Well, I went out searching about pullies for my S/C and the only two sites that show anything specific are Pulley Boys and Maxx Autoworks. Pulley Boys boasts a diameter of 2.1" at the smallest and Maxx Autoworks won't release the information. They will only ask if you are at sea level or not. This sounds like just what Gadget has described on his site. Has anyone purchased one of these from either store or does anyone have a better source?

Todd

Gadget, what do you think?

 

You are asking Gadget what he thinks about MAW?



Oh, this should be good!

 

Yeah I have read his write up on his site and after hearing the explanation of their pulley size he sounds dead on.

 

Go with pulley boys!

Chris

 

i have a 2.00 inch pulley that works ill sell ya if you want. 50 bucks!


Tim

 

How much boost dose the 2.1 ~ 2.2 pullies at pullyboys.com make

 

I don't know they don't claim what psi it will give. That is almost misleading because every rig is different. Maxx Autoworks seemed to be borderline rude when I asked why they would't release the diameter of the pulley. They way I see that is they have something to hide and according to Gadget they do! Anyhow just got an email back from Pulley Boys asking how small they will go on the pulley, they asked me how small I want it. I am going to start going to the track and plan on racing more so I might test out a 1.5" pulley for racing. Got the heads and am saving to send off to f2uning. Those guys are really nice and seem to be very reasonable in pricing, thanks for the advice Gadget. I will let you guys know what I find out.

Todd

 

Generally, I do not think it is a good idea to use a smaller pulley. That little TRD supercharger is already overworked as it is and spinning it faster is going to make more heat then power.

I have a MAW pulley. They sent it to me free to try out. It appears to be well made. It will give you more bottom end and a little more in the mid range, and it is hard to say, without dynoing it, but it seems to have no additional top end or maybe even a slight loss. I took it off.

I do plan on putting it back on for a short time to test discharge temp difference since I now have a compressor discharge temp gauge in one of my trucks. It would be good to know.

If you want I could measure the diameter of it and let you know what it is.

Now, if you really want to make power, you are not going to find it with more boost out of that little TRD supercharger. There is so much power that you can find with proper fuel delivery and tuning. Stay away from more boost and fuel it and tune it. Then you can have as much fun as me.

You can look right on the MAW site. They talk about and East Coast customer, me, and Jeff with the Taco. That is the truck they used on their dyno tests. That had their higher boost pulley, a fancy intake and a host of other things. They are making less power then me with a stock pulley, I am at 250 RWHP. The record currently as I know it is a 95 Taco stock pulley, stock exhaust manifolds, stock MAF, completely stock airbox with elbow in, cat back exhaust and my fuel mods tuned with a UNICHIP. He is getting 260 RWHP.

As you can see the true answer is not more hot boost, it is tuning.

If you want a nice performance upgrade kit for your supercharger for a great price, contact me in a couple of weeks. It is in the works.

Gadget

www.GadgetOnline.com

 

This is the email I just got back from Pulley Boys

Horsepower and PSI claims are what most vendors advertise, i.e.; a 5 lb pulley etc. But measurable boost is dependant on several factors including; temperature, humidity, altitude and engine flow characteristics etc, so any data offered by anyone is for reference only and should usually be taken with a grain of salt. Because of this and the fact that we make pulleys for
many applications, we list the actual pulley size as measured over the ribs and offer data where possible. The 1.5" pulley is custom work, price is $130 prepaid order. Prices for regular production keyed pulleys is $95. Shipping is $5 for US Priority
Mail.

Depending on how the current job goes, I may be able to turn one of these this weekend with anodize plate within two weeks or so


These guys are quick on their response and seem to be very professional.

Todd

 

Gadget - Be sure to keep us updated on the S/C upgrade kit. I am very interested....

 

I will stay tuned for your update, any idea on cost by chance so I know how much to set aside in the coming weeks? As always thanks for your insight and quick response, they are greatly appreciated.

Todd

 

Thought you guys might get something out of this.

This is Brian's email to me explaining the pulley size and boost ratio.

Do you know if going to a 1.5" pulley
> would be dangerous for my SC?

