Honda CX500 & GL500 Forum

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04-14-2008, 8:32 AM pampadori Joined on 12-15-2007 Roanoke, Va Posts 36 whos got the big turbo? anyone here running a upgraded turbo or larger injectors with higher boost?  just trying to see what people are doing to upgrade these rare little pups.    Report

04-14-2008, 9:56 AM Timothy_D Joined on 04-22-2006 Santa Rosa, CA Posts 686 Re: whos got the big turbo? No one is "upgrading" the turbos per se. The bike accepts about 19 lbs of boost.  Anymore sends it into failsafe mode, so a bigger bore turbo is a complete waste of time. There have been people who have polished ports, but no apparent performance gains have been determined. At this time, there are only three accepted as safe upgrades that actually enhance performance and reliability. 1) Boost Valves. 2) Blow off Valves. 3) Oil Coolers. As performance enhancers they are pretty negligible, but each one does add a solid reliability factor. If you want more performance, you really only have one answer: Nitrous.  Two '82 Turbos, GL650I, CX650C Why do I own four bikes? Because I'm not married. DUH!    Report

04-14-2008, 11:15 AM pampadori Joined on 12-15-2007 Roanoke, Va Posts 36 Re: whos got the big turbo? 19lbs of boost? really?  what one the ecm causes it to go into failsafe?  map sensor or pressure sensor or something?  i would think a Megasquirt system with a t25 turbo and maybe 370cc injectors, upgraded mls headgaskets you could get a healthy 100whp.  If the rods are up to it.  and at a much lower boost too.   who made the turbo that honda used and are there any compressor maps out there? I'm just researching, and bench racing.  thanks! Shaun    Report

04-14-2008, 11:50 AM Anonymous Re: whos got the big turbo? Honda overengineered these bikes, and as a result, these 25 year old machines are still pretty reliable for their age, and the technology involved. The ECU trips the failsafe mode immediately on overboost, and there are a multitude of sensors, which look for a multitude of conditions to prevent overboost.  To date, no one has cracked the turbo's MAP code. Incidentally, the 500T runs 19 lbs of boost, and has 82 hosrepower.  The 650T runs about 16 lbs, and runs 97 horsepower. People have been talking about re-engineering these machines, and so far no one has been able to do it, outside of my previously mentioned parameters.  You might want to look up Turbo Tim in the UK.  He's big into racing these bikes, perhaps he could help you.

04-14-2008, 8:10 PM George in Indiana Joined on 03-03-2006 Posts 317 Re: whos got the big turbo? 650 is already putting out 100 HP. Adding a resistor to the pressure switch to fool the ecu into thinking the boost is lower would work, however it's also going to give false readings throughout the entire rpm/boost range. Unlike adding a turbo kit to a modern bike, the CXT ecu is designed to work with the turbo, it knows it's there and it adjusts the fuel delivery accordingly. Plus if you trick it into thinking it's at 19 psi when you're really at 24, how long will it take to go into meltdown from a lean condition? I know the 500's roms were dumped and the file was out there ages ago but it seems to have disappeared. Maybe today with romulators something could be done with the code? After examining the insides of my defective 650 ecu, I believe there may be optional maps in memory that can be selected by simply adding jumpers. Too bad there's no way in hell I'm going to experiment with my good ecus. As you mentioned the megasquirt can probably be adapted and it's been talked about quite a bit. Several years ago a guy who wrote a book on fuel injection was working on a modified cxt fuel system but he dropped off the face of the earth. Anyone remember his name? He had a 500T and Silverwing. CX500 TURBO CX650 TURBO '86 Honda Elite 150 Deluxe '04 GSX1300R Hayabusa    Report

