TRX 2 - The tuned 850 one!
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- Mincehead
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Re: TRX 2 - The tuned 850 one!
You`re VERY lucky to find dyno time so cheap mate, over here it`s fuckin extortionate at some places!
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Re: TRX 2 - The tuned 850 one!
funnily enough I have a mate who has one... lucky me.
and I fix his computers for him, so dyno time is free. its not a load cell one though.
so you recommend ditching the TPS then?
and I fix his computers for him, so dyno time is free. its not a load cell one though.
so you recommend ditching the TPS then?
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Re: TRX 2 - The tuned 850 one!
No, keep the TPS.
Just disable it while you set your 10 point WOT ignition curve.
Don't be surprised if you still find your peak horsepower is reached around 7500-8000rpm purely due to the nature of the kent cams.
This will allow you to utilise 2 of the ignition points in the higher rpm range further down in the 3,000 to 6000 rpm range which will be in the region where the cams and exhaust system choice will have their most impact.
Your torque will peak maybe a couple of 100rpm either side of 6500 so good chance you can work with 6000rpm as your 8th ignition point, between peak torque and peak HP your 9th and the last point at 10,000. The limiter kicks in pretty good on the IGNITECH ( your choice on setting that one) and if your still around 10.5-11:1 compression 35* will more than likely be around your peak advance in the upper RPM range.
But as I mentioned, when you do the first 3 runs, std curve , -2 and + 2 advance, this will give you an idea on where to go plus how your fueling looks.
Easiest way to get the -2 and +2 retard/advance is to use the correction for cylinder 1,2 on the bottom of your map.
Just remember -2 on the correction is actually +2 advance because your telling the ignition unit white lies about the timing mark of 10btdc on the rotor.
Manipulation here will give you the same looking ignition curve persay but with a -2 or +2 over the whole ignition curve.
Your lucky too having a friend with a dyno.
Once you get an idea on your ( no TPS) 10 point curve, I'll give you a head start on how to get a starting point with your 100point TPS advances but the dynojet dyno isn't the best to sort this out,
It's better fine tuned on the fly at a trackday.
I've opted for a bit of a conservative 100point TPS %'s to factor in fuel blends/ summer winter conditions. I really couldn't be arsed tinkering on the winter vs summer day with this my main jets have more of an impact there.
But in saying that 100point differs considerably over the Std percentages due to the nature of CV vs FCR carbies.
Just disable it while you set your 10 point WOT ignition curve.
Don't be surprised if you still find your peak horsepower is reached around 7500-8000rpm purely due to the nature of the kent cams.
This will allow you to utilise 2 of the ignition points in the higher rpm range further down in the 3,000 to 6000 rpm range which will be in the region where the cams and exhaust system choice will have their most impact.
Your torque will peak maybe a couple of 100rpm either side of 6500 so good chance you can work with 6000rpm as your 8th ignition point, between peak torque and peak HP your 9th and the last point at 10,000. The limiter kicks in pretty good on the IGNITECH ( your choice on setting that one) and if your still around 10.5-11:1 compression 35* will more than likely be around your peak advance in the upper RPM range.
But as I mentioned, when you do the first 3 runs, std curve , -2 and + 2 advance, this will give you an idea on where to go plus how your fueling looks.
Easiest way to get the -2 and +2 retard/advance is to use the correction for cylinder 1,2 on the bottom of your map.
Just remember -2 on the correction is actually +2 advance because your telling the ignition unit white lies about the timing mark of 10btdc on the rotor.
Manipulation here will give you the same looking ignition curve persay but with a -2 or +2 over the whole ignition curve.
Your lucky too having a friend with a dyno.
Once you get an idea on your ( no TPS) 10 point curve, I'll give you a head start on how to get a starting point with your 100point TPS advances but the dynojet dyno isn't the best to sort this out,
It's better fine tuned on the fly at a trackday.
I've opted for a bit of a conservative 100point TPS %'s to factor in fuel blends/ summer winter conditions. I really couldn't be arsed tinkering on the winter vs summer day with this my main jets have more of an impact there.
