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VS cam pulley size?



Swiggles said:
well i also have a set of 1.8 yella terra rockers, would you suggest those over the 1.7s then?
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If I were you I'd go with the 1.8YT over the 1.7's...That's just me though. The only downfall that I'm running into is that I may have to order custom pushrods to maintain the correct geometry.



Stock rockers and aftermarket rockers have a fixed fulcrum. The ratio is not variable (and if it is it's news to me too).

Judging by your calculation of 1.78 ratio that is what the effective ratio would be with the VS cam and stock rockers combined......
ex. If you were to ditch the XP cam and order custom rockers to give the same lift as the cam you would need to order 1.78 RR.

Lift is calculated by Cam Lift x Rocker Ratio = Total Lift
VS: 206/216 .320/.317 115 N/A Total lift = .512/.507 (.320/.317)x 1.6(stock ratio) = .512/.507
VS w/1.7RR: 206/216 .320/.317 115 N/A Total lift = .544/.539 (.320/.317)x 1.7(aftermarket rocker) = .544/.539
 
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I suggest stock... They were good enough for the highest WHP from a m90, turbo, and CSC... They are probably good enough for you.

The only downfall that I'm running into is that I may have to order custom pushrods to maintain the correct geometry.
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Fail... "Rocker geometry" or whatever you are talking about has nothing to do with pushrods. The only time you need custom pushrods is for custom rocker height or a funny camshaft to pick up slack created by your lifters.

If you were to ditch the XP cam and order custom rockers to give the same lift as the cam you would need to order 1.78 RR
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Uh... Duh?
 
If you're looking for "reliable" then I'd stay in the 3.0-3.2 range. What you really want to pay attention to is your boost level as it can change pretty drastically with the weather.
If you want to see what the car makes with various pulleys, I have a hook up for dyno time.
$90 for an hour, $150 for 2 hours, or $50 for 3-4 pulls.

Quincy is only an hour and a half away.
 


I think the real question here is.. if you get free dyno runs, why are you on grandprixforums asking people what pulley to run? You should be on the dyno figuring it out ;)
 
lol well i will be doing that eventually. i was wondering where to start with this cam. and its not available whenever i want, its kinda hard to schedule most of the time.
 
I'm looking at putting 3.2 or 3.1 on. This is my daily driver, I want to run it 7 days a week. I looking for safe and repeatable.
 


And what if i said the stock ratio was 1.66?

And the guy above: Hell to the no! for a complete DD as your only car, VS is the way to go!

Make almost as much power, get better fuel economy and have a better low end power curve? I think that makes for a win.

Also requires milder springs so your stock timing chain/dampener will last longer.

SnowFlake said:
I think the real question here is.. if you get free dyno runs, why are you on grandprixforums asking people what pulley to run? You should be on the dyno figuring it out
wink.png
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How is a dyno relevant to a car that spends most of its time out of PE?

Also not worth the cost either.
 
i ran an xp before this, i liked it. got an awesome deal on the vs so i picked it up since i had the cash.

Matt im already running a double roller.
 
matt5112 said:
And what if i said the stock ratio was 1.66?
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Even though that may be the case (forgot that they switched to the 1.66 in 99+model year iirc)...1.7>1.66 and the fact that it's a roller rocker setup which puts less stress on the valve train would be the way to go. There is also the option of doing the 1.8 with his combination. Going from a stage 3 cam to a VS cam to me is a big jump....adding the 1.7 to the mix is nice...1.8 IMO even better. Will Steward ran the VS with 1.8 for a long time before he went XPZ.
 


A double roller still has a life.

Even jason there with his XP cam had quite a bit of play when he took a look at his recently.
 
I have heard from many that an XP/S1X is just find for a DD if you set the idle a bit higher, and drive "normally" enough by laying off the skinny pedal to retain good mpg.
 
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crbquist said:
I have heard from many that an XP/S1X is just find for a DD if you set the idle a bit higher, and drive "normally" enough by laying off the skinny pedal to retain good mpg.
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Just set the idle a litle higher. Tons of cars mine included run a stock chain and dampener. Car gets thrashed daily.

Even as a daily skip the VS, i know the op said he got it for cheap, but an XP s1x is way better as a DD.

OP im on a 2.8 l26 bottom with 11.4afr 17* daily safe tune in the winter. I lean it out as boost drops in the summer and add more timing.
 
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