Fit Yoshimura ST-1 Cams

[Starion VR4]

So after all the buggerisizing around... how does it go?

[northern]

So fare not really fast... 
Engine is still of the bike - I have ~2 months, before weather would allow me to go for a ride.

First ~500-1000 km I would try to go easy on the engine, to brake-in new cams. Then oil and filter change and after that dyno tuning and measurements.
In the middle of the July, there is streetfighter bike rally, where is open drag strip with proper telemetry. After that I will answer your question

[T 24]

Ok, I know this is not Yoshi thing, but cam swap anyway...
I changed my std exhaust cam to std intake cam, to get more lift and duration to exhaust side for my turbo application. Now I have symmetrical cams.
I also fitted adjustable cam sprockets to both cams. I made them from old cam sprockets by milling long holes.
Also I had to make new timing marks to exhaust sprocket.
Lobe centers I set to 110°/110°.
With valve clearances was easy, because the base circle is the same in all std safts. All exhaust clearances were between 0.24 and 0.26mm and intake 0.11 to 0.12mm.
I did nothing to them.
Only small problem was the weather: this morning there was -24°c in my garage. Tools were cold...

[KiwiCol]

-24 FFS!!!  Jeez, can't you move to a warmer climate?     My Freezer only runs at -18 - -20!

We were sayin the other day how 'hard' the Aussies' are, reckon you've just taken the cake there T24!  No competition. 

[northern]

@T 24
good engineering. Would be interesting to know, how will it affect performance.

[T 24]

Almost the same answer than yours northern, about two months, then I can start testing..
But this same swap is commonly used in turbo hayabusas and it works, giving 20-40 hp more with the same boost (in busa).
And about 10 hp in N/A engine (busa).

[seth]

Just found this email thought it was lost as it was on the old org.
Its a comparison between yoshi st1 cams.
And a regrind of standard cams by Kent cams.
Both give very simular high bhp and torque numbers
Both bikes were ran on the same dyno on the same day so is a very good comparison.
The yoshi's are blue lines and Kent cams the red.
Both bikes felt great on the road but the yoshi cams pulled much stronger in the mid range where you acctully ride the bike as seen in the graph
My graph is now even smoother as it was re-dynoed after fitting the pod filters but no extra bhp .

[T 24]

@seth. You may be correct with that comparison and probably you are.
But unfortunately nothing is so simple.

Those two bikes, did they have the same exhaust system? Air filter? Fueling, PC, maps? Age, 16 or 32 bit ecu?
Cam lobe center settings?
We know that stock yoshi has 105/105°, what Kent Cams they were and what timing?
I can see, there are small differences on AFR curves.

Couple of years ago Mr. Jack Frost from Holeshot Racing told me that the huge difference between their GSX 1400 stage 1 and stage 2
turbo kits comes only from cams, 200/250 RWHP, and Kent Cams is making those cams.
https://www.holeshotracing.online/pdf/turbo-pricelist/tbikesuzgsx1400_160924.pdf

Then Mr.Tony Woodward from Kent Cams told me what they are and what are the lobe centers.
I told him my own suggestion and his opinion was that it will work, but he can't give me any timing advises,
because there is no timing marks for that cam and the job has to be done by using dial indicators.
And it really works! I don't know the numbers, but it works!

So nothing is so simple.

[seth]

Hiya
Both bike were running very simular set ups  both were k6's (same airfilters and same pc111 usb) only differences were I had and akroprovic the other bike a yoshi  exhaust  and both ran custom maps to suit that were set up on the same dyno
Timing for both sets of cams was standard both cam sprockets were standard and unmodified .
The slight dip you see in the Kent cam graph mid range also transferred to the road where in a totally unscientific test we did rolling full throttle acceleration test from 30mph and 40mph my bike pulled much stronger.
We swopped bikes to ride and the test were the same my yoshi bike pulled stronger when Mike was riding it.

Both bikes felt smooth and pulled much better and felt lots more responsive than a full standard bike (emma's gsx1400) when ridden back to back with it.
The main thing is just to show differences between regrind of standard cams and yoshi cams .
The main thing was with Kent cams being a regrind of the standard cams the lobes were much smaller with different profiles to standard with the higher lift being managed by using much thicker shims .
Hope that explains what I was trying to show.
I've also seen where guys with turbo motors are using exhaust cams as inlet cams and getting a good amount of extra bhp I'd be very interested in finding out how and what it achieved as if it's all very topend bhp gains it not really what I'm looking for.
I think I said in my post that once you start going very quick on a gsx1400 the handling goes to pot very quickly .
My bike is mainly about the extra bhp and torque in the lower and mid ranges where the bike is mostly ridden and the benefits of all the work are most useable in the real world on normal roads while keeping the bike as user friendly and reliable as possible .

[T 24]

I understood your point. And I believe you are correct in that Yoshi vs. Kent thing.
I just tried to tell, that there can be so many things that matters, making comparison difficult.
Your road test, with changing riders, tells all we need to know
( if you had the same number of teeth in your sprockets, and i think you had)

[seth]

Yes both bikes were running standard suzuki chains and sprockets at the time both bikes were at about 6000miles from new.
So many things change
I.E.
Same bike on same dyno on different days depending on atmospheric conditions give very different power outputs though I belive the graphs are quiet simular in shape.
I put my bike on a dyno in Denmark a whole ago and it had 140bhp but my mates standard 1250 bandit had 105bhp they only come with 98bhp and the guy said if it broke 100bhp we'd get a free beer.
So it was obviously reading slightly high ( not a bad thing when promoting your tuning business).but ok if all the bikes are running on the same dyno then they all run slightly higher or lower figure depending on how the dyno is set up and reading.

The guy who we were at (HMD dynos in cromarty in the highlands of scotland) says he has had so many bike from south dyno's up to tune/set up that have slightly lower readings on his dyno they get annoyed but are happy there bikes ride much better and then give the higher figures when back on the dyno's down south .

[T 24]

I know, there are big differences between dynos.
I have 116 hp and 134 nm in my dyno papers (and in my MOT papers too), and I'm happy with it. It's enough for me 

[GSXKING]

Irrespective of how much horsepower your bike produces, the truth is if you don't rev it to that point all the time it's more about the torque your bike produces that fires you out of the corners. Those who ride GSX1400 are only to well aware of the way they pull from low revs all the way to redline. 

[Shifty]

Does anyone know the full specs of the stock cams and/or the yoshi cams?

Very interested to know durqtion, advertised duration, and .050"/1mm lift.

[Masterbates]

Does anyone know the full specs of the stock cams and/or the yoshi cams?

Very interested to know durqtion, advertised duration, and .050"/1mm lift.

Is this what you are after?
https://shop.yoshimura-jp.com/en/product/syousai.php?id=871