PDA

View Full Version : Superchager question



V12BMW
08/23/2005, 01:07 AM
all you out there that have superchagers what kind of hp are you getting now? a stock vx is 215hp right? whats it up to now?

Ldub
08/23/2005, 05:03 AM
Here is Jayfotos dyno chart: (s/c,carbon fiber intake, cone filter)http://www.vehicross.info/gallery/data/500/thumbs/901hp21.jpg (http://www.vehicross.info/gallery/data/500/901hp21.jpg)
This indicates HP at the wheels...as I remember, the first run was s/c with stock airbox, the second(higher curve) was with c/f intake & cone filter.
Jay, jump in & correct me if I'm wrong on this.

Ldub

Cyrk
08/23/2005, 09:27 AM
We had our VX dyno'd back in March on a Dynojet 4 wheel Dyno here were the results... I have since added a 10:1 Fuel management Unit to the mix and will be getting it re dyno'd hopefully next week to see if it is running any richer and if the boost curve as smoothed out any.

and the thread: http://www.vehicross.info/forums/showthread.php?t=6423&highlight=dyno

johnnyapollo has a 01 Proton with:
- Powervault generation 1 catback exhaust
- HotShots Air Intake
- Trans Interceptor Shift Kit
Not sure if they plays at all into it, He is running stock 18x7in rims w/ 255/55/18 Scorpions
His best of 3 runs was: 153.04 Max Total Power & 174.13 Max Total Torque

I (Cyrk) have 99 Ebony with:
- Alpine racing developments supercharger
- 5psi pulley
- Modified HotShots Air Intake to fit SC
- Powervault generation 1 catback exhaust
- Denso Iridium IK20 (one step cooler) spark plugs
- Trans Interceptor Shift Kit
I have Aftermarket 18x8in rims w/ 255/55/18 Toyos
Best out my 3 runs was: 216.21 Max Total Power & 227.65 Max Total Torque

Looks like A SC VX in our case made 63.17 more HP and 53.52 more TQ over a slightly modified one, too bad we did not have stock one there also... bet it would be close to 75HP more than stock.

Interesting on my 3 run I have a TOD disconnect switch and we ran with that on, well it looks like the front drive shaft is still connected, it ran the slowest of my runs at 193.61 HP and 204.38 TQ.

The Air/Fuel on my SC VX was running a little lean as John's was just a bit rich... I am going to look into a adjustable fuel press regulator and try to drop into the rich area and squeeze a bit more HP out of her. Also I want to get Tone's intake with the green filter for our SC... and dyno again with that mod.

Here is the Dyno graph with mine and John's run overlaping... and some other pics. I got some video of the runs but they are too large to post.
http://www.vehicross.info/gallery/data/500/thumbs/39Dyno1.jpg
(http://www.vehicross.info/gallery/data/500/39Dyno1.jpg)http://www.vehicross.info/gallery/data/500/thumbs/39VX_Dyno13.jpg (http://www.vehicross.info/gallery/data/500/39VX_Dyno13.jpg)http://www.vehicross.info/gallery/data/500/thumbs/39VX_Dyno8.jpg (http://www.vehicross.info/gallery/data/500/39VX_Dyno8.jpg)http://www.vehicross.info/gallery/data/500/thumbs/39VX_Dyno7.jpg (http://www.vehicross.info/gallery/data/500/39VX_Dyno7.jpg)http://www.vehicross.info/gallery/data/500/thumbs/39VX_Dyno6.jpg (http://www.vehicross.info/gallery/data/500/39VX_Dyno6.jpg)http://www.vehicross.info/gallery/data/500/thumbs/39VX_Dyno5.jpg (http://www.vehicross.info/gallery/data/500/39VX_Dyno5.jpg)http://www.vehicross.info/gallery/data/515/thumbs/39VX_Dyno1.jpg (http://www.vehicross.info/gallery/data/515/39VX_Dyno1.jpg)http://www.vehicross.info/gallery/data/500/thumbs/39VX_Dyno2.jpg (http://www.vehicross.info/gallery/data/500/39VX_Dyno2.jpg)http://www.vehicross.info/gallery/data/500/thumbs/39VX_Dyno3.jpg (http://www.vehicross.info/gallery/data/500/39VX_Dyno3.jpg)http://www.vehicross.info/gallery/data/500/thumbs/39VX_Dyno4.jpg (http://www.vehicross.info/gallery/data/500/39VX_Dyno4.jpg)

AlaskaVX
08/23/2005, 10:16 AM
My butt dyno says +60 horses, and a 15.2 quarter mile time.

mbeach
08/23/2005, 05:58 PM
A 50% gain makes for a very respectable bolt-on. I wonder what that conservative 5psi would make with some intercooling (or water/meth injection).