04-14-2008, 11:36 PM Anonymous Re: whos got the big turbo? Oh no, not again...oh well, at least this guy isn't using a beat up Volvo as an example of what he can accomplish when monkeying with the CXT's inner workings. Just a few random thoughts.....To make the bike perform significantly better, the power output would  have to be increased by significantly more than 50%. If what you are looking for is acceleration or top speed, why screw up a classic when newer bikes can be sacrificed, and get much more power because they are already making over 160 HP to begin with, before they bolt on the blower?. Another  question is that, given that there are no spare bikes left for the experiment, what are we really trying to accomplish here?.... it isn't a good idea revving the engine over 9000 RPMs, increasing the engine's displacement by altering stock parts isn't going to give much.... As most people know, drag increases with the square of the velocity, so going significantly faster than they do now will require gobs more HP.... just where the heck is this major improvement in performance going to come from, given the platform being used to start with?..... people seem to forget that we are talking about working with an engine that is less than 700 ccs.  Chances are, given the extensive experimentation necessary to make this work, if at all it can be done, would cost  bundles more than already existing mods for current hyper bikes and would end up wasting another rare bike.  What's the point ? J.T.

04-15-2008, 6:16 AM CXTURBOBOOST Joined on 05-03-2007 Posts 97 Re: whos got the big turbo? George--Do you mean Adam Wade? To mr.Big Turbo-- Forget it.. Really If that bike doesn't run well enough stock (in my opinion) there is something wrong with you. If the 500 isn't enough, buy a 650T. As already stated--These are very limited production bikes that were way ahead of their time. Many people have claimed they were going to "hack" the computer. Yet----No one has succeeded. It does exactly what it was designed to do. Another easy mod is to take off the muffler caps and cut out the inner baffle. It lets the bike flow better and accelerate faster. Just my .02 Pete    Report

04-16-2008, 4:09 PM squigbobble Joined on 04-10-2007 Yorkshire Posts 111 Re: whos got the big turbo? My 2p (even though I'm not a turbo owner) is why not upgrade the turbo in a different way? Instead of trying to overboost the engine and launch your cylinder heads why not swap the turbo for a modern one that's designed to give the same boost but has a lighter spindle so you get less lag and possibly a wider 'on boost' rev range. '83 CX500 Eurosport - distributed around my cellar. '98 Bandit 600 - still a bit rough. Dodgy squealing from engine... Fan & flywheel puller kits, £3 + postage    Report

04-16-2008, 4:30 PM rodent Joined on 10-24-2007 Derry NH Posts 214 Re: whos got the big turbo? Why not try and do a achohol (sp?) spray set up like they do on the Grand National's and Turbocoupes and I guess I have to mention all the little rice cars running around town. It will cool the charge allowing the engine to run cooler thus prodcing more horsepower. It will also add some extra fuel to help prevent the previously mentioned lean condition. My Turbocoupe had a Garret t3 turbo a iveco intercooler a rick gillis boost control valve and a spray setup and I was running 26# on a car setup for 15# I went from 205 horse to 323 horse with these few upgrades. 78 cx500 (rodent)(my twisted twin) 82 cx500c (parts) 86 cmx450 (wifey's) and in the future who knows http://s218.photobucket.com/albums/cc275/rodentcx/CX500/    Report

