Big Valving a GS1100 4V

[displaced]

what are you fellas using for rear tires/tyres????

[GER144]

I use Metzeler's on just about all my bikes. Metzeler's hook up good. There are many others too. If you have a wide rim (17x6) Shink 003's are great if you have power and want good hook.
On the dragstrip I was using a Mickey-Thompson 26x10-15" out back.

[Big Jay]

Both the 1100 and 1150 heads are woefully under valved.

As an example, the largest valve you can put in these heads using the stock valve location is 31mm intake. A stock hayabusa has 33 mm.

Motors are basically air pumps. The more air you can get in and out, the more power you can make. Knowing that, is is plain to see why all of the newer bikes make way more power.

At the minimum, 1.5 over intakes and 1mm over exhaust should be used for any kind of high performance street bike. This can be done without changing the seats. The 1100 can take 28.5mm intake. The 1150 29.5mm.

Jay