My dyno was done on a Mustang dyno ...so it would come out 11 to 12 % lower than on a Dynojet dyno . Mine came out 338whp and if you add 11% it came out to be 379whp and 312 trq. Mustang dynoes [if set up right] put more load on the motor and make it work harder , so thats why they come out lower

 

myself and others are higher than 360 with the 8lb pulley, you should be close to 400 with the 9lb pulley, im thinking about getting this pulley but i need to know which one it is, is it known as just the "9lb pulley"? i wonder if i can get it from superchargers online.

get colder plugs, retard the timing, watch the rev limiter, just be careful and you should be fine, i say watch the rev limiter, but i never do, i bounce of the thing like crazy, i havent heard a ping yet.

 

tig488

I suspect in reality you could use a number of 9lb pullys and see the same result. However, in order to ensure you don't void your warrenty it might be prudent to use the Vortech version. Grubbs is putting mine in for $100 more than the cost of the standard pully. Also, I was told by another forum member that he got his for $125. I don't think these prices include install

 

You should ask the dealer what type of Dyno was used to get your HP numbers . They may have use a Mustang Dyno.....if they did...your making real good whp

 

yeah id use the vortech one, i just need to know which one it is, superchargersonline has them for 70$ but i need to know how many ribs it is and what diameter it is.

 

This thread should be moved into the FI forum, IMO.

Anyway, I believe I was the first one to install the 9lb pulley (about a month ago). Or at least none of the guys I talked to when I called Vortech had any experience with this. After some back-and-forth discussion, their engineers concluded that the 34-tooth pulley from the Corvette kit might just barely fit in the location of the 32-tooth pulley on the 350z/G35 kit and would only require a slightly longer bolt. Total cost from Vortech was about $60.00.

I had to loosen the mounting bracket to be able to remove the old pulley, so it took about an hour to do the swap the first time. It appeared to fit, but after a couple of days, I noticed that the bolt on the back of the 9lb pulley touched the intake tube at WOT. Watch this very carefully because the bolt spins and will eat a hole in the tube. I was able to remedy this by using a thinner washer and I no longer get rubbing. This problem might be unique to me since I had the 350Z kit custom installed on my G35 sedan. There might be more room on a G35 coupe and/or the Z.

With the auxiliary pump, having enough fuel is not a problem but I personally did not get much of a top-end gain with the 9lb pulley. Certainly not a 12% HP gain. More like a 15-20HP gain from 4000rpms to 6000 rpms. Obviously, the difference is that the new pulley makes more boost earlier, so there's more area under the curve. I'm not sure why I didn't see a more drastically higher top HP number--but I have several hypotheses. One of which is that on really hot, humid days even SAE correction cannot account for the loss of power to a supercharged/intercooled system (especially with the air-restrictive G35 bumper) and on the day I did the tuning it was freaking hot and humid. I'm still experimenting and may try Aquamist or similar. I'll also redyno when my new bumper cover arrives

I did retuning with the R4 software, and the good news is that the 9lb pulley causes the SS box to utilize different cells on the A/F map than the 8lb pulley (everything is just moved one or two cells over to the right), so you don't have to have two different maps. You can tune a single map to work for both pulleys (although the cells "touched" by the 9lb pulley might have slightly different values values than those "touched" by the 8lb pulley).

Lastly, I just barely had the Technosquare L-Spec reprogram done on my ECU while I was on vacation last week and got the ECU put back in this morning. I haven't had a chance to measure boost at 7000rpms, but I'm guessing it will be in the 10psi range.

With a rev limit of 7100rpms, I don't know if I'll leave the 9lb pulley on or not. For now, I have one step colder plugs, I'm taking out 7 degress of timing above 6500 rpms, I'm using 100 octane fuel around town, and I'm going WOT with caution. I'll keep everyone posted.

--Steve

 

well why dont you just take that 9lb pulley off and ship it this way, ill take it off your hands for you.

15-20 hp(if thats a good estimate) especially at earlier RPMS, seems like a good gain for 60$, question is how safe is it, im assuming thats why you are being cautious, im gonna wait till you get a little more comfortable zimbo before i proceed with this

 

I used the 9lb pulley fearlessly until this morning when I put in the reprogrammed ECU. As long as you're retarding timing, watching A/F, and getting enough air to the intercooler I wouldn't worry about 9psi at 6500 rpms. It's the 10psi at 7000rpms I'm more worried about.

