Kenne Bell 11#pulley

[Nitrous2V]

Well I am to use to my 9# pulley and want to upgrade to a 11#. How many of you have upgraded to this size with a stock block and had no problem? And is the change of the pulley size very noticeable?
Second question I have is- is it common to see your boost gauge vary in its output. For example on a hot day or humid the best boost I can make is 9 which is normal for a 9#pulley but when it is cooler outside and the humidity is low I have seen 14# on the gauge and the power is very much noticeable. Is this normal or do i have problem with my boost gauge.

 

[tooblue02]

KB says not to run above the 9lb on pump gas, I have a 10lb in the car but have never used it. My boost varies from 9 to 10 depending on the weather and there is a huge difference in the performance. At 530 am it is alot of fun but when it is about 4 pm the temp and humidity are so bad that there is probably a 50 hp decrease. Weather has a much bigger effect on a supecharged car than a N/A car.

 

[Nitrous2V]

thanks for the input. I will stick with the 9# pulley for now.

 

[Defleshed]

yeah it may void the warrenty, not to mention screw things up. stay on the safe side for now

 

[el_kid_1]

I just installed the 10 psi pulley today. I'm running on 93 octane and hence should be on the safe side. The 11 psi pulley I'd say is pushing the envelope...too risky for a stock block/ineternals.

 

[kirkyg]

KB says not to run above the 9lb on pump gas, I have a 10lb in the car but have never used it. My boost varies from 9 to 10 depending on the weather and there is a huge difference in the performance. At 530 am it is alot of fun but when it is about 4 pm the temp and humidity are so bad that there is probably a 50 hp decrease. Weather has a much bigger effect on a supecharged car than a N/A car.

Actually thats not entirely true.

KB says that the tune for the 9 pound intercooled kit is for 91 octane or mid-grade fuel. So if you use their formula you can get between 10-11 pounds on 93-94 octane gas. Remember the higher octane gas the slower the fuel burns and more pounds of boost you can push. Also, the lower your compression ratio is the more boost you can handle. So see if you can get ahold of some 94 octane if not 93 should do ok and try 10-11 pounds.

What worries me is that your guage is reading 14lbs on a cool day that just doesn't seem right. I can see maybe .5-1 pound boost different between a very cool no humidity day vs hot smothering day with lots of humidity, but i dont see how it could be 4 pounds of boost difference.

kirkyg

 

[Dan_Soprano]

I have a 10lb in the car but have never used it.

Same here. I am going to the dyno tomorrow though to give the #10 a run. I'll post the results tomorrow night!

 

[kirkyg]

should gain about 15-20 rwhp from 1 pound of boost right?

 

[tooblue02]

Actually thats not entirely true.

KB says that the tune for the 9 pound intercooled kit is for 91 octane or mid-grade fuel. So if you use their formula you can get between 10-11 pounds on 93-94 octane gas. Remember the higher octane gas the slower the fuel burns and more pounds of boost you can push. Also, the lower your compression ratio is the more boost you can handle. So see if you can get ahold of some 94 octane if not 93 should do ok and try 10-11 pounds.

What worries me is that your guage is reading 14lbs on a cool day that just doesn't seem right. I can see maybe .5-1 pound boost different between a very cool no humidity day vs hot smothering day with lots of humidity, but i dont see how it could be 4 pounds of boost difference.

kirkyg

Mine has been tuned for 93 so I guess I really didn't think about that, but stil 91-93 is not too much of a difference and I would still use race gas when going to a higher boost level, just so I don't leave my stock internals behind when I take off.

 

[el_kid_1]

Actually thats not entirely true.

KB says that the tune for the 9 pound intercooled kit is for 91 octane or mid-grade fuel. So if you use their formula you can get between 10-11 pounds on 93-94 octane gas. Remember the higher octane gas the slower the fuel burns and more pounds of boost you can push. Also, the lower your compression ratio is the more boost you can handle. So see if you can get ahold of some 94 octane if not 93 should do ok and try 10-11 pounds.

What worries me is that your guage is reading 14lbs on a cool day that just doesn't seem right. I can see maybe .5-1 pound boost different between a very cool no humidity day vs hot smothering day with lots of humidity, but i dont see how it could be 4 pounds of boost difference.

kirkyg

I agree and here is the math to prove it. On our kit, each psi of boost requires approximately 1.5 octane over 91 octane. If 93 octane is available, like my case, then (93-91= 2 octane) divided by 1.5 octane per psi of boost = +1.3 psi of boost. Thus, I could increase the boost to 10.3 psi (i.e., 9 + 1.3). This is why I ordered the 10 psi pulley. As a precaution, everytime I fill up my tank I put in a can of octane booster (my car sees less than 2,000 miles a year). When I go to the track, I also put in a couple of gallons of 100 octane gas. Just because I don't want to break my motor just yet. Hope this helps!

