Starace RSR velocity stacks 821/939 install

The RSR velocity stacks from Starace have finally been released. I have been excited about these for some time now. They are made of a nylocarbon material vs the OEM stacks rubber. The OEM are said to distort under mid to high rpm and in some cases cause hot start issue. All I can say if they truly do make quite a noticable difference above 5k rpm. It has the same feel as when I went down one tooth on the front sprocket.

Ok,let's get into the install.
Tools needed-
Allen wrenches 3, 4, 5 and 6mm
1/4in wrench and socket with ratchet and extension
7mm socket
T20 and T25 torques bit
Needle nose and pliers

Up first is to pull the seat. Then remove Allen bolts circled

Can only upload somany at a time.


The radiator is in the way of accessing the front band clamp to the air box trottlebody connection on the right side. Go over to the left side and push the rubber mounted lower support out of its lock then you can push the radiator forward enough to access the band clamp.


Here you will see a couple hoses that need disconnected. If you try to pull the air box with them in place you will break the sensors.




You now have the air box out and can flex the rubber velocity stacks n pull them front the air box. The OEM band clamps need to be transfered to the Starace stacks. Make sure the head of the clamp is facing the right side of the bike when you ace them on the stacks. You will need to apply a thin head of rtv/gasket maker and press the stacks into place. Reach I side the air box and slide the supplied locking ring around the stack up against the air box. Now for the hard part. You will need to install the retaining nut n bolt onto the locking ring and tighten them down. You have very limited access to the nut n bolts so this may take some time. Now you just put it all back together in the same way you removed everything. One thing that I do that aren't always popular is apply high temp brake grease to the mating surfaces between rubber seals, any sealing surface that mates with another and the aluminum of the throtlebody where the plastic sleeve slides over the aluminum. I specifically use high temp brake grease because it won't run when it gets hot, it helps seal, it protects the aluminum from moisture(the first time I pulled the throtlebodies off they were in rough shape due to moisture being stuck in there. It has been perfect ever since I started doing this) it has no impact on rubber(won't break it down like some greases) and helps everything slide together easier. It also doesn't attract dirt.
Anyway, this is the process. You will have a sensor to unplug and disconnect from the air box. The AIS valve sensor. I did an AIS delete a while back so I couldn't show that part.
Now pricing, from what I understand
the filter housing and velocity stacks are 320 euro/$380 shipped
Filter housing alone 230 euro/$273
Velocity stacks alone 150 euro/$178

gatdammit said:

Tim, how long did it take to receive the product? My bike is broken down to this level right now.

Click to expand...

Took about a week. They have been in the works for a year though. He just now started shipping them out. Shipped it from Italy on a Monday and arrived on my doorstep in Lansing Mi on Friday.

gatdammit said:

And he only does business through facebook?

Click to expand...

Facebook messager and email from what I understand.

hyperbruno said:

@Araitim
Great write up as always.
I have termi’s filter housing. It has bigger opening but doesn’t have the inlet design the Starace has.
Do you think that there is good improvements using the velocity stacks with it?

Click to expand...

I do think the stacks will make a good impact with that housing as well. I would it would even make a noticable difference with an OEM housing. The way the air flows into them and the ridged shorter shape has alot to do with why they make the impact I believe.

saken said:

I was thinking of getting his airbox intake mod and Rapidbike evo but it's quite pricey. I might do the MWR mod instead. But while I'm at it I should add these stacks as well. Any idea how to check the butterfly valves and make sure they are calibrated right? Good time to check while doing this mod. Do you just break down the bike to this point, turn on the bike and twist the throttle and look at the bfly valves and eye them to see they are moving equally?

Click to expand...

You would do the mods and then put it back together then take it to the dealer to have the TPS reset. At that point the can give you the values of the resting TPS and tell if it's all ok. Opening up the bike, turning it on and twisting the throttle won't do anything at all.