megabusa or magabusa turbo

[craig-c]

just about to go to the factory to order my megabusa but not sure on the engine options    i have spoken to westfield about this but not much help on the 1300T engine can anyone help me out on this one will the turbo go in the westfield engine bay and am i going to have trouble with fitting the turbo or should i just go for the vauxhall 16v engine and tweek it up.

Craig

[ian crocker]

I've seen the Dax Hayabusa Turbo in action, and on road tyres it just gets loads of wheelspin in any gear when it comes on boost.  Even with slicks it struggled unless the track was in excellent condition.  That was the 370HP version.

Ian

[megabusa]

Stick with the n/a motor, you wont be dissapointed.

[Glen H]

taking into acount that a standard 2nd hand busa engine will cost approx. £3,000 and a further £1,200 to dry sump it then you are talking serious money for something that is an animal out on the track but screams it bo***cks off on the way ther and back and is going to give you serious earache from the missus for carbon seats and no windscreen (evening Jenny) .If you then consider that going for either a 2.0 16v vauxhall or zetec engine you will have to buy a gearbox(£150),engine ancillaries i.e starter/alternator etc(£100),throtle bodies/management(£1500),clutch(£50),ligthweight flywheel(£200?) this still leaves you with £2000-£2200 for the engine which should see you right for a seriously decent motor.

If you were happy to go with lightweight seats,aeroscreen & basic trim levels then theres no reason why you can't do this with a 2.0l engine(unless you don't like the taste of flies!

[DavidBirchZEI220]

Talk to Holeshot racing or TTS about the hayabusa engine.

I think the conversion to turbo is not that difficult and I have been doing some idle research as part of my evaluating an XTR build.

If you are going BEC then the sensible advice would be to start with a normally aspirated engine - perhaps stroked etc to give 225 bhp and then look to turbo if you still need more power at a later date.  If nothing else you will apreciate it more if you have experienced both.  

David

[DavidBirchZEI220]

Another point if you don't want massive power and cheaper option would be a badit turbo.  search Grumpy's bandit on the web - he runs a bike at SantaPod that is turbo charged.  THe engines are very common and stand up well to the turbo without lot's of mods.  Not sure how strong the gearbox is though.  

David

[Ian Gratton]

Hi David,

we seriously thought about turbo'ing our XTR - but it seems that wheels spin would become a major problem - I guess the other issue is that if you get somebody like Holeshot to build you a 1500 overbored turbo busa motor its going to have a very short life.

I guess a busa engine at that sort of tune will have a run life (pretty much as to all race car engines) and it would work out quite expensive to maintain.

It seems Craig and I will be doing 1400cc overbore (new forged pistons and liners) and staying normally asp.  We figured a turbo would give the busa engine a mega shot of torque (which we'll miss from the subarus).  It seems that we can get 20% torque increase from the 1400 kit and we'll use progressive nitrous for the straights  . Std busa engine is said to be fine on 50 or 75 jets.

It also seems that 5th and 6th gear can be a little weak too - it seems TTS and the likes of PowerTec do replacements for these at a reasonable price.

We've updated XTR2.net today with another 5 days worth of build information.  Maybe it will be of use if you are considering an XTR.

regards

Ian.

[catflap]

IN standard trim how well do the busa engines hold up, at 3k a time its not cheep, can they be rebuild like car engins?

Anyone have some handy info on life expecancy (say weekend use and 6 track days a year)?

[Ian Gratton]

We were strongly advised to use a dry sump kit on our car as its purely for heavy trackday use.  It seems that some bike engines don't like the lateral g that a BEC generates as the engine always stays upright (bike obviously leans down into corners).

It adds a heafty cost to the build - but it will probably save numerous engine rebuilds if you don't.

I don't have a clue as to how long the engines last - but if it has TLC and regular oil and servicing I imagine it would be good.

Maybe a long-term megabusa owner would like to comment

Any takers

[SEiGHT]

I've only been on a couple of track days, but at both events the BEC drivers without dry sumped engines were complaining about oil surge. After listening to their comments I would dry sump a bike engine even for normal road use.

As you say, a bike will lean over in corners and the oil flow in the engine is designed with this in mind. BECs are still fairly new designs, and it will be interesting to see if in 12 months time if the manufacturers dry sump by default based on failure rates.

[catflap]

They get used and abused quite well in the host bike, and have a good rep with bikers, but the extra weight and grip of the car could affect things.

Any seasoned busa owner care to comment?

[DavidBirchZEI220]

I visited TTS this morning to discuss busa engines as part of my ongoing research ahead of ordering an XTR.

A couple of comments based on feedback from him.

1) must dry sump but avoid the belt driven versions that were the original design and cause problems - I think westfield factory versions are like this unless they have recently upgraded

2) a 1400cc engine is pretty much as reliable as a stock engine.

3) The turbo conversion is very difficult to control.  160bhp at 6500rpm jumps to 300bhp at around 7500 rpm and there ain't much time to respond if you're in a corner.

4) Change the idler gear.

Having said that I'm still tempted by a turbo conversion !!

[Ian Gratton]

Sounds like a good visit Dave.

I'm sure when I did the inventory of our dry sump last saturday it appeared to be a belt driven pump - I'll check with craig and see what westfield have to say about this.  I'm sure the XTR² sump kit is derrived from the one used on the megabusas.  We have to get a replacement Sump tank from them soon as ours is for the mega - its too tall to fit into the xtrs engine bay.

turbo - heheheheheh    I can't imagine 350 in our XTR - I reckon you could just wheelspin the entire back straight at donington

[Blatman]

It's not lateral forces on a bike engine that cause oil problems, it's braking/accelerating forces combined with cornering forces. In a Westfield, cornering forces emulate braking/accelerating forces that are normally found on a bike, 'cos in car, the engine is mounted north/south, whereas on a bike the engine is transversly mounted, IYSWIM.............Centrufugal (or is it centripetal?) forces exerted on a bike during cornering will keep the oil in the sump (and, therefore the pick up immersed in oil, keeping the pump supplied..etc, etc), as the forces acting on the engine are all towards the ground, but along the axis that is in line with the angle of lean of the bike (if these forces weren't present, the rider would have to hang on, rather than be able to hang off.......). I'm not sure of the orientation of the 'Busa in an XTR2, but I'd still dry sump it because you won't be generating the centrifugal forces the engine's oil system is designed to cope with (even if it's transversely mounted, which I suspect it is) because it won't be leaning into the bends like the bike it came out of.

[Ian Gratton]

Blatman,

that is exactly correct - the XTR² has the busa engine mounted in the same orientation as the bike - transverse - it still uses the chain from the bikes gearbox pully which goes to a sprocket on the LSD (not to fear - the car has chain tensioners mounted on the rear bulkhead).

I think the sump is designed to cope with the rider laying the bike down into corners - and I guess a bike can't generate the same amount of lateral g as a car can.