But in saying that 100point differs considerably over the Std percentages due to the nature of CV vs FCR carbies.
laughter is the best medicine
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Re: TRX 2 - The tuned 850 one!
what spec is your motor cobba?
cant you just send me your map
cant you just send me your map
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Re: TRX 2 - The tuned 850 one!
12.5:1 comp, larger valves and flowed head, asymmetric cams 3* less than Over/V2 cams but with more lift and different air intake providing a positive pressure at speed.
As I mentioned if the compression is 10.5-11:1 you may not have to varie too much from the Std curve. The main gains will be in the TPS % settings.
You'll easily rob yourself across the board of 4-5 HP power using my map.
As I mentioned if the compression is 10.5-11:1 you may not have to varie too much from the Std curve. The main gains will be in the TPS % settings.
You'll easily rob yourself across the board of 4-5 HP power using my map.
Last edited by cobbadiggabuddyblooo on Thu Apr 06, 2017 6:59 am, edited 1 time in total.
laughter is the best medicine
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Re: TRX 2 - The tuned 850 one!
I honestly have not got a clue what compression this engine is. I have no data at all on it.
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Re: TRX 2 - The tuned 850 one!
FCR Users.
Where do you get your carb to airbox adapters?
We ordered some but at 40mm they were way too long
Where do you get your carb to airbox adapters?
We ordered some but at 40mm they were way too long
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Re: TRX 2 - The tuned 850 one!
Removed the airbox and use foam filters on mine.
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Re: TRX 2 - The tuned 850 one!
I thought they work much better with an airbox?
don't you end up with petrol everywhere?
don't you end up with petrol everywhere?
- dixonj
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Re: TRX 2 - The tuned 850 one!
Think you picked the Mz up from Paul in Carlisle.coxylaad wrote:Nope I think you definitely have me confused with someone else - neither my dad nor I have ever owned an Mz Skorpion!Mincehead wrote:I visited years ago, to pick up something destined to go into a skip.
An MuZ Skorpion sport, minus the XTZ660 motor.
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Re: TRX 2 - The tuned 850 one!
Was dyno'd with these filters on and no airbox and runs very sweetly. Don't know if this is the 'correct' way but I've never had any issues with them.
- Killerwhale
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Re: TRX 2 - The tuned 850 one!
I run stainless velocity stacks and no filter, runs really sweet exept when small birds gets sucked in and spat out....bubbaad wrote:Was dyno'd with these filters on and no airbox and runs very sweetly. Don't know if this is the 'correct' way but I've never had any issues with them.
- Mincehead
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Re: TRX 2 - The tuned 850 one!
AH YES!!!!!!!!! That`s right, Alzheimers R us.dixonj wrote:Think you picked the Mz up from Paul in Carlisle.coxylaad wrote:Nope I think you definitely have me confused with someone else - neither my dad nor I have ever owned an Mz Skorpion!Mincehead wrote:I visited years ago, to pick up something destined to go into a skip.
An MuZ Skorpion sport, minus the XTZ660 motor.
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Re: TRX 2 - The tuned 850 one!
doyou get any issues with fuel vapour getting everywhere under there?Killerwhale wrote:I run stainless velocity stacks and no filter, runs really sweet exept when small birds gets sucked in and spat out....bubbaad wrote:Was dyno'd with these filters on and no airbox and runs very sweetly. Don't know if this is the 'correct' way but I've never had any issues with them.
- dandywarhol
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Re: TRX 2 - The tuned 850 one!
I recall the first time I met Mincehead with his FCR with pod filters - it was stinking of fuel from being blown back into the filters when the inlet valve snaps shut. IMO individual filters are fine for circuit riding at wide throttle but twins benefit from an airbox at lower revs when the blownback fuel can be drawn into the other cylinder and not wasted to atmosphere
1996 TRX 850, blue, Ohlins 46HRCLS, Race Tech Gold Valves, 0.90 springs, Venom pipes, R6 brakes............
1974 Yamaha RD250A, Candy Blue
1998 Yamaha SZR660, blue of course
1967 Yamaha TD1C 250, Blue and white
1974 Yamaha RD250A, Candy Blue
1998 Yamaha SZR660, blue of course
1967 Yamaha TD1C 250, Blue and white