--Steve

 

Any comments on gas mileage with this pulley? (I'm talking in general...not floor stomping continual bat outa hell driving).

I'm just curious in general how the fuel consumption rates when you start getting into the higher boost levels....especially compared to a TT setup from Greddy. About the only thing hold me back from an SC...

 

im just worried about the levels of hp were getting into here, at what boost is the internals safe, if im getting close to 450 at the crank with the 8lb pulley, and youre getting another 10-15%, maybe, what do you think the internals are going thru. i bet they are reaching their stress levels.

 

Valid concerns. I'm probably only at 375rwhp on the top end even with the 9lb pulley so I'm not sure how dangerous my current setup is compared to, say, mcduck with his 425 rwhp.

Here's my current plan... I'm going to get a bumper similar to your TS bumper (but for the sedan of course) so I get better airflow and I'm going to go with an Aquamist or similar water/methanol injection system. I'm going to see what that does as far as keeping the system cool and safe.

However, ultimately, I'll probably rip the supercharger out of the car and go with a TT kit at 8psi.

What I don't know is how stressful a 9lb supercharger pulley is compared to an 8psi TT kit. My uneducated guess is that a turbo system is actually more stressful because the duration of the boost is so much longer. But what do I know?!

--Steve

 

moved

 

Is that 100RON or average of RON & MON?

 

I have no idea. It's right next to the pumps that sell 87, 91, and 93 octane. And 100 octane costs about $4.30 per gallon in case you're wondering...

--Steve

 

Sorry, there is really no other feasible way to listen for pinging. EGT and A/F wont tell you for certain....nothing will...except for the sound of pinging (think BB's in a coffee-can). Our ECU has a knock sensor, which is nothing more than a microphone mounted to the block, that detects detonation.....the pinging is a very specific frequency...so the ECU's sensor listens in this range only. If it detects knock, it will attempt to retard timing on the next compression cycle of all the cyclinders. The problem is that it can only retard timing about 4 degrees, and only after significant audible detonation has occured. Essentially, the sensor is a bit slow to react, and it's lazy...only retards 4 degrees or so.

You just need to drive the car with windows down..radio off...on a street, that hopefully has a wall on one side of it...get in the right lane. Punch it an listen...if you hear anythig other than the sweet sounds of F/I, your engine singing, and the sweet exhuast note....STOP! The sound is characteristic...you cant miss it.

Oh, and for tuning purposes, dont worry if you hear a bit of pinging....it wont kill your motor instantly....just let of the throttle..make your adjustments..and try again. You never wanna continue at WOT if you hear pinging.

By the way, I think some parts stores sell a device that is literally an "in-engine microphone"...no joke. You mount it the block, and run the wire back to a set of headphones and some other filtering device, and you can literally listen to everything going on inside the engine..you can hear injector PW, valvetrain sounds...knocking...everything.

 

Houston G35...
Enron Exec posted this, but don't expect to hit those numbers. I'm turning 425 rwhp with the Vortech on my 350Z. I've been told I'm turning between 9-9.5 pounds of boost with the stock pulley when I hit this number. Also, I have cams, headers, cats, exhaust, plenum, etc. Without those extra mods, but using the 9lb pulley, I think 380-390 is more realistic.

That said, I've been running 400-425rwhp (figuring a little variance for when the belt gets a little loose and has to be retentioned). That should be somewhere in the neighborhood of 500 crank hp. My car's been this way for almost 2 months with no issues other than a minor belt problem not related to the install. I am running one step colder plugs, but I agree with gq_626, with the new pulley, I'd move to two steps colder.

Also, to date no transmission or rear end problems (knock on wood). With stock wheels, you will have serious traction issues!!! I'm running 275/40/18 Bridgestone S-03s on the rear now. With 425rwhp, if I want, I can spin the tire completely up to and half way through 5th gear. And it's easy to get a nice squawk of the tires dropping to 3rd gear at highway speed. If I were you, I'd make upgraded wheels and rubber your next project.

zimbo
Talk to me... You say you put on the 9lb pulley, but didn't see any big gains at peak. This is good news to me. What I would prefer are gains where the HP is lower. What's the increase look like in the 2500-4500 range? If it only adds 10-15 at peak, that will still keep me below 450, but may give me enough low gains to make it worth the change. Also, how much R4 reprogramming did you have to do? (and would you be willing to share those adjustments with me so I could make the same updates?)

