question for cdi box gurus....

mopar1rules

mopar1rules

Active member
Joined
Jan 30, 2006
Messages
3,198
Age
40
Location
manitowoc, wisconsin
does anyone know at what rpm the power valves are programmed to open fully on a '01 srx? how about on a '02 viper? i'm wondering if yamaha has a different rpm programmed in each cdi box, for the fully open position time on the power valves, between '01 srx and '02 viper. anybody know? valin? BETHEVIPER?
 
Upon start up valves cycle open then shut,other wise they don't open till 6500 and above.
Click to expand...

not a guru but this is how daman explained it to me. myself I was woundering if they fly open or if its gradual opening starting from 6500.
 
i think rpm is the same but rumor has it that timing is way more advanced on a viper at 8500 rpm. maybee with a search can find more info, there has been alot of posts in the past on here before about cdi interchanging and so forth. always seems to be a hot topic, i know it was for me when i started using this site. i wonder if programmed high rpm boxs do anything diffrent with the opening rpm also. this is an interesting direction, i havnt seen anyone ask about the opening rpm since ive been on here.
 
i have the specs from valin on the '01 srx timing curve, and i know of the "hot" viper timing, but i would like to know at what rpms the valves start to open and are fully open, on the viper cdi/engine and the '01 srx cdi/engine.
 
JOSH, I HAVE THE RACE BOX FOR A 2000 THAT WAS ON HERE. I INSTALLED IT ON MY 2000 AND DEVELOPED A VERY BAD LOW END '' POP '' RIGHT OFF THROTTLE. MY WAY OF FIGUREING IT WAS A LEAN SPOT WAS THROWING CHOKE ON AND OFF FAST AND HOLESHOTING THIS SLED. IT THAN WOULD BE ALL BUT GONE. I THAN CHANGED MY NEEDLE POSITION. TOTALLY GONE, SLED SHOOTS TO 8500 AND HOLDS. THIS RACE BOX WANTED MORE FUEL ON BOTTOM, PROBLEY OPEN POWER VALVES UP WAY SOONER. NO DOUBT IT MADE A DEFFERENCE. I DON,T HINK THIS HELPS YA, BUT ITS WHAT I SAW. 3:16 (yammie tony)
 
YAMMIEGOD3:16 said:
JOSH, I HAVE THE RACE BOX FOR A 2000 THAT WAS ON HERE. I INSTALLED IT ON MY 2000 AND DEVELOPED A VERY BAD LOW END '' POP '' RIGHT OFF THROTTLE. MY WAY OF FIGUREING IT WAS A LEAN SPOT WAS THROWING CHOKE ON AND OFF FAST AND HOLESHOTING THIS SLED. IT THAN WOULD BE ALL BUT GONE. I THAN CHANGED MY NEEDLE POSITION. TOTALLY GONE, SLED SHOOTS TO 8500 AND HOLDS. THIS RACE BOX WANTED MORE FUEL ON BOTTOM, PROBLEY OPEN POWER VALVES UP WAY SOONER. NO DOUBT IT MADE A DEFFERENCE. I DON,T HINK THIS HELPS YA, BUT ITS WHAT I SAW. 3:16 (yammie tony)
Click to expand...

yeah tony, that timing curve was alot hotter on the bottom and mid for ya then. yeah, i'm trying to get ahold of the specs on the '01 srx box and the '02 viper box, of when the power valves are told to go to full open and when they start to open. i was thinking about putting a viper cdi on my srx and then just running the piped/ported viper jetting. i don't know why that wouldn't work. my exhaust port on my srx, now matches my exhaust port on my viper, so i'm thinking if the cdi's are programmed to open the valves at a different rpm, that i would be benificial to have the viper box w/valve opening time, on my srx, to go w/my slightly modded viper spec exhaust port. guys know what i mean and am trying to get at?? kinda confusing/hard for me to explain.
 
I POSTED TO YA I HAVE A STOCK 01 SRX BOX I,LL TRADE YA FOR THAT EXTRA VIPER BOX YOU HAVE. I WOULD LIKE TO TRY A VIPER BOX ON MY 02 SRX 3:16 (yammie tony)
 
the box is really my buddies. he's looking to sell only, or maybe trade for some helixs or weights. he has no use for the '01 srx box and i don't really want a spare. sorry tony.
 
TONY... if you were to use a Viper CDI box in your 2002 SRX would it have to be a 2004 unit with the DCS control built in or would it not matter??? Just curious!
 
mopar1rules said:
yeah tony, that timing curve was alot hotter on the bottom and mid for ya then. yeah, i'm trying to get ahold of the specs on the '01 srx box and the '02 viper box, of when the power valves are told to go to full open and when they start to open. i was thinking about putting a viper cdi on my srx and then just running the piped/ported viper jetting. i don't know why that wouldn't work. my exhaust port on my srx, now matches my exhaust port on my viper, so i'm thinking if the cdi's are programmed to open the valves at a different rpm, that i would be benificial to have the viper box w/valve opening time, on my srx, to go w/my slightly modded viper spec exhaust port. guys know what i mean and am trying to get at?? kinda confusing/hard for me to explain.
Click to expand...
mopar, not sure on the valve opening time but doesn't the viper box have like 8 deg more timing at 8500 than the srx box.thats alot,i thought that was why they spin the vipers with pipes a few hundred rpm faster to get them in a rpm where the timing has fallen off a vew degrees.be careful to much timing can do bad things.
 
I can tell you one thing.......Yamaha programmed all of the CDI's for the SRX's. There were others who were involved with the programming and design of the timing curve, but it was Yamaha who programmed all of them. I was told this by Yamaha's R&D department, and that the timing curves on the race CDI's were all the same, and those were the only boxes that they programmed. There is no such thing as differently programmed SRX race CDI's. Now, that being said, I only have timing specs for those boxes from 8000 RPM and up. I was told they were the same as the stock CDI until 8250 rpm, where the race CDI holds an even 11 degrees from that point on. I have posted the timing curves of both the SRX stock and race CDI's, and the Viper CDI's as well. A search will bring up that information. The moderators should make it a sticky.

As for the question regarding the exhaust valves..........I cannot tell you if they open sooner or later on the race CDI's, but I have watched the valves open and close on the dyno, and it appears that they simply open and close, and therefore appears as though it is not gradual.
 
ok, i'll try searching for the info on the viper cdi specs.

9801srx, i heard the same about the viper box having 8deg more timing, but i'm spinning my srx at 8700, cause that's where mine makes peak HP, w/current porting. if the viper engines (about same as srx engine), can survive w/8deg more timing, i don't see how i can't make my srx survive w/viper nozzles, viper needles, viper slides.....basically i'm going to start out w/piped/ported viper jetting. anybody know if a '02 viper cdi is "plug & play" on a '01 srx?
 
i would guess that with the porting to go with it you should be able to do it, i was thinking about trying the same thing to mine this summer. i thought that with porting close to a viper and the right jetting should be enough to stand the timing advance. mine is a 2000 though, i just got the harness and box for an 01, the harness not only inclused the dual controls for the warmers but i beleive is the same plug as vipers where the harness plugs into the box. from what i have been told so far is that 01 srx did not have dcs but the 02 did, not sure but was guessing that all vipers had dcs cause even the 02 vipers when you start them has that first seconds that you watch the tach spike before it starts working. i figured the timing and porting alone would be a gain, i knew nothing about if the valves open at diffrent times but would be another + if it is earlier. if u try it let me know how it comes out cause i was gonna wait till after season to try it, during our down time. good luck
 
You must log in or register to reply here.


Back
Top