Member Contributer Kingmdm Posted February 21, 2016 Member Contributer Share Posted February 21, 2016 I want to install a jet kit and a slip-on to boost the HP of my 97 VFR. Are there any particular ones that work best? Also, are there any other bolt-on engine mods that will increase power? Link to comment Share on other sites More sharing options...
Member Contributer Dutchy Posted February 21, 2016 Member Contributer Share Posted February 21, 2016 Hello King, If you get satisfaction from tinkering (like I do). go for it. But don't expect too much more HP. I see you have 3 so by all means, play! If your aim is quicker acceleration or top speed, playing with the sprockets can help. Advantage of an aftermarket muffler can be weight savings, the oem weighs 6.1 kilo, my Akrapovic 1.6...... If you do find the Holy Grail, do post up here please. Link to comment Share on other sites More sharing options...
Member Contributer JZH Posted February 21, 2016 Member Contributer Share Posted February 21, 2016 You can get a significant amount of extra oomph with a TTS big bore kit (837cc), but that involves a full engine rebuild, plus the cost of the new pistons, rings and head gaskets. I had TTS do my 3rd gen ten years ago, and it's still working well, but I can't say it's a necessary mod. Many other more modern bikes put out the same HP with no expensive modifications at all... Ciao, Link to comment Share on other sites More sharing options...
coupedupsubie Posted February 21, 2016 Share Posted February 21, 2016 I would add a K&N or other high flow air filter before jetting. Once the weather warms up in Maine I am putting my bike on a dyno to check horsepower and AFR. I am running a stock filter with a TBR header, left exit exhaust. It was jetted according to the previous owner. Link to comment Share on other sites More sharing options...
Member Contributer Kingmdm Posted February 21, 2016 Author Member Contributer Share Posted February 21, 2016 Great responses. Sprockets and a filter are an easy way to add some power. 100-105 rear wheel HP is my goal. And I would like to get my hands on that TBR left side header. Been surfing the web for one but no luck. Link to comment Share on other sites More sharing options...
coupedupsubie Posted February 21, 2016 Share Posted February 21, 2016 They are hard to find. Depending on how long I keep my 750 I may have a replica made out of stainless with a couple changes. Link to comment Share on other sites More sharing options...
Member Contributer Kingmdm Posted February 22, 2016 Author Member Contributer Share Posted February 22, 2016 What modifications would you make to the TBR header? Link to comment Share on other sites More sharing options...
coupedupsubie Posted February 22, 2016 Share Posted February 22, 2016 Changing from slip joints with springs to a v-band clamp and moving where the joints are for the rear headers. Link to comment Share on other sites More sharing options...
Member Contributer slowbird Posted February 24, 2016 Member Contributer Share Posted February 24, 2016 When I dyno'd my VFR, with the Aftermarket TBR Pipe (stock header) and stock airfilter and Carbs the AFR's were good. I imagine a better air filter still wouldn't warrant jetting. Link to comment Share on other sites More sharing options...
750 Posted February 24, 2016 Share Posted February 24, 2016 One sure fire way to increase performance on a 750 is to keep it in the garage and buy a 1200 instead :D But seriously though, so many people have tried to squeeze more out of this motor, Honda got it just right....it's great for what it is, plenty of go in my opinion. Best bet would be to shed weight. Swap the led subframe with aluminium, get a carbon fibre tank (they can be had) etc...you'll get it down to under 190kg and will be increasing the seat of pants dyno HP by 15-20bhp due to power to weight being so vastly improved. Link to comment Share on other sites More sharing options...
CandyRedRC46 Posted February 24, 2016 Share Posted February 24, 2016 Look into swapping the 34mm 4th gen carbs, to the 36mm 3rd gen carbs before you start messing with the jets on the factory carbs. I would imagine that this would trade a little lowend torque for some added top end hp. Link to comment Share on other sites More sharing options...
Member Contributer gll429 Posted February 24, 2016 Member Contributer Share Posted February 24, 2016 Look into swapping the 34mm 4th gen carbs, to the 36mm 3rd gen carbs before you start messing with the jets on the factory carbs. I would imagine that this would trade a little lowend torque for some added top end hp. nope! bigger doesn't always mean better. you think honda didnt already try this ?? besides the carb angle is different. that a hell of a a lot of playing !! new carb intake boots custom plenum to fit the airbox... all that work when you just change the jets for and needles for 100 or so bucks. Link to comment Share on other sites More sharing options...
CandyRedRC46 Posted February 24, 2016 Share Posted February 24, 2016 Honda did already try 36mm carbs, from 1990-1993... They were not trying to build a performance mod bike, they were transitioning from the 1986-89 sports bike to the 1990+ touring bike. I am sure that when they went to 34mm carbs in 1994-1997, they did it for more lowend throttle response at the expense of top end hp. Then Honda went back up to 36mm throttle bodies for the 1998+ VFR800's. Why would you need to do custom anything? Just find 3rd gen parts or a 3rd gen bike... Link to comment Share on other sites More sharing options...
coupedupsubie Posted February 25, 2016 Share Posted February 25, 2016 When I dyno'd my VFR, with the Aftermarket TBR Pipe (stock header) and stock airfilter and Carbs the AFR's were good. I imagine a better air filter still wouldn't warrant jetting. From my experience and what I have gathered from talking to a few other people an air filter tends to be the reason to rejet a bike over a basic slip on muffler. I don't recall if it had a muffler or not but my father has a cbr1100xx K&N kicking around because it made the bike run like crap and the jetting/sync costs were more than he was going to pay for the gain. Link to comment Share on other sites More sharing options...
