So what can I do to add more HP? I have been told to change out the SC pulley to something smaller. What size would you all recommend and are their any supporting mods that I would need to get the HP gain. I have heard it can give you an extra 20 HP or so. For those of you that have already done this what kind of gains did you see?

 

There are lots of things you can do to add more horsepower. It just depends how much you want to spend and how much power you want to make.

It is impossible to give you a power gain for a smaller supercharger pulley since there are so many options and it so heavily depends on what other mods you may have. A 3.5" vs a 3.0" give much different power gains, but a 3.0" on a stock engine will chunk pistons and blow it up.

If you have a general idea of what set of mods you're looking to get, we could give estimates of that.

The key with messing with the supercharger pulley size is to know how much KR the engine currently has (you can use any compatible scan tool to find this- check under high load conditions, WOT in 2nd or 3rd, etc). If you have KR now, spinning the supercharger faster will create more heat and more knock which in turn pulls more timing and could make you lose power in the end.

Ideally you want your KR value to be virtually zero before and after the pulley. A couple degrees isn't going to kill you, but if you've got 5+, I certainly wouldn't change pulleys until you do something to lower it.

Ways to lower it include airflow mods (cam, headers, ported heads, etc etc) and intercooling (either via meth or an intercooler.

 

Here is a good thread that should answer all your questions. It helped me figure out my plans for the future.

https://montecarloforum.com/forum/fw...n-3800s-10942/<-- link

 

Here are the mods I have now. I have a 2.5" flowmaster catback exhaust with super 40s mufflers, K&N Cold Air Intake. My speed daddy headers will be installed this week. Then next week I will be adding a magnaflow highflow cat and doing a ubend delete and qtp exhaust cut out. I do plan on getting at least the stage 1x camp from intense racing along with the valve springs

 

For all practical purposes, the k&n and catback add no real power. The headers will definitely add power, especially with tuning, and would theoretically let you drop sc pulley sizes to pick up even more. I'd say the safe bet out here (between the crazy summer heat and crumby 91 gas) would be to go to a 3.5" pulley. With tuning, id guess you'd be somewhere around 250 whp.


As for your mod plans, I do want to make a couple of points:
-you say you're installing speed daddy headers this week and a cat/ubend delete next week. If the speed daddy headers are like I remember, they already include a downpipe section that deletes the cat and stock ubend.
-I remember you said a shop was going to put the headers on, but I doubt you'll be able to wait to put the cat on unless they temporarily weld up your stock one. Most legitimate shops wont risk knowingly deleting a cat since the fine to them is huge.
-for the cutout, keep in mind that it's really going to be mostly for sound, you're not going to pick up any real horsepower. The headers will provide the bulk of the exhaust power gain, and you already have a higher flowing catback, so there isn't much left on the table for exhaust power without getting the engine to ingest more air first.


If you really plan to do a cam down the road I'd suggest going with a modular pulley system from the start. They're about twice as expensive as a regular pulley, but its really a pain to press pullies on an off. With a modular setup, you just remove the belt and take off a handful of bolts to change the pulley.

 

Throw a 3.4 pulley and get a tune. That's a drastic difference in power you'll feel. I'd also invest in a gauge to read your KR to make sure you're safe on that pulley drop.

 

Also suggest a 3.4 pulley. But before doing the pulley the headers need installed, colder spark plugs need installed and as soon as that pulley goes on you NEED to tune it

 

How do you measure KR? My friend has an OBD2 scanner that I have access to or is there something else I need?

 

Aeroforce Intercepter Scan Gauge

There's the link to a gauge that can read KR and many many more things you'll need depending on how far you're planning to mod. Love that gauge, definitely worth the investment. Doesn't look like a link but just click on it it'll direct you to the webpage.

 

I am running two aeroforce scan gauges, there amazing!