04-16-2008, 5:02 PM pampadori Joined on 12-15-2007 Roanoke, Va Posts 36 Re: whos got the big turbo? One thing that most people don't understand is you can make more power at the same boost depending on efficiency.  example... i had a t25 on a nissan 2.0L.  i ran it at 17psi and made 280whp.  i Installed a larger turbo and larger injectors and tuned it.  no other mods.  I ran it at 15psi and made 380whp.  2psi less and 100whp more.  At 25psi and with new cams i was at 450whp on 93 octane fuel. i'm surprised there isn't a few 200hp cx650's on this forum.  whenever a oem has made something turbo from the factory, there has been a guy somewhere with horrible economic sense make triple the horses as what his machine did off the showroom floor.  2000hp Buick GN's, 1000hp nissan 4 cyl's, 500hp 'busas.  again this is just bench racing, and i don't really have any plans to do it.  but these are the mods i would do if i had any money at all and a cx... GT25 garrett turbo with internal wastegate. megasquirt efi system 440cc injectors with homemade fuel rail. (enough fuel for 200whp on a 2 cyl engine) walbro 255lph fuel pump custom Cometic multi layer steel headgasket ( you can get them to make it for you by sending a stock one.) i'd keep the bore stock, but use skirt coated forged pistons. arp bolts. custom rods, or something aftermarket that would fit. custom cam with more lift, and a bit more duration. (misconception that too much duration on a turbo engine will let the boost just go right out the exhaust.  yes on the extremes but look at turbo vtec hondas making 600hp on the high cam.) 10 inches of pipe after the turbo for an exhaust (back pressure after the turbo keeps spool down.) then i would start to break stuff in the transmission. :0) just a pipe dream of mine.     Report

04-16-2008, 5:44 PM CXTURBOBOOST Joined on 05-03-2007 Posts 97 Re: whos got the big turbo? Good Luck..... The "turbo" being bigger? Are you referring to the compressor housing, turbine housing, or the whole turbocharger? The injectors will already flow more fuel than needed if you so ask them to do. If wishes were horses then dreamers would ride Pete    Report

04-16-2008, 5:45 PM Don in Oz Joined on 03-10-2006 Melbourne, Australia Posts 304 Re: whos got the big turbo? Pampadori,   Before you waste any more time "pipe-dreaming", go and visit someone who can show you a CX Turbo with its fairing off.   Have a look at the space/volume that's NOT available on this bike to do some/any of the mods you're thinking of.  Start thinking in terms of where you would put your mods, and also start thinking of how you would get any fabricator interested in a 26 year-old bike's modifications. Honda did a very good aerodynamic job with the fairing - if you dont use it (keeping all your mods INSIDE the fairing), then a lot of your dreamed-of power increase will get swallowed up by air-drag.    Report

04-16-2008, 8:01 PM pampadori Joined on 12-15-2007 Roanoke, Va Posts 36 Re: whos got the big turbo?  CXTURBOBOOST wrote: Good Luck..... The "turbo" being bigger? Are you referring to the compressor housing, turbine housing, or the whole turbocharger? The injectors will already flow more fuel than needed if you so ask them to do. If wishes were horses then dreamers would ride Pete i was referring to the whole turbocharger including manifold.  what size injectors are on the 500 and 650 respectively? and does anyone know of a fellow named Tim Boutle that claimed to have the fastest CX turbo?  what did he have done to it? i'm full of questions aren't I!    Report

04-16-2008, 8:59 PM Timothy_D Joined on 04-22-2006 Santa Rosa, CA Posts 686 Re: whos got the big turbo? Turbo Tim did it with one of the modifications that I mentioned above. Nitrous. The bike has so much torque that he had to add weight to the front end to keep it on the pavement. Seems kind of counter productive to me, but who am I to question? Two '82 Turbos, GL650I, CX650C Why do I own four bikes? Because I'm not married. DUH!    Report

04-16-2008, 10:35 PM George in Indiana Joined on 03-03-2006 Posts 317 Re: whos got the big turbo? Pete, Adam Wade sounds right, haven't seen him on any forums in a long time. There was also someone else building an intercooler and he disappeared too. Pampadori, On the subject of someone somewhere building a 200 hp 650T...how many CX650T bikes have you seen out on the road in the past 25 years?   Besides the 500T and 650T that I own, I've never seen another in person.  I don't think you realize how rare the CXTs are (especially the 650).  Most likely the average CXT owner just isn't willing to take the risk of destroying a bike that took years to find.  Those still on the road are usually in pristine condition...to me it would be the equivalent of taking an all factory original, low miles mint condition 63 split window Vette and modifying it. Someone at one time did the math and came up with 566 legitimate (non school bike) 650Ts being released.  Now factor in all the bikes that were wrecked or left to rot after stator failure during the past 25 years.  How many of these are still left on the road?  Only a few show up each year on ebay and it's usually the same ones bouncing around from one owner to another. I do admit I'm impressed with what guys have done to the GPz750 but there were a lot more of those bikes produced and they share many dirt common parts with standard Kawasakis. And here's what's packed under the fairing of a 500T...right side is even more impressive. CX500 TURBO CX650 TURBO '86 Honda Elite 150 Deluxe '04 GSX1300R Hayabusa    Report