Member Contributer Dutchy Posted February 25, 2016 Member Contributer Share Posted February 25, 2016 Free dyno run a lillte while back OEM air filter no rejet Akarapovic with db killer in vertical axis HP horizontal axis speed in kmh clickerdiclick http://vid113.photobucket.com/albums/n206/Dutchy_748/HPIM2493.mp4 Link to comment Share on other sites More sharing options...
coupedupsubie Posted February 25, 2016 Share Posted February 25, 2016 Free dyno run a lillte while back What gear? Atmospheric data? I just want something to compare to as I haven't seen many dyno sheets for the 750. Link to comment Share on other sites More sharing options...
CandyRedRC46 Posted February 25, 2016 Share Posted February 25, 2016 When I dyno'd my VFR, with the Aftermarket TBR Pipe (stock header) and stock airfilter and Carbs the AFR's were good. I imagine a better air filter still wouldn't warrant jetting. From my experience and what I have gathered from talking to a few other people an air filter tends to be the reason to rejet a bike over a basic slip on muffler. I don't recall if it had a muffler or not but my father has a cbr1100xx K&N kicking around because it made the bike run like crap and the jetting/sync costs were more than he was going to pay for the gain. Some air filters are designed as a drop in replacement and some are designed as a performance filter that may require fueling changes. A perfect example of this is the vfr800s, the kn and bmc are drop in filters that flow no more than the factory filter, while the pipercross was designed as an actual performance filter. Link to comment Share on other sites More sharing options...
Member Contributer Dutchy Posted February 25, 2016 Member Contributer Share Posted February 25, 2016 It was a free run at a dealer event. 1,5 meter below sea level Partly cloudy in a gear I have no idea really, sorry :-) No doubt there can be gains to be had, "better" is the enemy of "good" after all. For for me she is good enough....... Instead of more power, my advise (free) is to invest in better suspension and fuel to burn and ride her. Link to comment Share on other sites More sharing options...
douglasthecook Posted February 25, 2016 Share Posted February 25, 2016 I agree with Dutchy above, sort your suspension first, then upgrade your brake components. The stock suspension and brakes aren't bad, but can be easily overwhelmed if not properly serviced, and more hp/torque is added. Link to comment Share on other sites More sharing options...
CandyRedRC46 Posted February 25, 2016 Share Posted February 25, 2016 time for cbr front end Link to comment Share on other sites More sharing options...
Member Contributer Kingmdm Posted March 10, 2016 Author Member Contributer Share Posted March 10, 2016 Well, I've purchased a Viper race s/o, a Factory stage 1 jet kit and a Piper Cross air filter. The problem is that I really don't want to molest any of my three RC36's because they are all completely stock and in showroom condition. Spent hundreds of hours and $$$ to get them in that condition. At the same time, I want to experiment with some performance mods. I'm conflicted. Link to comment Share on other sites More sharing options...
Alhazred Posted March 10, 2016 Share Posted March 10, 2016 Factory pro used to do an ignition advance mod,I think it just involved sending them your flywheel and they modified it to 5 deg advance. I sent them an email and they don't seem to have any info on it other than they used to do it and don't any longer but it's something else to look into. Link to comment Share on other sites More sharing options...
TheStig Posted March 10, 2016 Share Posted March 10, 2016 Brakes, suspension, geometry improvements, better tyres & reduced weight will give performance advantages. Exhausts and if headers are changed - jet kits too, will give more smiles. Link to comment Share on other sites More sharing options...
RVFR Posted March 10, 2016 Share Posted March 10, 2016 Awe man, have I been down this road big time. like most have said Honda did good with this one. Going bigger carbs as noted doesn't work, been there, not worth it. Now jet kits are cool and all but there's a trick to em, been there as well, they need to be matched to the exhaust flow capacity and that is where it gets tricky, there's really nothing out there, there was, but that 20 years ago GL finding it. you could build one all the while dyno testing this and that. there also some sacrificing going on with mid torque and top end HP it's a bamboozling act at best. I did a lot of experimenting thinking sure there's an easy solution, there ain't, unless you want to open up the engine. My best happy medium was dialed in at 99hp with stock carbs K-N no piper cross then as I knew, Stain tune slip on. Believe it or not, just fine tuning the needles is all that's needed, and a lot of patience and a dyno, yes it's that touchy bottom line get air in and out as fast and efficient as possible. if you want fast acceleration, change the gear ratios, if you also want a well balanced machine that handles well there huge gains here, make sure you up grade the suspension, it's a great bike, it's just that Honda did pretty good with this one right out of the gate. Link to comment Share on other sites More sharing options...
TheStig Posted March 10, 2016 Share Posted March 10, 2016 A long time ago when there were Dyno jet kits for these bikes (About 20 years ago), I put a slip-on onto it and took it to Rino Dyno in London, to have a chap called Nick tune it on a Dyno. I think it made maybe 3-5 hp more than before, if that. It's still got the same jet kit fitted but a different high-level slip-on exhaust now. Backfires a tiny bit on the over-run every now and then, which isn't down to anything else than carbs. I've tried to tune out by enrichening the pilot jet settings but couldn't so I just live with it. It's so little I don't care any more.If Tyga makes the left exit exhaust for a high level silencer we'll have to see if there's any way to get jets to improve it again, as I guess there will be demand for such kits from the supplier that offers such a kit.. Time will tell. Link to comment Share on other sites More sharing options...
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