 

Andy, your car sounds like a beast. I'm still extremely curious as to why your Vortech seems to show more boost right out of the box. Maybe the unorthodox pulleys?

Anyway, if you watch the fuel map while your car is running, you'll see that as boost follows RPMs, the current active cell will follow a diagonal path from top left to bottom right, roughly similar to the path of the Xs in the diagram below (the X-axis represents boost and the Y-axis represents RPMs):

XX0000000
0XX000000
00XX00000
000XX0000
0000XX000
00000XX00

In my case, adding the 9lb pulley had the effect of simply moving the Xs over to the right by one or two cells, like so:

0XX000000
00XX00000
0000XX000
00000XX00
000000XX0
00000000X

In other words, at a given RPM the boost is slightly higher. This means that you only need to modify the cell values that are actually "touched" by the 9lb pulley (perhaps increasing the number in each of those cells by one or two tenths of a point). I'm assuming that if Underground racing did your tuning, the fuel numbers for a given row are all the same--which isn't really the ideal way to tune the car for the flattest A/F graph but it would make it easy to see where you've made changes if you increase the 9lb cells by a tenth or two. It's hard to explain in writing and I'm sorry I don't have screen shots to make this more clear.

Another thing to consider doing instead of the 9lb pulley would be to increase your rev limit. This has essentially the same affect as increasing the boost with the added benefit of potentially reducing the number of total shifts during a run. For example, if you're doing a 1/4 mile run with a rev limit of 7100 and you shift right at redline then you would essentially stay 500 rpms higher throughout the entire run (and hence your boost level would be that much higher the whole time as well). I'd have to do the math, but I'm pretty sure that the net "area under the HP curve" affect of staying 500 rpms higher during the entire run would be greater than the net affect of the 9lb pulley--at least based on the gains I have seen with the 34-tooth pulley.

--Steve

 

Steve,

Thanks for the info. I think I understand what you're saying and, if I'm reading correctly, I will have to make some minor adjustments to a select range of cells across the board. So, only fuel map changes... no timing changes between the 8lb and 9lb pulleys?

I agree having a higher rev limit would produce the same peak effect, but what I'm looking for is more mid-range power. Essentially, I want to hit my current numbers earlier in my powerband. So, raising the rev limit would not meet my requirements. It would raise my absolute numbers (probably higher) than the new pulley, but it would not really change my low to mid-range numbers where I'm seeking improvement.

As for my higher boost numbers... the only things I can figure are either UR pulleys (though I have stock crank pulley) or the Crawford Plenum. The first may be affected amount of boost produced. The latter may allow more volume of air to be moved, thereby allowing more air to be "pushed" through the system. Regardless, I only have what others told me to go upon. I really need to get the R4 hooked up and take a snap shot of what's going on to see first hand.

An unrelated question... does the split second retain its settings with the battery disconnected? I presume it does, but want to be absolutely sure before leaving the battery disconnected for a prolonged period of time (24 - 36 hours)

 

I have the Crawford plenum so that isn't what's giving you the extra boost--it certainly helps your overall HP number though.

Yes, the SS box retains its program. I left my car disconnected for one week and it wasn't lost.

--Steve

 

Hey all....
I just want to pipe in here and say there is no "authorized" pulley change for the Z. We keep tabs on the pulleys by putting "paint" on the pulley that is attached to the blower, if this is missing or tampered with, no warranty. With this new jackshaft setup that we have for the Corvettes and 350Z/G35, you can change the size of the jackshaft pulley to get the same result without messing with the paint. This is how to get around the 3-year warranty scare. However, there are ways to tell if a supercharger has been overspun. In additon, please be warned that messing with pulleys could damage your motor and adding more boost without changing the SS box tune could also damage the motor. I am not looking to burst any bubbles, but I don't like to see someone saying "authorized" when it is not.

On a side note, I think it is great that we have so many people on here now familiar with the product and how to tune the SS box. Thanks for all the support and keep up the good work!