04-16-2008, 11:31 PM Anonymous Re: whos got the big turbo? Dan's estimate was that there probably were less than a hundred 650s still on the road in the US. J.T.

04-17-2008, 5:15 AM CXTURBOBOOST Joined on 05-03-2007 Posts 97 Re: whos got the big turbo? I personally believe that estimate to be low. If you keep track of e-bay, quite a few have been sold in the last five years. Pete    Report

04-17-2008, 6:35 AM Anonymous Re: whos got the big turbo? Pete, when he said that to me, he was meaning the number of 650s that were actively being ridden ("on the road"), not the number of intact bikes in the US. My understanding is that there are quite a few that are in collections, some in museums like the ones at Bob Logue's dealership near the Amish rally site, or other less formal collections of someone who has twenty or thirty special bikes that they have decided to hold on to, but do not ride. Some of the bikes sold on EBay seem to have come from collectors that are starting to sell off their collections, but have not been actively riding them. A bike that I went to Maryland to look at last summer was the same bike that had been sold a few months earlier in the Pittsburgh area.... unfortunately it had been dropped, on both sides, no less, but was otherwise in pretty good shape.....he wanted waaay too much for it. Some of these bikes are being bought and then resold when people discover that they aren't exactly what they had been looking for. My post was to add to George's post about not having seen another 650. I don't have any experience to go by other than the response I get when I show up at a Honda dealership and people want to come out and look at the bike because they have heard of them and have either never seen one, or for the old timers, haven't seen one in 20 years. These are people who are in the business, not the average Joe rider on the street who doesn't even know they exist. My experience has been that it is a relatively rare bike. I don't watch EBay as carefully as I used to, but  I have seen maybe a half dozen of them being sold each year..... maybe I have missed a lot of them. I don't hang out with the TMIOA crowd, so I don't have that perspective as to numbers. Certainly there seem to be nowhere near as many as CBXs, which are of about the same vintage. J.T.

04-17-2008, 7:06 AM Anonymous Re: whos got the big turbo? Don, I may be wrong, but from what I gather from his posts, he seems to be merely interested in maxxing the horsepower, not putting together a reliable, rideable bike. Who knows, maybe after a half a dozen good runs at the drag strip and having blown the motor, then simply moving on to the next experiment or item of curiosity. J.T.

04-17-2008, 7:48 AM pampadori Joined on 12-15-2007 Roanoke, Va Posts 36 Re: whos got the big turbo? no i'm not that interested in following thru and building anything.  If i happen to find a cx500T motor at a salvage yard, i'd pick it up and put in in my custom and tinker with it.  but i'm not really going to ever find or purchase a cx turbo complete bike.  Its amazing the difference in the cx500 and the turbo model in terms of price and availability.  complete other ends of the spectrum. How cool would my custom be with a turbo motor transplant?  (i'll use the search button for that one)    Report

04-17-2008, 4:40 PM CXTURBOBOOST Joined on 05-03-2007 Posts 97 Re: whos got the big turbo? J.T. I understand your view. My personal view is this: One of these days these bikes will sky rocket in price. There are only so many and with Honda not making parts, they are becoming fewer and fewer. In 20yrs you might have a gold mine... You also might just have $20.00 worht of scrap? Hard to say. As far as price difference--dah---One is a fuel injected turbocharged model... Enough said.    Report

04-17-2008, 6:04 PM Timothy_D