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I'll get more in the specifics soon....
Well, add more to the Alpine/SC crap pile!
Found out I'm running a 4psi pulley, supposed to have a 5psi pulley!
....keeps get'n deeper folks, I'm calling Alpine, stay tuned....
This is where I got it done www.dynocomp.com
what are the diameters of your pulleys? I will have to measure mine to see if the same. I also need to hook up my boost gauge and just measure the boost.
That's the tricky part, it's supposed to be 52mm for a 5psi....53mm for a 4psi.
A tape measure won't cut it and Alpine told me to measure from the threads, so I would have to pull off the belt?.....come'on, I can't do that....no tools.
http://www.vehicross.info/gallery/data/500/901boost.jpg
Hp and torque dyno chart
http://www.vehicross.info/gallery/data/500/901hp.jpg
Here is Anita Dyno'd with just the catback...
Humm wonder what is up?
http://www.pvmufflers.com/0ac547b0.gif
Something doesn't look right. I certainly hope all of us with superchargers didn't invest $4,000+ to dyno out at 185 HP compared to a VX with just a cat back system (Anita's) that dyno'd at 188.7 HP. I'm no dyno expert, but either the dyno report on Anita's VX is not correct or the one you just had done is not right.
To help better understand, this is a 4WD dyno, not rear wheel.
http://www.dynocomp.com/images/tuner/dyno_tuner2.jpg
....... no surprise ......
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of course Anita(s) is hot !
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two different dynos ....... runs on different days ....... etc etc ...
Alpine is certain that there is a 5psi pulley on my kit. Now, is there any mistaking that there is 5psi pulley on there?
I repetely asked the Dynocomp guys if there was any way that why it's not running at 5psi...."sure, your running a 4psi pully.".....are you positive? "positive".
Alpine can't believe that.
So, I think I have to pull off the belt and get it measured by my shop on top of my cone being either replaced or resealed(witch they still have no answer for me on that).
Is it me, am I nuts? Or is this a huge pain in the ***?
Sound to me like it a pain in the arse. Sorry your having so much trouble with your SC, mine has been trouble free.
I hope that the shop can fix/seal the problem or that Alpine will pony up. I felt a nice difference when I switched to 5 lb pulley, hope it was not all in my head, as my boost gauge reads 5 psi when I am in boost.
How is the truck running? Have you gotten on it? Does it feel faster to you?
Good Luck.
-Dave
one thing you need to know about dynos. they use a correction factor (for temp. humidity. etc) . you can make it say whatever you want. by using a different correction factor. shawn
Holy bageebiz, Alpine called me back!
They are sending me a new nose cone assembly with a new pulley, oil, sealent and a fuel line.
I asked them to please double check on the size of the pulley before they send it out. Thing is, I have to pay to install it....again.
autox-racer- put in your gauge and see what your push'n and if you got the time measure your pulley and see if it's 52mm or 2.05 inches from the "ribs" of the pulley. I'm curious to see what you come up with.
Cyrk- I do notice a big difference in performance(a lot more when it's cooler), but if I have the wrong pulley, that 15-20 extra horses would make a biger difference. Did you have the guage with the 4psi pulley and did the guage show it at 4psi?
Tell us how your shop (hope they are better than the installers who told you rich would blow the motor) determined you are at 4 psi? Gauge? Where did they tap it? Depending on where, you will get different readings.
And are you running rich or lean? What is your fuel pressure? What plugs are you running? What correction facgtor did they use?
Measuring is simple and ouside diameter of the overall pulley will only get you in the ballpark - measure where the belt rides with calipers - yes it is BIG hassle to loosen the belt. . If ya'll can't tell a difference with the SC installed there is a problem with the NBTW. And if you didn't dyno before you installed and then again right after, you have NO room to whine. When a blown VX walks a stock one at the track or on the street, what would you say accounts for that? It ain't gonna be LESS HP!
And BTW, in 2WD, a min of 20% power is lost in the driveline to the rear wheels - in 4WD there is even more loss. A before and after would have shown the overall increase after making a single change. I ask John to call you so you'd chill - guess it didn't help.
From where I saw them test the boost they put a line what looked like behind the SC, it was detremind by the computer(see chart above) that's what they showed me to say I was running at 4psi.
My fuel/air was perfect(see chart above) and that was my main concern, they reassurded me I was running fine.
Plugs- stock and if you have a suggestion on replacements, I'm on it.
correction factor- don't know.
They told me there is close to a 40% loss in power in the 4wd drivetrain and the TOD did'nt help. What they were most impressed was the tourqe and one of the guys there compared it to his Trooper 3.2L and he was impressed with the overall performance and wants a SC for it.
I'm not complaining about any of the performance, it's got bigger balls now. I just want it running at peak and seeing it at 4psi pissed me off....there's 15-20hp that's supposed to be there at 5psi.....if that's the case.
When I get my new cone and pulley I'm going to measure the two pulleys and see, at that point we will really know and I'll dyno it again.
