simple upgrade that works for Festivas ONLY

[FestYboy]

can't remember if i posted this on the new site or not but it was mentioned on the old one: swap out the stock rockers for the roller tip style from later aspires. this works fairly well and is cheep (~$25). the "butt dyno" reports about 3-5hp gain due to less friction and higher ratio (more lift). this mod will work best with cams from carbureted Festys as they have longer duration than the EFI ones. the cam and rocker combo will work with EFI cars as well, you just need to find the cam.

next up is a DIY adjustable cam gear.... FOR FREE!!!, stay tuned.

[fastivaca]

Hey Arty,

Would this work on a formerly carbed B6, the one your intake manifold came off. It currently has the old style screw & locknut valve adjustment.

So, could I pull the rockers from an Aspire B3 and transplant them to my B6?

I've already picked up a complete EFI intake manifold and the correct TPS. I also picked up a two plug ECU and B6 distributor from one car so they "match".

Thanks

Ian
92 GL Sport.... B6 transplant creeping closer
Calgary

[FestYboy]

why yes, yes it will work, cuz that's what my setup is right now. save for a collapsed lifter, it works great.

[ericsmith32]

What I find odd is that the aspire is rated at the same horsepower numbers as the festiva but the better roller rocker setup if added to the festiva adds a couple horses. Something doesn't quite add up. Is the aspire detuned or something?

[fastivaca]

One thing that might hold back those extra horses in the Aspire is that the exhaust manifold is more restrictive than the Festivas.

[ericsmith32]

I need to look at that. The aspire header looked less restrictive from the outside.. didn't look on the inside. The aspire header is much lighter though.

[B6T]

And can you verify that there is an actual change in rocker arm geometry (you said the ratio was different)? I'd hate to see people go through all this work and find out that it wasn't worth it.

[FestYboy]

about the aspire manifold, it IS more restrictive than the festy's at the collector. the festy's cast iron manifold also retains heat better, improving the gas velocity out of the ports. i also compared an aspire cam to a festy EFI cam and the profiles and lifts are different (minor changes) the carbed cam on the other hand has lower lift (i think i measured a .020" difference) but the duration is several degrees longer.

as for the rocker ratio, i know that i measured the aspire rollers to be longer, i just can't remember the amount (note: it's NOT a drastic improvement but it's there) as besides, the rollers are the most important part. less friction is ALWAYS a good thing.

[ericsmith32]

I'm having a hard time believing that the aspire's header is more restrictive.. i'll compare the two in a couple weeks. Until then I call :bs: ... if someone wants to post pics go ahead.

[FestYboy]

FB71 wrote:
DO NOT use the Aspire rockers with the Festy cam shaft!

you NEED the Aspire cam.

the festy cam lobes are ground on a slight bevel to reduce rocker pad wear. this will cause the Aspire rockers to 'side load', meaning, they will be pushed off to one side, grinding the rocker body into the rocker shaft towers. Also, the lobes are made of a different material. The iron cam in the festy is too soft, and the rollers will eventually wear a trough in the lobe, destroying both the cam and rockers. The aspire cam is made of steel, specifically to prevent this.

well, he's right about the cam being soft and the rockers wearing through, BUT i have some problems with the reason it happened.

let's start at the beginning, when i first did this mod i was using a stock cam and springs. I put about 8k on the engine before tearing it down for the B6. during the disassembly i measured and inspected the cam to compare it to the new one from FMS. At this point there was no noticeable wear on the cam lobes at all, so i assumed things would be OK for the B6.

fast forward to now: The B6 received the FMS cam and heavy duty springs and the same aspire rockers from the B3 were put in. today i inspected the cam after about 8000 miles on the engine and discovered that 5 lobes were severely worn!! i believe the reason it happened to this cam and not the stock one is the heavy duty springs. the added pressure and the fact that it was being applied to a smaller surface area must have been the cause for the wear.

i think the stock springs are all that the festy cam can handle when mated with the aspire rockers. more testing will need to be done to prove this theory.

now my goal is to find a cam that will handle the combination of heavy duty springs and aspire rockers. I'm going to have a stock cam heat treated to see if it hardens the surface enough, and if that doesn't do it I'll take another one and have it cryo treated to see if that works.

[FestYboy]

I'm having a hard time believing that the aspire's header is more restrictive.. I'll compare the two in a couple weeks. Until then I call :bs: ... if someone wants to post pics go ahead.

well figure this, the festy manifold is a cast piece and all 4 ports flow in a downward curve toward the down pipe. the aspire manifold has 2&3 curving down like the festy's does, but 1&4 face each other in a horizontal fashion, to me that's a restriction.

[FestYboy]

[JerseyJay1.8T]

dude, without a dyno comparison, or at least some more detailed tech information than an MS Paint drawing, you should really hold back from saying that anything is a "definite" gain. And just because the rockers are longer doesn't mean they're a different ratio... they need to be longer from the center pivot. Without teching them out against the festy rockers, you have no proof of anything being different except the rollers and overall length. As for the manifold, without some kind of dyno comparison or flow test, again, just because the festy manifold LOOKS like a better design doesn't mean it IS.

[FestYboy]

dude, without a dyno comparison, or at least some more detailed tech information than an MS Paint drawing, you should really hold back from saying that anything is a "definite" gain. And just because the rockers are longer doesn't mean they're a different ratio... they need to be longer from the center pivot. Without teching them out against the festy rockers, you have no proof of anything being different except the rollers and overall length.

well, let's see, i like to use top speed and acceleration times as a measurement of gains or losses. at the time i put on the rocker mod, i had a top end of 72 before and 85+ after on the same stretch of road, so that indicates a gain. as for the rockers, both the festy and aspire HAVE to use the same center-line and pivot to cam length so any change in length HAS to be a ratio change.

THAT'S MY PROOF

[JerseyJay1.8T]

and that's still not proof.... :roll: Maybe if your trap speed was based on a 1/4 mile track where at least there are fewer variables, but a 13 mph gain is more than I got out of an additional 14 lbs of boost and a 700 rpm higher redline in my beetle. Logic states that something that might add 2-3 hp isn't going to net that much of a gain. Scientific proof requires eliminating as many variables as possible, not just blasting down a road and reading info from what could be a wildly inaccurate speedo while trying to drive...

I'm not saying this to be argumentative dude, so don't take it like I'm calling you out. I'm not saying that its not a gain, i'm not saying that it is... I'm just saying that you need a more scientific test to really say WHAT it is. Proof relies on quantitative, objective, and precise data.