Hey guys, was wondering what the typical boost range is for an 03 cobra with 2.76 pulley, exhaust and CAI? Currently getting it dialed in and I'm hitting 8lbs during 3rd gear WOT seems kind of low to me but not sure.
Boost range for Pullied Cobra
- Thread starter oscarigz
- Start date
2.76 Pulley questions
I had a chance to buy a billetflow 2.76 upper pulley for very cheap and was wondering how much boost that adds? Is it 6 pounds..I also have a stock blower and was wondering if that was to much to add to a stock eaton..thanks guys...Im kinda in a hurry I will be more specific when I get back..Thanks
www.svtperformance.com
What are you using to measure? I've had ref line to an aftermarket mechanical gauge get pinched and make me freak out before.
Last edited:
A 2.76" upper is not too much for the stock Eaton. You should see in the neighborhood of 14 lbs. boost. 8 lbs. is low, but then as @Black02GT asked, "what are you using to measure" boost?
Here's a link to some pulley/boost info from my Terminator FAQs.
CobraBob's Terminator FAQs - Pulley Boost Info
Here's a link to some pulley/boost info from my Terminator FAQs.
CobraBob's Terminator FAQs - Pulley Boost Info
I'm using an AEM UEGO failsafe wideband. On the dash it shows it around 11 lbs but not much higher. I'll have to recheck the vacuum for kinks.
I'm using the AEM failsafe wideband also on the dash it shows it around 10 to 11 lbs
Do you have a boost overlay and it’s calibrated or are you guesstimating past the 10lb mark.
And you said 8lbs in 3rd gear but also 11lbs. If you’re not spinning you should see roughly the same boost in every gear.
Which is it?
Sent from my iPhone using svtperformance.com
And you said 8lbs in 3rd gear but also 11lbs. If you’re not spinning you should see roughly the same boost in every gear.
Which is it?
Sent from my iPhone using svtperformance.com
This ^
It's reading 8 lbs on the wideband and 11 lbs on the actual cluster it has and overlay to 15 lbs
Are trying to remote tune or self tune. I only ask because you said "dialing in" and if it's at a shop, run.
My approach check all the pressured lines and more specifically all the rubber connectors to the nylon lines. Had the rubber connection split, (not fun when is the boost ref on the regulator on an aftermarket return systen effectively drops injector drop). Time but cheap if diy, make sure it is not a false reading. Then make sure fresh correct length belt. After that on to more time consuming and/or more expensive from there.
How are the A/F logs?
My approach check all the pressured lines and more specifically all the rubber connectors to the nylon lines. Had the rubber connection split, (not fun when is the boost ref on the regulator on an aftermarket return systen effectively drops injector drop). Time but cheap if diy, make sure it is not a false reading. Then make sure fresh correct length belt. After that on to more time consuming and/or more expensive from there.
How are the A/F logs?
Last edited:
I was getting it remote tuned with logs. I just looked at the wideband and noticed i was reading it wrong. Super noob mistake. It's reading right at 13 lbs both at the wideband and the cluster and then goes down to around 11 lbs past 5k. Afr is good throughout pull at 11.5. i can attach a video of a pull to show what I'm talking about
Last edited:
That's gotta be a pain to watch all that at once.
My 2.8" pulley made about 12psi on a stock blower. There really isn't any voodoo here. If you start at 11psi and end at 8psi you probably have belt slip. The main reasons a blower loses boost is either belt slip or a l leaking BPV. Check around the pulley for black dust.
My 2.8" pulley made about 12psi on a stock blower. There really isn't any voodoo here. If you start at 11psi and end at 8psi you probably have belt slip. The main reasons a blower loses boost is either belt slip or a l leaking BPV. Check around the pulley for black dust.
I think it's running good just hadn't paid attention to the numbers. Finally did a pull and recorded it to get accurate numbers and I'm at 13 lbs for most the pull. I'm assuming that's normal for my set up.
Yeah, actual boost numbers will vary with a specific upper pulley depending on, for example, your exhaust setup. A full exhaust with headers flows better and as such, causes a reduction of back pressure along with a reduction of blower boost. In that case, it's a positive change due to the motor operating more efficiently.
Thanks for all the help guys. Appreciate it!
Users who are viewing this thread
