Engine recommendations;

[O.J.Racing]

At present the thunderbolt II in the UK is supplied with a 23cc engine, as I intend to race the buggy at national level would this be sufficient or would the CY 26cc or even a 29cc be a better option for racing at this level.

[mradlin]

I think you'll have to go over thr rules in the races that your entering. I think they have a size limit. :confused:

[O.J.Racing]

I think you'll have to go over thr rules in the races that your entering. I think they have a size limit. :confused:

Copied from the rules as you can see a little confusing.LOL

There will be two vehicle classes, Standard class for 2 Wheel drive buggy’s up to 26cc and an 4 Wheel drive class for four wheel drive, We will still run monster trucks etc with motors up to 30cc and carry on trying to accommodate any cars that turn up.

[O.J.Racing]

After further reading the rules for the 4 wheel drive class are;

4 Wheel drive class
The four wheel drive, monster and outsized cars may use up to 30cc engines.
A maximum permitted size off 900mmx550mm.
Other restrictions will be relaxed.
Remember safety is paramount.
The Scrutineer's decision will be final.

[mradlin]

Sounds like almost any engine is game.

[O.J.Racing]

Sounds like almost any engine is game.

Yes looks that way.:surprise:

So what do people recommend is the 23cc strong enough for racing or should I look at a tuned stronger engine like the 26cc or 29cc.

I have read in threads about a tuned 28.5cc engine anyone have any info on this?

[RCKIWI]

I would check and see what other racers are running and go the same way

[Pipeous]

depends on what you need for power. if you look at say onb engines, their track tuned motors actually have smaller carbs so you get fuel economy and tames a little power band down. a smaller cc will rev higher, so take that into consideration. do you need torque or revs? a 26 or 27 is a good balance between the 2.

[mooman007uk]

Seeing as I'm running one I'd have to say the OBR 27.2 full mod 4bolt zen (I've run many ported 28.5 and now have OBR ported 30.5 in my ramp with VRC pro)...the 27.2 is Seans best motor and it's perfect in the nutech cos they're so light...you don't need the torque of the 30.5 and the 27.2 has more torque and revs than the 28.5 , it revs to 20K with the VRC propipe...you're looking at 7HP with insane revs...no one will even get close to you on the track if you run this motor with the VRC...and you can buy just the longblock to save cash and bolt the 23cc parts to it.
And it'll run great with good fuel economy as pipe mentioned with the cy's 668 carb

[Croozer]

Its seems to me that the 30.5 would do well in the TB in track racing with the 4 wheel drive, the extra torque could come in handy when exiting corners.

[mooman007uk]

my rampage is 13lb heavier and definitely needs the 30.5 but to be totally honest the TB being 24-25 lb would be better off with more revs...the 27.2 has more than enough low end boils my MT tires on a loose surface instantly...it doesn't need any more off the line torque
as it's unusable....i know merlin has a full mod 30.5 in his TB...it hooks up ok on grass but i'm interested to see how it does on a dirt track with the buggy wheels...gas jockey ran his MT with buggy wheels and stock 26 with boat pipe and drag racing him was just about neck and neck...i just lost traction and couldn't use the extra power...of course when the option gears are available then you'll be able to gear to the motor accordingly

[Croozer]

i'm interested to see how it does on a dirt track with the buggy wheels

Yes, that would definitely be the decision maker for me, I would love the torque coming out the corners on a track but if its spinning its a no go (literally).

[x Wild Bill x]

I am going with Moo and even though I don't have a Nutech, just looking at the specs that it is light you don't need monster torque. You want something that has good zip down low but will keep pulling up high into the rpms. Not only that, but the higher a motor can rev, the more versatile it will be with the same gears...

So, I would go with like a 27cc or so that can rev...

Just my .02

[Croozer]

If the 30.5 can take advantage of the TB's 4WD and hook up it would be a terror on a race track.

[Freeprawn]

The rules for the 4wd class in the UK are quite relaxed.

The max engine size is 30cc. Not a LSOR rule but a BRCA Insurance regulation. Basically your not covered by the BRCA insurance if your engine is any bigger than 30cc. (see page 25 of the 2010 BRCA Handbook for details)

Talking of the BRCA, you are best joining before you turn up to race, this is for insurance reasons rather than any other reason. It costs £15 a year. You might be able to join on the day but not sure. http://www.brca.org/

The hard core group of the racers have a forum too good place for asking questions, although they are mainly all into overpriced 2wd cars lol http://team5hite.forumup.com/

The only thing you will get pulled up for is any exposed exhaust pipes. The ones that have caused the most problems are the hpi baja ones. It's because marshalls were getting burnt fingers on them when they were picking the cars up.

In my opinion if you have never been racing before you would be best running a bog standard 26cc engine (maybe a tuned 26 if you are minted or have a good rate on your credit card lol) with a tin can standard exhaust and a standard clutch with an 8000rpm spring on it. If you really wanna get technical you can also lighten the standard clutch shoes quite a bit too.

It's the set up I won the 2008 season with my MCD money pit. I will using this set up this year hopefully not in an MCD though lol ;o)

You will find the car very predictable and not get into trouble going stupidly fast on long bumpy straights.

If you can drive for a 10 min heat without crashing then think about going faster ;o)

Come racing it's fun :)

Nige

[Croozer]

CC Racing Pro Mod makes big power and its 26cc.

[TMRperformance]

going by the type of rc you have and style racing you are doing you can choose many different engine choices. not going with a 30.5 leaves you with many choices such as: 22.5cc 23.3cc 24.1cc 25.4cc 26.3cc 26.9cc 27.2cc 27.9cc 28.8cc 28.5cc and 29.5cc

all of these if done right can make great power... all depends on the variables, car weight, track type, track size, terrain, tire size, gear ratio, pipe, etc... alot of people purchase what many others are using or what seems to be the hot seller, that does not mean that it will be the best engine for you.

[Merlin]

ONB 30.5 Full Mod :D I love mine, definately not to much at all, and ONB have this motor within 200rpms of the 27.2 so it screams like a raped ape. the instant punch when you hit the trigger is fantastic! I suspect as long as you go with a well known porter, you will not be disapointed either way :)

[nicolas]

I would check and see what other racers are running and go the same way
I agree with that...In France, we run with 26...But some have 26 stock, others 26 prepared, different exhaust pipes...you have to run for 30 mn :engine+pipe mustn't be too greedy...

[nicolas]

And Al is right ! it depends of many variables...and the way you drive..just a few drivers manage to run with my engine :rolleyes:

[O.J.Racing]

Thanks everyone some good info there and plenty to digest before making a final choice.

[O.J.Racing]

Nige,

My BRCA licence is all sorted as I have been racing nationals for many years in other scales however I am new to 5th scale so looking forward to the new season.

As I am new to large scale racing its just understanding what is the best direction to take with engines I think it will be possibly an oddified red head as they seem popular here in the UK. Therefore I will be able to get info and advice at most race meetings and Ian will be on hand if I need technical support at an event.

Thanks for the help.

O.J.Racing.

[Pipeous]

I have been reading Ian's comments on the rc tek forum for many years. he's brilliant

[mooman007uk]

+1 to that...Ian is a top notch guy...very personable and knows what he's doing...pretty damn good round a track too.
the nitrous system he built for Pete at pro5th was nuts...only system i've seen for an rc that has a fuel solenoid too so you can dump in heaps of nitrous and not lean the motor out

[Croozer]

I'm gonna try out a CC Racing Engines Pro Mod Zen (26cc) but I will toss it on my 5T and use a stock 26 with a pipe on the TB for track use.