 

[el_kid_1]

should gain about 15-20 rwhp from 1 pound of boost right?

Yup, KB claims gains between 17 and 20 rwhp for each additional pound of boost.

 

[tooblue02]

I agree and here is the math to prove it. On our kit, each psi of boost requires approximately 1.5 octane over 91 octane. If 93 octane is available, like my case, then (93-91= 2 octane) divided by 1.5 octane per psi of boost = +1.3 psi of boost. Thus, I could increase the boost to 10.3 psi (i.e., 9 + 1.3). This is way I ordered the 10 psi pulley. As a precaution, everytime I fill up my tank I put in a can of octane booster (my car sees less than 2,000 miles a year). When I go to the track, I also put in a couple of gallons of 100 octane gas. Just because I don't want to break my motor just yet. Hope this helps!

only problem is that my KB is so damn efficient, that the 9lb pulley made 10.5 lb's of boost on the dyno so I figured the 10lb should make roughly 11.5 lb's of boost so I opted to be safe and not run it. That and it is way to freakin hot to be running like that on the street. I just hit 12K (since the end of feb 04) with my KB and I want it to last. But it's your car so go nuts, just be ready if she blows

 

[Defleshed]

only problem is that my KB is so damn efficient, that the 9lb pulley made 10.5 lb's of boost on the dyno so I figured the 10lb should make roughly 11.5 lb's of boost so I opted to be safe and not run it.

WOW that is nice!

 

[el_kid_1]

only problem is that my KB is so damn efficient, that the 9lb pulley made 10.5 lb's of boost on the dyno so I figured the 10lb should make roughly 11.5 lb's of boost so I opted to be safe and not run it.

You're lucky!

 

[showstopper2]

not to sound stupid but why fear the boost over 9lbs with 93 octane? I don't have the KB but do have a P1SC-2 which see's the high side of 13lbs with the stock pulley on a stock 04GT with 93 octane without any issues. my biggest problem is the belt starting to slip near my shift point of 5800rpms. I have a real safe tune on the car for daily driving but she still makes plenty of power. I don't see why you guys shouldn't be able to do it too???

 

[kirkyg]

not to sound stupid but why fear the boost over 9lbs with 93 octane? I don't have the KB but do have a P1SC-2 which see's the high side of 13lbs with the stock pulley on a stock 04GT with 93 octane without any issues. my biggest problem is the belt starting to slip near my shift point of 5800rpms. I have a real safe tune on the car for daily driving but she still makes plenty of power. I don't see why you guys shouldn't be able to do it too???

Well there is a price for boost off idle...its extra heat and can cause problems if the vehicle isn't tuned just right.

kirkyg

 

[el_kid_1]

not to sound stupid but why fear the boost over 9lbs with 93 octane? I don't have the KB but do have a P1SC-2 which see's the high side of 13lbs with the stock pulley on a stock 04GT with 93 octane without any issues. my biggest problem is the belt starting to slip near my shift point of 5800rpms. I have a real safe tune on the car for daily driving but she still makes plenty of power. I don't see why you guys shouldn't be able to do it too???

I guess I'm just a bit paranoid when it comes to increasing the boost even if it's just one pound increase. I don't wnat to break my motor just yet.

 

[YellowJacketGT]

not to sound stupid but why fear the boost over 9lbs with 93 octane? I don't have the KB but do have a P1SC-2 which see's the high side of 13lbs with the stock pulley on a stock 04GT with 93 octane without any issues. my biggest problem is the belt starting to slip near my shift point of 5800rpms. I have a real safe tune on the car for daily driving but she still makes plenty of power. I don't see why you guys shouldn't be able to do it too???

I had a Vortech 14# now have a KB 14#.. About same HP SQ 441/KB 447..

Only saw max boost at high RPM with Vortech.. KB instant boost as soon as you hit WOT..

The issue with more boost is heat. The longer you are in boost , the more boost you have more heat gets generated.
Even with Larger Heat Exchange (Gords/2fans) and larger water holding tank. The temperature increases from 130 - 160 degrees through 4 gears. The intercooler can hold about 2 gears , after that is all over.

I could run all day long at the track with the vortech. Can't do the same with KB... Unless I water inject or small shot nitrous.

I would be carefull with increasing boost. Probably will have to reduce timing to minimize detonation. I know I've been their. Not on the first 4 gear run, but on the second or third...
I plan to use some race fuel at the track just to be on the safe side...