I am chill, I've spoken with John(Alpine) and told him my concerns polightly....but I don't like being left in the dark....that's what really pisses me off. Thankfully, I have you guys here to buffer that and I'm learning a lot and I hope you guys will learn from this as well. I'm giving blow by blow comintary of everything I'm going though hoping that if anyone runs into these same problems you'll be a bit more prepared than I was.
;)
http://www.pvmufflers.com/0ac547b0.gif
I'm a little weirded out by this dyno chart, is the rpm supposed to decrease after 3500rpm then slowly rise?
Watching the dynocomp guys, it was a steady rise on acceleration threw each run(4-5 runs)...are there different ways of running a dyno test?
The RPM is a steady rise, but the HP generated by Anita's VX (all VXes?) does seem to start climbing again after 4000 RPM. What we are most concerned with (and why I own a PV cat-back exhaust) is the max HP. 20HP increase over stock at @ 3500 RPM... yee ha!Quote:
Originally posted by jayfotos
I'm a little weirded out by this dyno chart, is the rpm supposed to decrease after 3500rpm then slowly rise?
Watching the dynocomp guys, it was a steady rise on acceleration threw each run(4-5 runs)...are there different ways of running a dyno test?
http://www.alpine-developments.co.za...2L%20dyno.jpeg
Looking at the dyno chart from Alpine's site (I hope they don't mind me borrowing it), the HP gain after adding a supercharger would just about double that of the PV mod. Plus, it looks like the max HP comes at higher RPM.
Man! I've got to start saving my pennies! :goof:
wow 200hp 200 lbs to teh floor.
is this on a 4w dyno?
________
Striperella live
I'm having a little trouble figuring out these graphs. Maybe someone more knowledgable can help explain a few things. First of all, how is it possible that torque decreases while hp is increasing (after 4000 rpm's)? Apparently there is not much difference in either one between a SCed and nonSCed vehicle at 3000 rpm's? What does Jay's first graph measure?
Finally, Jay, why was it necessary to get dynoed in order to determine if you had the correct air/fuel mixture? Did they install an extra O2 sensor in your exhaust or just use the built in one? (Hopefully they plugged any holes.) Just wondering; but any answers would be appreciated. Thanks.
I'm new to the whole dyno thing and my main concern was testing the feul/air....because I was told by my shop to run a feul regulator on any turbo or SC....I tested fine.
What I recently found out was my stock air box can't take the suction(without any modification) of a 5psi....and I think this is the problem, see this post.
http://www.vehicross.info/forums/sho...&threadid=4573
I plan on installing a cold air intake that should take care of any power loss....at that point I'll dyno it again and I'm sure I should see a meager improvement.
Oh, the first graph measures psi..as you can see 4psi straight across....and I have a 5psi pulley(not certain on that still have to install the new cone, at that point I'm having everything measured)....the other is the air/fuel, witch is steady.
Thanks Jay. I found my own answer to the question of the difference between torque and hp. If anyone else is interested here is a link.
Though, I still don't see why you needed the dyno to measure air/fuel. Couldn't you just install an air/fuel gauge and then drive around? I was curious about AWD dyno testing myself until I found out the price. Decided I wasn't that curious. Hope it didn't set you back too much.
I did 4 or 5 runs and it cost $140. Along with seeing how my air/fuel I wanted to see if they noticed anything wrong while running it, all was good(except boost)
Jay
I too had my VX tested at Dyno-Comp, several times last year. I can't seem to find my printouts, but as I recall I maxed out at 196 HP. This was with a 4 lb. pulley and a two filter after-market intake. A second test session yeilded 184 HP. This time I was running 4 lb., a Cal-Mini cone filter and it was considerably hotter outside, which probably retarded the timing a bit.
The August 2004 Sport Compact Car magazine has a test of 4 wheel dynos. Some very interesting information comes to light in their article.
First and foremost, no two dynos measured the same horsepower. Not even two of the same manufacturer. Secondly, the difference between 2 and 4 wheel horsepower ratings were anywhere from 5 to 30% different. In all cases the 4 wheel numbers were lower.
The most telling info, in regards to this thread, is that the Dyno Dynamics dyno had the very lowest horsepower numbers in both 2 and 4 wheel drive. The worst case was a deficit of 54 horsepower when compared to a Dynojet in 4 wheel mode. The dyno at Dyno-Comp is a Dyno Dynamics unit.
Another interesting fact was that the Dyno Dynamics dyno produced the most consistent numbers from run to run, which would seem to indicate that it was actually the most accurate at measuring.
The Dynapack dyno, which I believe was the unit the PV muffler and Alpine charts were generated on, measured almost identically to the Dynojet units. This would translate into about a 50 HP gain over the numbers generated by the Dyno Dynamics machines.
Moral of the story... Dynos are really only useful if you get a "before and after" measurement. If you want bragging rights, go find a Dynojet dyno to produce the highest numbers.
Yeh, I don't take dynos to seriously......only when they tell me I'm not running at the boost I was supposed to and I think thats something you can mess up on a dyno(getting a boost reading)
J