Wanted - More Power

[TRiXy]

Ooops... Wrong section. Would a moderator please be kind enough to move this to the correct section?


Just got my bike back from a Major, and rather expensive service half expecting that they might be able to breathe abit more life into my poor ol' bike by means of proper adjustment on the bits that matter, However I was rather dissappointed to find that there's no appreciable difference in power in any part of the rev range... So... I'm hanging out for some easy power, She's already got a set of Yoshi pipes on it, but other wise is totally standard. And parts, or advice on how to extract a few extra ponies (without handing over the entire contents of my hip pocket) would be hugely appreciated.

Thanks in advance.

[Jak]

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Here?

[slow codger]

The free way is to make sure tyres are correct pressure and that chain is in good condition and oiled. Then it starts to cost money!!

Dave E

[Killerwhale]

Ooops... Wrong section. Would a moderator please be kind enough to move this to the correct section?


Just got my bike back from a Major, and rather expensive service half expecting that they might be able to breathe abit more life into my poor ol' bike by means of proper adjustment on the bits that matter, However I was rather dissappointed to find that there's no appreciable difference in power in any part of the rev range... So... I'm hanging out for some easy power, She's already got a set of Yoshi pipes on it, but other wise is totally standard. And parts, or advice on how to extract a few extra ponies (without handing over the entire contents of my hip pocket) would be hugely appreciated.

Thanks in advance.

Skimming the head to up the compression is quite cheap, around 40-60£ over here. New gasket of cource....
Should result in some more grunt but i don´t know if i would bother if you don´t like the TRX....just buy a bike with more power. If you DO like the TRX then spend!!

[phuk72]

A proper service (new fluids, filters, valave clearances) and, as has been said, correct adjustment of chain and tyre pressures is the first bit.

TPS mod will fully advance the timing and is worth some free power. Have a search on here for how to do it. You'll also find my dyno charts which show the mod is worth between 1 & 2 bhp through the rev range (on my tuned engine).

Thereafafter, you are into money.

When you say Yoshi pipes, are you talking after market headers or just end cans. Any tuning will be restricted by the standard downpipes. So that would be my first port of call. Only prpblem being that yopu will not see much in gains frm that alone - perhaps 2 or 3 bhp.

Flatslide carbs (FCR 41s are the best) are the most effecttive pound for bhp bolt on. You can expect anything up to 10bhp if you have a free flowing exhaust - probably nearer 7 if you use standard downpipes. Expect that to cost you anywhere between £350 (if you can get the second hand) to £600 if buying new.

After that, I'd go for a big bore kit. £350 for the kit plus rebore, gaskets, oil and time

Then gas flowed, skimmed and ported head. Approx £200 plus gaskets and time.

All of the above should net you about 100 bhp (I've done all of the above btw).

After that, you are into serious money for small gains. Crank lightening, lighter rods, knife edging etc etc.

[HansJ]

...
You'll also find my dyno charts which show the mod is worth between 1 & 2 bhp through the rev range (on my tuned engine).
...

Nope, your charts only show MPH range...
Hint hint



Otherwise, what he said is correct! Best bang for the buck is a set of FCRs, everyone should consider that before spending money on cans in my opinion...

[idl1975]

The easiest, cheapest, sure-fire way to a more powerful bike is usually to sell the current bike and buy a faster one. For the same money as the TRX, you should be able to get an old 600 with a bit more power. Mid-90s ZX-6R , CBR6 F2 or F3, or even a final-year FZR600. Add a few hundred AUS$ and you can have your choice of bikes with at least another 30hp.

There isn't really anything cheap you can do to make a noticeable difference, IMO. FCRs are the best bang for the buck and deliver great induction noise, but they're only "cheap" in comparison to the other options. As you've no doubt discovered by reading the forum and doing some research, there's no serious overbore (that works - 29cc would appear to be your lot) available for the 850, and you can't get many more revs if you plan on the engine lasting very long (IIRC because the head won't oil properly much above the existing redline).

You could try making an ally fuel tank at home, home-brew a 2-1 exhaust (like at least one person on here...) or finding some beat-up lightweight race wheels and figuring out how to adapt them. Saving some weight would be worth a few ponies.

Only other things to do which might make a noticeable difference (if you did get 2bhp extra, I suggest you probably wouldn't notice) - (1) if not done already, get the bike set up by a pro on a dyno so that the a/f ratio can be optimised across the board; (2) gear it down a tooth at the front or 2-3 at the back.

Ooops... Wrong section. Would a moderator please be kind enough to move this to the correct section?


Just got my bike back from a Major, and rather expensive service half expecting that they might be able to breathe abit more life into my poor ol' bike by means of proper adjustment on the bits that matter, However I was rather dissappointed to find that there's no appreciable difference in power in any part of the rev range... So... I'm hanging out for some easy power, She's already got a set of Yoshi pipes on it, but other wise is totally standard. And parts, or advice on how to extract a few extra ponies (without handing over the entire contents of my hip pocket) would be hugely appreciated.

Thanks in advance.

[phuk72]

...
You'll also find my dyno charts which show the mod is worth between 1 & 2 bhp through the rev range (on my tuned engine).
...

Nope, your charts only show MPH range...
Hint hint



Otherwise, what he said is correct! Best bang for the buck is a set of FCRs, everyone should consider that before spending money on cans in my opinion...

I think you'll find they do (a nice comparison between CV carbs and FCRs with and without TPS mod)

http://trx850.motomaniac.net/forum/view ... s+vs#p6157

Still can't find the AF charts you want though

[HansJ]

...
You'll also find my dyno charts which show the mod is worth between 1 & 2 bhp through the rev range (on my tuned engine).
...

