to National Bureau of Standards (NBS) and bring your checkbook. And get it calibrated every year for even more $$$$. I work with this stuff all the time.
Ron
 

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498Nova said:
One more thing, don't bash the stock boost gauge until you know for sure it's not accurate. Auto Meter makes fine instrumentation.
A real mech boost gauge is only as accurate as it's calibration.......and unless you spend a bunch of $$$ for one, there is ZERO guarantee it is any better than the unit in the car. Want a perfect one? Find one that has been calibrated to National Bureau of Standards (NBS) and bring your checkbook. And get it calibrated every year for even more $$$$. I work with this stuff all the time.
Ron

I don't think the stock boost guage was being bashed. The confusion stems from the Psi Fi piggyback and how it tells the ECM what it wants to see and that includes boost. An electronic boost guage will only show what the computer sees unlike a mechanical guage.

Nice job on the pulley dyno. That kind of info is extremely helpful.
 

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dazednconfused75 said:
I don't think the stock boost guage was being bashed. The confusion stems from the Psi Fi piggyback and how it tells the ECM what it wants to see and that includes boost. An electronic boost guage will only show what the computer sees unlike a mechanical guage.

Nice job on the pulley dyno. That kind of info is extremely helpful.

Exactly !!

there is soo much confusion surrounding mods and gauges... I have read several times that a piggyback is needed because the PCM limits boost ...
 

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Just curious

evilcobaltSS said:
My car use to run at around 10-11 maybe tap 12 for a second before redline but really about 10-11 after some buildup time. AF ratio across the pull was in the 12.5 range and never went above 12.9 even at above 6,300RPMS. The AF was mostly in the 12.5 across the board. I am not sure if this is to lean for these motors but I am glad it is not running in the 14's or someshit. The car is stock except for this mod.
Thanks for publishing that info. I'm looking forward to seeing the dyno sheet. Did you use the same air fuel sensor for before and after?

Pierre
 

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patathSS said:
Did you have to do any grinding or other modification to make room for the bigger tensioner?
No mods are needed to fit it on.
 

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to find proper air/fuel you would need a hand held scanner and some old school viewing...check and see if you are getting knock with that pulley and boost if you are not then pull the plugs fresh after a pull and check the color of the plugs they should be a little black meaning running a bit on the rich side and safe...

so it really depends on the car and motor and ecm...

i have a blowen 2.2eco i am working now that is running 15psi at 6000ft thats 19psi at sea level i will start tuning at 10:1 air to fuel till i get detonation or knock and then back up the air/fuel to last setting :D and then take it to the track and see what she does!

lol but air/fuel can be tricky sometimes as weather changes and octane rating it all depends!
 

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Pierre said:
An air fuel ratio of 12.5 : 1 might be lean for a supercharged engine on pump gasoline?

Pierre
i'm pretty sure the "light show" he was talking about was a reference to the light tree when running the quarter... as in "let us know what it does in the quarter"
 

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My bad...

iso said:
i'm pretty sure the "light show" he was talking about was a reference to the light tree when running the quarter... as in "let us know what it does in the quarter"
That makes more sense ISO. Probably a little generation gap on my part.

Pierre
 
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