Where's the boost?

[Supercharged98]

I have a Neuspeed supercharger on a 2.0L. Decided to buy a 2.6" pulley from PulleyBoys. It was supposed to add 2-3 more pounds of boost.
It was a stock 2.8" pulley, was putting 7#'s at 6000rpms.
3.5#'s at half throttle. Now I get 4-5#'s at half throttle and 5#'s at full throttle @ 6000 rpm's.

Any ideas? I'm clueless!!!!

All I did was loosen the belt tensioner, slid off the old pulley, then slid on the new one.

[peanutsmom]

If its a smaller diameter pulley, it will over drive the super charger and give you more boost. May need a stronger belt tensor to get the most out of the smaller pulley. (if it is a smaller pulley)Depending on the efficiency on the supercharger, over driving the compressor can up charge temperature and kill any power you would have gotten from the extra boost.

[connieray]

I have a Neuspeed S/C on my 2000. It has a 2.8 pulley and puts out 3.5 lbs boost. I asked Neuspeed about a smaller pulley and they said going to a 2.6 should bump it up to 5 lbs boost.

[Supercharged98]

I can't figure it out, I was already getting 7#'s with a stock pulley. I finally got my 7#'s back with the new pulley. The floor mat slid up under the gas pedal, not letting me get WOT, duh.

I gained 1.5#'s at half throttle, I just expected to gain the same at the top end. I wonder if it's set up to run no more than 7#'s? It has a sticker "Do not tamper with, pre-set at factory".

You should get between 5-7#'s at WOT @ 6000rpm's, with a stock pulley. You must be shifting too soon or not holding it to the floor.

[connieray]

I put the S/C on one year ago. I right away did not like the low end performance. It did not seem any different than before. But from around 4,000 to redline, it screamed and would hit redline really quick. I called Neuspeed to ask if they had moved the rev limiter up, and they said yes, it is now around 7,000.
With just the tiny little VW tach, I was worried about overreving it. The car has +140K on the original stock 2.0.
Just a couple of months ago, I did put and Autometer tach with shift light, and other guages, one being boost.
I called Neuspeed because I rembered reading something about 5 to 7 lbs boost. My boost guage only showed the 3.5. I e mailed Neuspeed and that is when they told me that the 2.8 only did around 3.5 and that going to a 2.6 would get it to around 5.
There was a problem with my tach and it is now at Autometer. As soon as I get it back, I will take it out, and get back to you with the results.

Here is the actual e mail from Neuspeed that I copied and pasted.

The pulley should be lazer marked, if you have a 2.8 the boost should be about 3.5 psi and with the 2.6 should be about 5 psi. The pulley is tight on the shaft, you will probably need a puller.

[connieray]

I do see the laser mark on my pulley and it is a 2.8.

One thing that bothers me is the throttle cable adjustment. When I first adjusted it, set the "bullet" looking end all the way back into the cable as possible. Had the wife get in and hold it to the floor, the bullet part came out and the throttle plates showed wide open. Drove it around a little and saw that the throttle cable had come out some more. I reset it and readjusted it again with the same results. Attached is a picture of where it is. I thought this may have something to do with the weak low end. Could you look at yours and see if they are the same? sorry for the lousy picture quality. Thanks

[Supercharged98]

My original pulley is marked only by "NEUSPEED". But, it does measure across the ribs at 2.8".

I'm thinking the SC is preset to run no more than 7#s of boost. Hence, the sticker...Do Not Tamper. Preset to run at 7#s helps with liabilities, no blown engines.

I was told, and can't remember who, not to go above 10#s of boost on a stock 2.0L engine. Changing over to the 2.6" pulley, does help with the low end boost. It is noticable.

[connieray]

I am going to be doing a timing belt, water pump, etc. change in November. I think I am going to go ahead and at least go to the 2.6 while I have it apart. Neuspeed says it is a "tight" fit and I will probably have to use a puller which means pulling it. AC compressor has front bearing noise, so it is coming off too. Did you get a chance to look at your throttle cable adjustment? Thanks.

[Supercharged98]

Try to back up on the camera. The pic is too fuzzy. I'll take a pic of mine for ya.

[Supercharged98]

Here's mine...

[connieray]

Your throttle cable is way different then where mine is. Could this be causing the lack of low end? I am going to ask Cueball in CA to look at his and hopefully take a picture. His car was the first NB, I think, to get a Neuspeed S/C, and Neuspeed put it on. His car is the white with flames on the Neuspeed website. Thanks.
Ray Townsend

[Supercharged98]

Could be. You may have too much slack in the cable. Check your vacuum pod (by-pass actuator). It may be out of adjustment. It lets the SC to build pressure, if it's out of adjustment, it will open later and cause it to build pressure slower. And, if it doesn't open all the way, it will never build full pressure.

[VdubOne]

I used to have the neuspeed supercharger, what people do not understand is that the 2.6 pulley kit actually wasn't made to create more power. When you live in the mountains or below sea level, the supercharger has difficulty making more power because of the density of the air surrounding. The 2.6 pulley is for people that live in those areas so they can make the usual 6-7 psi that the supercharger is said to push. Plus a supercharger like the roots-type blower that neuspeed has doesn't really give you that much boost, it will give you maybe 20-30 horsepower. It's a pretty cheap supercharger