Nope, your charts only show MPH range...
Hint hint



Otherwise, what he said is correct! Best bang for the buck is a set of FCRs, everyone should consider that before spending money on cans in my opinion...

I think you'll find they do (a nice comparison between CV carbs and FCRs with and without TPS mod)

http://trx850.motomaniac.net/forum/view ... s+vs#p6157

Still can't find the AF charts you want though

?

Is yours revving to 15000?

I checked now, and it if I am not completely way off, it's MPH at the X-axis, with 2 gear changes? (But weird scale anyhow, 150 MPH?)

The charts I wnated to peek at don't have to have A/F, I was looking more for the look of the curves, at different RPMs. Reason is that the head job was intended to give more boost in mid-range, but it seems like I have more top in comparison with others. But I have not compared with a similar engine setup, and that's where you come in

[TRiXy]

Thanks for all the tips guys... The Yoshi pipes it's got are a full kit, with titanium down pipes, 2-1-2 setup... The TPS suggestion is one i've not heard before, Will definately look in to that. I guess the kinds of gains i was looking for were air box mods, pod filters? My understanding is that nice trumpets in an air box, will breathe better then simple air filter pods straight over the carbies. The FCR suggestion is another one i've looked at, but haven't been able to justify the price, but i'll look further into that one considering how much i just paid for a service that gave me nothing... As for whether or not i "Like" the TRX... I spent saturday morning last week walking around the bike shops, and there was NOTHING there that tickled my fancy and cost less then about AU$10,000 so i can easily justify a few quid to make it MORE enjoyable... I'm also not interested in going for a 600 sports bike, because i like the fact that the TRX doesn't break your wrists after a moderate ride. Does anyone have any opinions about dynojet kits or cams? I noticed they weren't mentioned at all... at this stage also, i'm not interested in doing machine work to the head/block, just bolt on power...


Thanks again for the advice.

[cobbadiggabuddyblooo]

Best bet as suggested go down one tooth on the front sprocket to start and you'll enjoy the more useable torque/power out and around about having fun and then go get a set of FCR's and you'll start coming out of the corners in second gear back wheel sliding and front wheel lifting WWWWOOOO HHHHOOOO....yer....

[phuk72]

I guess the kinds of gains i was looking for were air box mods, pod filters? My understanding is that nice trumpets in an air box, will breathe better then simple air filter pods straight over the carbies.

Does anyone have any opinions about dynojet kits or cams? I noticed they weren't mentioned at all... at this stage also, i'm not interested in doing machine work to the head/block, just bolt on power...

.

The standard air box is very restirctive and you can get more power by lifting the tank a touch (2 pence pice thickness spacers at the front of the tank does help). You could also cut holes in the airbox / remove the snorkel but I personally wouldn't go further than the snorkel.

proper jetting and set up on a dyno will reap rewards but dyno time is £40 an hour

Oh yeah - cams. Forgot about them. Got them too. I have Kent cams in min for midrange. alternatives are Vee Two (top end) and Tornado (dunno about them). My view is that they are not worth having without gas flowing / porting

[TRiXy]

Best bet as suggested go down one tooth on the front sprocket to start and you'll enjoy the more useable torque/power out and around about having fun and then go get a set of FCR's and you'll start coming out of the corners in second gear back wheel sliding and front wheel lifting WWWWOOOO HHHHOOOO....yer....

I've already got the gearing lowered a bit, I did it for the sake of riding with a pillion, but I was acctually planning on going back to standard gearing... it seemed to make better use of the torque rather then trying to make use of revs... just my perception i guess...

When i got the service done I enquired about dyno time, and they said a standard dyno tune is AU$400... + dyno jet kit if so desire.

[cobbadiggabuddyblooo]

Paid $330 for a dyno at springwood at the time running std carbs and staintunes. Found another 6 to 7 h/p by getting everything running right.

[idl1975]

I think the general consensus is that cams only work if you're properly gasflowing the head and (if it's power you're after) are prepared to sacrifice "ridability".

Don't disagree with you for not wanting a 600 or something more focused, but if you don't want to spend $$$, I can only suggest again that you try losing weight from the bike. If you have a Yosh full system, maybe sell the whole thing and buy an Akra 2-1 - that will save you quite a few kilos, which speaking roughly, is as good as a few HP at lower speeds. And as already suggested, try to snag some lightweight race wheels from e-bay, make up some spacers and run the traditional cheaptastic Sigma bicycle computer in place of your instruments. There's quite a bit of weight to be saved there.

Thanks for all the tips guys... The Yoshi pipes it's got are a full kit, with titanium down pipes, 2-1-2 setup... The TPS suggestion is one i've not heard before, Will definately look in to that. I guess the kinds of gains i was looking for were air box mods, pod filters? My understanding is that nice trumpets in an air box, will breathe better then simple air filter pods straight over the carbies. The FCR suggestion is another one i've looked at, but haven't been able to justify the price, but i'll look further into that one considering how much i just paid for a service that gave me nothing... As for whether or not i "Like" the TRX... I spent saturday morning last week walking around the bike shops, and there was NOTHING there that tickled my fancy and cost less then about AU$10,000 so i can easily justify a few quid to make it MORE enjoyable... I'm also not interested in going for a 600 sports bike, because i like the fact that the TRX doesn't break your wrists after a moderate ride. Does anyone have any opinions about dynojet kits or cams? I noticed they weren't mentioned at all... at this stage also, i'm not interested in doing machine work to the head/block, just bolt on power...


Thanks again for the advice.