Well i put the 2.5" on from going from a 2.6" and i honestly can't say it feels any different, the car was holding a constant 11.6 at redline on the uego gauge and now its creeping up to 12.6 with the meth. Now im guess now i need a retune or should i just put the 2.6" on it cause i do have some charger work inside.
And for those of you that wonder, i saw 7psi on the 2.6" and i see the same with this....
Edited 1 time(s). Last edited Saturday, April 19, 2008 1:39 AM
wow if your seeing the same then why is your air/fuel going from 11.6 to 12.6 . must b some change!
Is the charger ported or your head?
BOOSTED BABY wrote:wow if your seeing the same then why is your air/fuel going from 11.6 to 12.6 . must b some change!
My thoughts exactly. I wish everyone would get off this whole boost number thing. It does not mean squat all that really matters is whp!
FORGET GIRLS GONE WILD WE HAVE GOVERNMENT SPENDING GONE WILD!
jesterz413 wrote:his profile says he does have head work
LOL His profile leaves me with more questions than answers such as
What are SI valves? Are they oversized? I bought my valves from car customs. They are stock size stainless steel vavles.
OK so you have some special JBP lifters and 2.3 springs but no mention of what cams you are using. LOL
You mention a milled head and valve job but no mention of if it was ported or polished.
FORGET GIRLS GONE WILD WE HAVE GOVERNMENT SPENDING GONE WILD!
Well you won't see much of a gain in the psi department if the head is ported it will naturally drop the pressure but in turn lwill increase horsepower. With positive displacement pumps psi is a relative number because it increases with obstructions in the airflow but this will put more stress on the engine and charger. Where as with a cleaner flow path you will see less boost but make about the same power if you were running more psi effciently. And with the M45 effciency is what you want.
I always thought that the 2.5" overspun the M45 and was a waste, just from info I seen a long time ago.
I've been out of it for a while though, so I could definately be wrong.
over *spinning* just means its out of the efficiency range, the heat takes down the power it would make, solved by methanol injection
at least that's as much as i know about overrevving the charger
2001 Olds Alero (LD9)
650 whp / 543 ft-lb
@turboalero
How is my profile leaving more questions than answers? SI valves are the valves karo sells at car customs if you did some research. Karo himself told me they are SI brand valves. I'm simply running the w41 JBP cam clones, nothing special. I still am puzzled as to why my AFR is leaning out now after the pulley change but the power doesn't seem any different without going to a dyno.
because you're leaning out, of course.
hit the track/dyno and get some answers, the butt dyno and a boost gauge isn't going to tell you much
2001 Olds Alero (LD9)
650 whp / 543 ft-lb
@turboalero
if you are still running the GM tune this is the most pointless thing ever.. i have had a few GM supercharged 2.4L's now and i can honestly say 2.7" is the smallest i would EVER go with out getting it re tuned... and at 2.6" pulley you must be running alky (i see you are though) but to get any kind of gains you must have your car re tuned, the GM tune is @!#$ at best with the stock 2.8" pulley. To prove a point i left the 2.8" pulley on my sisters cavy and just did a HP tuners tune on it and gained i believe it was 8whp just from a quick clean up...
but like is has been said above, a 2.6" pulley is spinning your s/c'er at approx 16,500 rpm (if i remember correctly) which is getting past what eaton says to spin it. They dont say this because the bearings cant take it, they say this because your spinning past its efficiency range and it is producing to much heat
The First Twin Charged jbody
blue car (R.I.P) - 240whp @7psi..
silver car - 305whp 315lbs.tq @15psi (91 Octane) or 420whp & 425lbs.TQ @20psi (94 octane+Alcohol Injection)
All dynos run on a Mustang dyno
im not on the gm tune, i have a base tune for the 2.6" pulley right now, its made to run that pulley with a 50 shot but im not running nitrous so i have alot of timing to advance and such
Are you running stock compression ratio?
Ok I can tell you right now even with meth injection your blower is out of its effciency range. SO you might not be seeing any gain if you do its slight your blowing alot of hot air and even though it is getting chilled its still pretty hot. What do your IATs look like?
If you want to make some more power your going to have to bump that compression ratio to about 10.5:1 you will make mor poweer with less effort. It will be a pain to tune but well worth it in the end. I've seen these little M45s produce a 100 horsepower increase with a compression bump.
