In an effort to get a final word on a 19% pulley reduction before I buy I want to know if any one or any one you know has had any problems after doing the reduction in a street only mini. Just every day driving to and from the drudge factory. I would also like to know who long you've been running it with no upgrade to the intercooler. One other thing, did you get a remap and does it really need it. I am leaning to the 17% right now but really would like the lower torque range of the 19.

 

I have a 17%, makes great power, requires a tune, almost running out of injectors with this pulley.

what you'll run into with a 19 is over spinning to SC earlier in the rev range, mine is over spinning at about 6k. you'll also definitely need injectors to keep AF-r safe.

if your not getting torque down low I wouldnt fault the SC, make sure your bypass valve is in order, as well as the general maintenance of your motor. Also a tune will help with low end power.

 

I just replaced my bpv with Detroit tuned bpv really will help with low end boost. before dt bpv I only was hitting 8 lbs

I have altas original version 1 pulley putting out 16lbs of boost.

 

Stick to 17.... ! 19 will generate too much heat and over spin the SC. Also, you will NOT (I have installed and know of many cars with 17s and no remap) need a remap for the pulley but you will not get the most out of it until you get one.

 

I've been happy with the 19% for the past 3 yrs and around 40K miles. Stock IC, but switched to JCW injectors shortly after moving from a 15% to 19%. I think you are skating on thin ice in terms of AFR with the stock injectors/19%. Really depends on how hard and how often you push it. I doubt that the necessity of a tune is much different between the 17% & 19%.

Only problem I've had is some belt slippage if I don't change the belt at least once/yr. The 17% should be safer in that respect. But, the difference in heat & over-spinning between 17% & 19% is really minor compared to either of these and the stocker! Funny to me how people think the last 2% is going to make a major problem while the first 17% is not. Then again, I have a spare SC on the shelf just in case.

 

I run a 17% reduction...It ran good before I added JCW380 injectors...but I know it was lean at higher RPM's....After I installed the JCW380's (no tune initially), my car ran smoother, pulled harder, and was more drivable (even Jan of RMW said that JCW380's and the 17 are a pretty good match before a tune, unlike with the 15%+JCW's were they run way too rich at WOT). After the tune, the power is up some more...Torque is better, MPG is better, and my trip computer is accurate now. That and now my car runs smooth as silk!! A win, Win IMO.

Would the 17% have been fine without the bigger injectors and tune?
I'm sure it would have been fine...MANY folks in my local club have 17%'s...many upgraded from 15%'s. But with me being me, I wanted to be 100% sure that I was not causing any damage from running too lean.

Remember, Both Supercharged and Turbo motors like to run rich...IF you run lean, valves can be burnt, or pre-ingnaition, or detonation can occur.....and even though it was likely only lean at high rpm's, I did not want to worry about pushing it hard on occasion!!

 

Peak power output (horsepower to the ground) is the same from the 15%-19%, and can be argued that 11%-19%. Peak power comes in a lot sooner on the curve though moving up the reduction range. This is roughly what you look at in regards to the pulley of choice.

Second thing to consider is by how much you feel comfortable exceeding the stock units speed, that is, much anything over 11% puts it out of its efficiency range, and contributes to excess wear.

- Matt

 

Been running a 19% pulley with stock injectors, intercooler and tune for about 35k miles with no issues (closing in on 80k miles now) You'll see best results with bigger injectors and a tune though...

 

By the way, I just found the perfect belt for the 19%: Dayco 5060535 (53.5"). I had been using the Gatorback 4060537 (53.75"), which is what mostly gets recommended. But with the Gatorback, there was only a partial hole showing on the tensioner when the belt was new, and over a day or two, the hole would sink and disappear. With the 1/4" shorter belt, I now have a full hole showing on the tensioner, and its been 3 days.

 

Been running a 535 on my 17% for a few years now. It is what I normally recommend.

 

Yup...the perfect belt on a 17%!!
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