GSXR Cams and CDI

[bandito93]

I am looking to get some more power out of my Bandit aand I have heard of people putting GSXR cams in their B400's. Well I have done some searching and found a couple of sets but I am not sure what series of Gixxer 400 cams will fit the bandit. Is it a GK71, GK73, or GK76? Also I wanted to know if it is possible to plug in a GSXR CDI to match those cams, and what gen GSXR i would need to get that from. I know there is gotta be someone on here who knows the answer and your help would be really appreciated. Thanks guys -Riley-   

[Garyola]

If you want more real, noticeable power, get race carbs. It will jump the hp by 4 or 5. Hp is very hard to get. The cams will make marginal difference for the effort. I've done a ton of work to the engine in my GSXR400 (bandit engine in it) and I got 59hp at the rear wheel on the dyno. That's about 65hp at the engine. The biggest jump in power was the carbs.

G

[bandito93]

Thanks Gary, you brought up another topic I was going to ask about, the carbs. I want to upgrade them as well but I was unsure what carbs to look at. I have heard Yamaha XJR400 carbs swap in and are flatslide, or I was thinking of looking at GSXR400 carbs, but I wasn't sure if I needed the GK76 or GK73 carbs. Apparently my Bandit already has the 33mm carbs on it because it is an E-28 (Canadian model) so I wasn't sure if the GSXR carbs were any different because I've heard they are a 33mm as well. I have found a few sets of those cams pretty cheap and I don't mind going through the trouble of installing them (I need to check the valve clearances anyways) so even if the gains aren't astronomical any improvement helps. What carbs are you currently running now?

[Chris H]

Unless you are racing the cams will make little difference, the 76a will not fit as the journals are bigger and the 73a that fit share the same exhaust and use a slightly different inlet cam that pushes the power band slightly higher up the rev range, both bikes make the same bhp as standard so no direct increase. As Gary say's the flaties will give more power and another big increase is from a good exhaust (full system) as the standard one has a small pipe inside the collector. Regarding cdi's the 73a will rev a little higher but you need a matching trigger pickup for the year of cdi. My road bike is making 62.8 bhp with fairly heavy tuning using stock carbs and air box, to show how restrictive the stock box and carbs are i hit 62bhp with a small amount of work and no matter what ive done since the main jet size has just not moved altho ive had to up the needles as the mid increased.
I have a 73a sp race bike with mikuni TMR 33mm flatties and the difference these make is amazing.

[bandito93]

Thanks for the additional info Chris, very helpful. I am interested in getting a set of flatslide carbs but a few issues come to mind. First of all can i still retain the stock airbox / airfilter? Second, are there any bikes these came from w/ proper spacing between the carbs? I've heard a Jap spec XJR400 has ones that will fit but I have not heard of any other bikes. Thanks a bunch

[Herr Tod]

A GSXR 400 CDI gives you 500 extra revs before the limiter. That was the only reason I replaced my stock CDI, there were a pair of corners nearby where I just reached the limiter on lean angle in second gear. It annoyed me and going to third gear would be slower

[Chris H]

You could get FCR's in a bandit fit over in Japan, the XJR is very close as to still fit on. think Jay used them because they are more common than B4 fit. From the work on the bike ive done it seems to be the airbox thats the most restrictive part, gets it air from the back and just dont let the engine breath.

[bandito93]

A GSXR 400 CDI gives you 500 extra revs before the limiter. That was the only reason I replaced my stock CDI, there were a pair of corners nearby where I just reached the limiter on lean angle in second gear. It annoyed me and going to third gear would be slower

Herr, did you notice any difference in the powerband besides the extra 500 RPMs with the Gixxer CDI? I'm not to concerned w/ getting a whole bunch of overrev but I was hoping it would give a better ignition curve. I also noticed after installing the GSXR cams that I have a huge flat spot between idle and about 4k. It's only noticeable when pulling away from a stop but I seem to have to apply a lot of throttle to get going and then when it hits 4k it pulls really quickly, even just cruising around town. Not sure if anyone else has hada similar issue. Thanks

[Chris H]

Hi Bandito,
I never fully answered your question- You can run the FCR's with open stacks or unbolt the stack mount and get a kit to fit the B4 airbox, take a look at webike.jp as they sell the FCR's new at mega money and may still have a picture of the box mounts.
The gk73a uses different taper needles to the B4 so you may need to lift or drop the needle to cure the flat spot.