The bearings in your SC are rated 14K rpm, Magnuson (TRD supplier) has bench tested these blowers to 20K without bearing failure but they also state that this rpm is beyond the SC efficiency. I do not know your crank pulley size or pulley ratio is, it is certainly something you should consider. FYI, the MA pulley is 2.18" and produces 9.5 PSI. Our 2.2" pulley is also rated 9.5 PSI. Our 2.1" pulley produces 10-11 PSI, this is a very hot pulley
for your high compression engine. Many customers have trouble running the stock 2.37" pulley at 6 PSI so TRD offers a free 2.65" under-drive pulley rated 5 PSI.

A common question by customers from all vehicle applications is, "What do I need to do to run a x.xx size pulley?" This philosophy is exactly backwards, the pulley should be matched to the engine and modifications. Personally, I would try a 2.2 or 2.1 to see how it runs out for you.

> Would you put it on your supercharger?

I drive a '98 Pontiac GTP running 12-14 PSI @ WOT (stock was 7 PSI). Being a blown engine from the factory, it has a 7:1 compression ratio. I have done minor flow modifications (air intake and cat-back exhaust with slightly larger pipe to lower the torque curve) and use two heat range colder spark plugs. If I installed a cam and headers, I would need a smaller pulley to
maintain the same boost levels.

--
Brian Wicklund
Pulley Boys
www.pulleyboys.com

 

Todd i don't know if you are still looking for a pulley but elprototypes sells one.This is the one that i am running.It messures 2.0" and it is supoosed to be a 11psi pulley.I can tell you that on a hot day 80 to 90 degrees it will only push about 9 to 10 psi.On a cold day like today it is pushing12 to 13 psi.With the smaller pulley i do notice some pinging.Only if i stomp on it in a high gear and low rpms.I think if i were to just get rid of the o2 sencer surge it would run great.If i ease into it and let the o2 sence keep up it runs great.Which also leads to the fuel problem.I am running a bigger fuel pump with the boost-a-pump and a fmu, still stock injs.As far as the dyno i really didn't gain that much.
stock-7psi pulley/stock fuel pump/ stock fmu/stock exuast/187.2hp@5000 & 208.5fpt @4500
Then 11 psi pulley/bigger fuel pump/10:1 fmu/and i removed the cat/ 190.6hp @5000&210.7fpt@4500 Not that big of a differance.It doesn't seem worth it.It feels differant though.It does seem to pull harder down low and into the midrange.I also tried the ease into it theory were it seem that it is running great.Surprising it went to 195hp & 216fpt.Deffinantly fuel related so i'm saving for my URD fuel kit.

The tests were done on a mustang dynometer.From what i am told they read lower than a dynojet dyno, but i don't know if thats true or not. After i get my URD fuel kit and do some more testing i'll give you some more numbers.
-Elprototypes 626-812-0857 There web sight is down at this time under construction. Hope i could be of some help.

-Brian

 

A two inch pulley will over speed the supercharger.

The supercharger looses efficency dramatically when the boost pressure goes up. This heats the air. Hot air expands. Expanded hot air is much less dense. Less dense air means you are getting less air into the cylinder for making power. So, if you go up to high in boost, you are really getting less power making air into the engine and defeating the whole purpose.

I have seen the discharge temp on my supercharger hitting 220 on a hot day and it normally gets up to 200 and full boost. That is with a stock pulley. You are only going to make this much worse with a smaller pulley. The modified roots supercharger is nick named the back flow blower. As the boost goes up more air backs up into the supercharger and makes another pass around the rotors getting heated even more.

What you need to do is to cool off that charge air. The only practical way to do this with the TRD Supercharger is with water injection. I have been experimenting with water injection for a while now. I have tested it with a small nozzle and a stock pulley and have seen a 50-60* reduciton in charge air temp. I did not expect that at all, but I am a believer now.

I have tested it with a smaller pulley that is carefully sized as to provide slightly more performance without an overspeed problem. This combined with water injection is working very well. There is was a belt slipage problem, but I have licked that.

We are going to market the water injection system through Underdog and this pulley for those that want it. The water injection system will be ready very soon, and the pullies are being made now and should be ready before the end of January.

Wait till you see the super trick design of these pullies!!!!.

Gadget

www.URDUSA.com