Vmax/Exciter SX PSI Twin Pipes

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ace16a

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Anyone have the spec sheets for the PSI twin pipes for a Vmax or Exciter SX with info on jetting the flatslide carbs? I have specs for the older roundslides but they don't give any info on the flatslides. Thanks
 
I am in the process of doing the same mods to a 1984 Vmax 540 and a 1993 Exciter SX. I installed PSI duals on both and am currently trying to get the jetting right. The Vmax looks like it will run well with 300-310 main jets, middle clip position on the neddles (I am running 1991 Exciter round slides on the Vmax). My 1993 Exciter SX has the stock carbs. Psi recommended 3 jet sizes larger. It is not working for me, ran ok in -30 but still rich from plug chops. I removed the oil pump and line and run 50:1 premix. I aquired info on pipe shoot outs for the SX, the PSI duals produce the most HP @ 8000 rpms. Stick to stock clutching, pink primary and stock secondary settings. Testing the psi duals states 150 main jet and 3rd clip position. I am at 152 and 3rd position and still rich. I am running EGT probes and the EGT's are low, 680 degree's max. I am in the process of ceramic coating and exhaust wrapping the pipes, that may require richer jetting so I will leave the 152's in there. 1 clip position on the needle = 0.5 jet size. I also installed a set of 1996 Vmax 600 flat slides on my 1991 Exciter with a Bender Racing single pipe (sounds bad ***). But have 156 in there, has a real bad bog on the bottom, needle position is the lowest (least fuel). Needle has a odd taper though, will try 150 MJ and maybe change the needles. Try 150 main and 3rd position but do plug chops. I rebuilt my Exciter engines and have 125 psi for compression.
 
84 Vmax 540

mod pipes on the vmax? I was going to put Aaen pipes on mine. I talked to tim benderwho told me that the stock pipes work better on the vmax.
 
Read the 1987 V-MAX Stock Evaluation and Pipe Test and the 1986 Update Porting articles on http://www.vintagevmax.com from DynoTech


Stock V- Max Stock Pipes
RPM CBT CBHP FUEL BSFC CAT
8000 57.0 86.8 56.7 0.67 74

Stock V- Max PSI Pipes
RPM CBT CBHP FUEL BSFC CAT
8750 52.1 86.8 58.3 0.69 78

Stock pipes with porting update
RPM CBT CBHP FUEL BSFC CAT
8250 57.2 89.9 65.1 0.77 86

We installed our PSI twin pipes on the update ported V-Max with the following results.
RPM CBT CBHP FUEL BSFC CAT
9000 52.3 89.6 52.4 0.63 87
 
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i have a 1987 exciter with stock 570 and i have twin pipes and the stock pipe i also have round slide mukuni and buttefly type carbs i dont know what the best setup should be ? any ideas out there ? are butterfly better than round slide and if so why is it better to use twin pipes or a single pipe any advice youd be valued thanks
a ditched my old doo far this basket case exciter and 2 of evrything
 
Which pipe for an 87 Exciter?

From Dynotech Pipe Shootout #14, The DRE single pipe made the most HP on a 1991 Exciter 2, 87.9HP @ 7750 rpm.

From Dynotech Pipe shootout #29 for the 1993 Exciter SX (keep in mind that the SX was modded from the factory) It has more HP stock. The PSI duals produced 103.6HP @ 8000 rpm. The Bender Racing single produced 100.6HP @ 7750 rpm. Considering that the duals weight twice as much as the single, you could add another HP for the extra 7 lbs (rule of thumb, 1 HP = 7lbs). I have limited time so far to get the jetting sorted. I found that I was not getting enough heat in the dual pipes so I ceramic coated them and exhaust wrapped them. The Flat slide carbs are the way to go but if you are going to do it, try and find a set of SX carbs. I have two sets of Vmax carbs but the jet needles and the nozzels are different, one set of slides are the same but you need to change a bunch of stuff. The Bender Racing single pipe sounds great, it is louder than the PSI duals, The Psi's sound good too! Looks like I gained alot of power but I never did run the sled with the factory pipe. I rebuilt the engine and put the Psi Duals on it. The single did wake the 1991 up though!
 

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bluepsylo- where did you find that info? I would also like to find more info on SX porting specs, so i could port mine the same or similar.
 
I ran my sled in 34 F weather with the following setup:
160 main jet
57.5 pilot jet
3rd clip position
I was waaaaaay rich. So rich that once the motor warmed up, it would bog down with very little throttle.

I changed to this setup
160 main jet
55 pilot jet
2nd clip position
Runs great, almost perfect, in 20 F weather.
 
1993 Exciter SX with dual PSI pipes and cold air kit.

Well guy's I finally have the jetting sorted out! I ride mainly between 2000 and 3000'.

152MJ
2nd clip position
55 pilot.

Now I am running a Dial A jet system with external snorkels. Here's the set up.

PSI dual pipes (running Digatron Dual pyrometer's) I keep my EGT's below 1300 F. Plugs are a nice rusty / card board brown.

Was running 3rd clip position but she was rich down low, bog off of idle.

-Cold air kit.
-AD Boivin skid.
-Vmax struts with Bender long travel kit.
-8" risers with 4" rise fat bar.
-Mountain max clutches with Bender / SLP helix compound helix's.
 
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