B12 bst36's on a 1127 powerscreen

[Charlie]

Has anyone fitted b12 bst36's on to a 1127 powerscreen and with what results? Any loses in low/midrange? Any dyno results before and after? Cheers

[Sam-Jaffa]

Following this with interest

[wraith]

Don't know about the 36mm carbs, but I have fitted the gsxr 38mm carbs on my gsx1100 power screen with no lose of bottom/mid as that comes from the cams (let the argument start on that one ) but it gave the motor a lot more top end at lower revs.

[Captain Chaos]

same here, 38's on the 1100F engine. More power all over the rev range.

When I had 36's the gains were a bit smaller but still no loss of bottom end when set up correctly.

 

[Charlie]

Ok excellent cheers guys thanks for that, will give the 36's ago for now as already have them.. Its currently running a custom 4-2-1 exhaust velocity stacks with fine mesh gauze (due to space, powerscreen engine in the wrong frame ;-) ) stage 3 jet kit  bst34's, compression ratio upped to 13:1 with dialled in cams... Currently making 117 rwhp & 75ft/lbs.. Any idea on gains with 36's??? 

Edited October 24, 2016 by Charlie
Grammar

[Oilyspanner]

Your bike is only producing standard type power, they should produce more than tat with more compression and freer flowing, calibrated carbs - is the exhaust restrictive ? Yours should be into the 120s and with compression that high torque should be bumped up to over 80 lb/ft. How much of a boost depends on what's keeping the power lower than expected at present  - could be just a low reading dyno I suppose.

I've seen a few 1100F engines pumping out over 120 with very few mods , P.Bikes had one with 36mm carbs (in GSXR750L)in the mid 90's that put out 124hp and that was with a Motad exhaust , not a high performance one, with  no other mods.

[Charlie]

Oh ok interesting.. Currently has a 60mm diameter link pipe and end can on it which I don't think is helping (going to drop down to a 50mm end can & put the bst36's on and set up with a jet kit etc etc see if that helps. 

 

[Oilyspanner]

A good header and collector section is a must for good power Charlie and after that a 50/51mm (id) link section / baffle seems to work well. The 1100F wasn't shy on the power front, it wasn't restricted like the GSXR1100L,M,N,(restrictive silencers) but the smaller carbs knocked some hp off the top and with slightly softer cams getting 130+hp isn't easy as on the R's.

I'll see if I can look out that article tomorrow - John Robbo enjoyed the 7/1100f

[Charlie]

Ah yes it could well be the headers that are robbing some of the power, the full 4-2-1 system was made by nrp in Newark.. In comparison to some b12 delkevic 4-1 headers I have on a other project, the nrp headers are much bigger diameter maybe to big? 

[Captain Chaos]

11 hours ago, Charlie said:

powerscreen engine in the wrong frame ;-)

the only wrong frame for a powerscreen engine, is a powerscreen frame. Big heavy motherf*ckers.

Mine had 38mm carbs, full Termignoni 4-2-1 and 3 degrees ignition advance and gave 125hp at the wheel. Yours should give more than that on 36's.

[Oilyspanner]

1 hour ago, Captain Chaos said:

the only wrong frame for a powerscreen engine, is a powerscreen frame. Big heavy motherf*ckers.

I had to quote that !! - dead true, a waste of a good 1127 engine -  like pulling around an extra 25kg sack of potatoes all the time.

[Charlie]

Totally agree, said powerscreen engine is actually in a 1982 Gurls blouse cb750 frame with bandit running gear brakes etc.. 

Mainly used for hill climbs hence not wanting to lose any low/mid range, does however have a day time MOT so occasionally used on the road.. 

[clivegto]

My one this summer made 125hp 1100f standard motor, 36mm b12 carbs stage 3 dynojet kit with standard b12 air box rubbers, ram air socks & a full yoshimura  exhaust.

Edited October 25, 2016 by clivegto

[Oilyspanner]

That's really nicely done CGTO - I would never has thought a Blade rear end would look so at home on a Slabbie frame, I'm seriously impressed and I like more standard type bikes......

Top marks that man !

[caferacerdan]

13 hours ago, Charlie said:

Totally agree, said powerscreen engine is actually in a 1982 Gurls blouse cb750 frame with bandit running gear brakes etc.. 

Mainly used for hill climbs hence not wanting to lose any low/mid range, does however have a day time MOT so occasionally used on the road.. 

how to make a Gurls blouse better...put a proper motor in it!

[Charlie]

9 hours ago, clivegto said:

My one this summer made 125hp 1100f standard motor, 36mm b12 carbs stage 3 dynojet kit with standard b12 air box rubbers, ram air socks & a full yoshimura  exhaust.

Very nicely done like it, the yoshi exhaust is beautiful. 

[Sam-Jaffa]

i dare say it but i quite like that H**NDA......i'll get my coat

[caferacerdan]

2 hours ago, Sam-Jaffa said:

i dare say it but i quite like that H**NDA......i'll get my coat

your not the only one...I think we get away with it though as its now technically a Suzuki by heart!

[Charlie]

Does anyone know what the optimum header diameter is for these motors 36mm or 38mm?? The custom made system that's on it has 42mm headers which I'm pretty sure is what's causing it to be down on power.. 

[Gixer1460]

Way to big! 36mm will work ok with a stock engine, a modified one will benefit from better breathing 38mm dia. but compared, will lose a bit of torque through potentially slower gas speed / cylinder scavenge.

[Charlie]

Ok excellent cheers for that, going start looking for an alternative 36mm set of headers now.. Got a b12 sump pan and pick up now also so few more options.. 

[Longhair]

I'm running bst36 carbs in my 1127f bandit. Its got a stage 3 with k&n twin ovals and needles on 2nd groove. Exhaust is motard headers with small micron gp style can off a gsxr 600. Not sure about HP but it pulls clean right through with no flat spots at all.