<--begins to reconsider supercharger options.


Oh, making that A/F mixture richer won't give you any more power -it will actually steal a bit. The purpose of tuning rich is to cool your cylinder temps and give your engine an increased margin of safety when on boost. I wouldn't venture near the double digit boost levels without some serious real-time A/F ratio feedback on hand.

EDIT: Just took a closer look at your dyno chart, noticed some interesting stuff.
-that funny wiggle at 4300 rpm, I assume that it was a shift. Cyrk's came on a few RPM later -tire size/gearing differences?
-Both plots are almost exactly identical in form, even though Johnny still has his variable intake plumbing and Cyrk does not -can someone tell me what this doodad is for again?
-Both of you started slightly rich, even considering the presence of the CAIs (known to cause lean conditions in many boosted vehicles). I wouldn't be overly concerned with a 10-12:1 A/F ratio at this point. My 362whp WRX touched 9:1 on high boost (= mad flamage on Sunoco Blue :cool: ).
-Cyrk? (it's hard to tell on the graph) should be concerned with the flat-spotting of the A/F ratio beginning at 4400 rpm. It stuck you at 12.5:1 even though you continued to accelerate. Notice the lower curve's ability to increase fueling to protect the motor. I think your injectors are maxing out early -but I don't think that the adjustable FPR is the way to go (That's how Honda boys do it).
-I assume that the VX has its fuel rails in series (right, then left) consider converting them to a parallel feed system (this will ensure equal fueling to both banks, preventing a lean cylinder when you begin tuning on the edge). This isn't as hard as it sounds, and its a common safety mod.
-Has anyone benchtested their injectors? Often better flow can be obtained by opening up the spray pattern. Check what's downstream of the spray path, you still want the mist, but without wetting the walls of the intake manifold.

After you can safely enrich the A/F ratio, and ensure equal fueling to all cylinders, then it's cool to advance the timing (how?!?) and crank up the boost.
I'll be interested to know how far the Isuzu motor can go before it starts making bad noises -hopefully some of Isuzu's bulletproof diesel tech has made it into these engines as well.

MZ-N10
08/23/2005, 06:27 PM
at 4300 rpm is when our varible intake kicks in....i think

Ldub
08/23/2005, 06:42 PM
MZ,
There is no more variable intake after s/c install...if thats what you were refering to.
Ldub

MZ-N10
08/23/2005, 07:29 PM
MZ,
There is no more variable intake after s/c install...if thats what you were refering to.
Ldub

o didnt know tat

Ldub
08/23/2005, 09:07 PM
mbeach,
This is just my understanding of "variable intake" after having mine apart...take it for what it's worth.
There is a set of "butterflys" in the intake that, when open, lengthen the intake runners thus increasing the velocity of the charge going into the cylinder.
I kinda miss that little spike in the powerband since s/c install...but not all that much. ;)
Ldub

WormGod
08/24/2005, 07:34 AM
Now lets just start shaving down some weight on these things and get that 1/4 mile eta down to a wee better time. :D

I havent heard much from FeatherFoot lately on his research. That would be another major aid.

mbeach
08/24/2005, 09:40 AM
Oh, one more thing I just noticed.
Jay's VX is not likely down on power when compared to Cyrk's, even though Jay peaks at 20+ hp less on the graph.
Jay's run(s) were done on a Dyno Dynamics unit, and Cyrk's were run on a DynoJet.

The debate rages, but most professional tuners give the nod to the Dyno Dynamics dynamometer for accuracy. Dynojets have been known to be more optimistic.
I've noticed a 10% difference from dyno to dyno and from day to day with the same car.