What next for performance...?

[SDB]

1998 Gen 1 with UFO full race stainless exhaust, Stage 7 complete K&N filters, Double D clutch mod, frame brace, R1 brakes/stainless lines etc...

In terms of adding power, what is the next step that has the most "bang-for-the-buck"?

Cylinder head work (porting/pilishing/larger valves?)

Cams?

Displacement (big bore kit)?

Nitrous oxide kit?

Supercharger/turbocharger

I am used to fast cars with nitrous and used to have a nitrous refill station in my garage so I am leaning toward a 40 shot. I have a line on bottle and gauge for reasonable already (Pic). Just wanted to know what the logical next step is after the basic bolt on stuff.

I know changing wheel/tires size and gearing can have a significant impact. This bike will be 95% street with occasional passes yearly at the track. I plan to go to the track a bit as is before I consider throwing more power to it.

 

[sdt354]

Hard to beat Nos for bang for the buck. After that, displacement. IMO. Neither prolonging engine life. A well tuned stock engine with a full exhaust is fast enough for myself. Cams, porting, will add power, but at an expensive rate of return.

 

[Woody]

Convert to chain drive.
It will allow you to change gearing.

 

[one2dmax]

As mentioned the quickest way to power though to me it's always a pain is the nitrous. Having to take and refill the bottles sucks. The Superchargers work well to add at least a little power and I can still get those kits ($4500). There are no commercially made turbo kits yet. The cams/porting isn't worth doing unless you are also going increased displacement and pistons. The big bores will make good power increases too and never run out of spray. OR you can build them for boost/spray and get even more.

 

[Butch Cassidy]

... sell it. use the money for a down payment on a gen 2.

 

[02GF74]

There is no substitute for cubic inches".

 

[huw s]

The gen 1 vmax doesn't lend itself to easy tuning. If you look at any engine in general, the things to look at are the head, cams, carbs, turbo, supercharger, nitrous?
Well, I've looked at the heads, and while they look like a few days on the flowbench and die grinder could improve them, unless the bore and gasket size is increased, the inlet valves are about as big as they will get. Ditto the exhausts, since they are a tad close to the inlets. So yes, looks like some to be gained here.
Cams - don't see why these couldn't be reground within reason, but ideally for real power improvements you'd need to make some blanks ie pricey!
Carbs - the Japanese sorted this with the linked ports - fuel,injection has been discussed in another thread, and would yield top end, with potential low and mid range with 3d ignition.
Turbo - where would you put it? The v configuration makes it difficult without unequal length runners.
Supercharging - is this a road bike mod?
Nitrous - again is this a road bike mod? I guess it could be..
Lastly, exhausts. I have no idea why the standard downpipes are so small - does anyone make larger ones?
Oh, missed one, more ccs. Obvious really, 10% increase gives corresponding increase in torque. Do this with big valves, big exhaust tubes, new cams, EFI, and the vmax would be s beast and a half. But how much would it all cost? If you're a clever diy tuner probably several thousand...

 

[SDB]

I may have a chance to get a royal star Venture wrecked.... Motor would vive me more displacement and as I understand I would swap over heads/cam?

 

[one2dmax]

The RS bikes have lower compression and there are other issues that would not let it be an ideal donor for the motor. Piston/Valve clearance won't just let you swap on Vmax heads/cams. Side Covers are enough different that the waterpump would require a custom billet elbow to get it all connected well. BUT, you could put 86-93 Pistons in it and then the Vmax heads/cams along with working the cooling issues and have a good motor (I have one for sale by the way).
OR
Get an 86-93 Venture 1300. Put the Vmax heads/cams on it. And get an approx 10% HP increase.

 

[Fire-medic]

The RS bikes have lower compression and there are other issues that would not let it be an ideal donor for the motor. Piston/Valve clearance won't just let you swap on Vmax heads/cams. Side Covers are enough different that the waterpump would require a custom billet elbow to get it all connected well. BUT, you could put 86-93 Pistons in it and then the Vmax heads/cams along with working the cooling issues and have a good motor (I have one for sale by the way).
OR
Get an 86-93 Venture 1300. Put the Vmax heads/cams on it. And get an approx 10% HP increase.

Sean has mentioned about this before and this is a great way to proceed. That era Venture usually sells for little $ and the use they got is usually highway miles, which 'seasons' the block/cases, making it a good choice. One thing I suggest checking is the area of the block where the thrust bearing is, if it's worn, it can be fixed, but it's not an inexpensive one. You probably would be better-off finding another donor engine/cases. Check the crankshaft too for wear/clearances. In other words, you could take a chance, and just use the engine w/o a case-split, but if you want it to-live, and especially if you're planning to do anything-else, it's mandatory for long-life. 'Cheap-out,' by not-splitting the cases, and don't whine when it lets-loose.

 

[Vmaxstreetfighter]

I've had Nitrous on my Gen 1 and Gen 2 and it's a hoot. I wanted a bit of a boost but without splitting the engine so a bolt on nitrous kit seemed to do the job. I chose the Wizard of NOS Streetblaster 75 as the best and most reliable system. It was an interesting project - fascinating learning about the technology but I have to admit I hesitated slightly before pressing the button for the first time.

It wasn't quite as dramatic as I'd expected as the extra power made the clutch slip on the Gen 1. Once I'd had an extra friction plate added, it held OK and it gave a good kick in the pants when I hit wide open throttle. A micro switch on the carbs activated the system of 8 injectors (4 fuel, 4 nitrous) for pretty much instant power. The engine was 20 years old so I kept it at 50bhp. The bottle refills are a bit of a pain (15 british pounds for 20 oz of liquid nitrous) but the system is always a good talking point when parking up.

In 2017, the guy who bought the Gen 1 wanted me to remove it so I put it onto my Gen 2 instead. Ironically I had to detune it to 40bhp. I'm sure the 1700 engine can take more pressure but the constraint appeared to be the fuel injectors which I've heard are only good for about 240 rwhp. The Nash Flash & H pipe took the bike from 175 rwhp to 200 (actually 199.8 rwhp which really annoyed the dyno guy) so there was less to play with. I figured that a 40 shot into the airbox plus a PC5 fuel controller for the extra fuel management would be a much as the standard injectors could handle, with sufficient contingency. Again, I had to upgrade the clutch (double D) and air filter (K&N) and rear tyre (240 Avon) but it all works well.

I'd like more power but do not want to upgrade the injectors or mess with additional fuel injection so I'll leave it there. It does lift the insurance cost by £100-150 but that's OK. I haven't taken it to a track yet so it's just activated after traffic lights, between roundabouts and on dual carriageways. Apart from that I only ever use it when I want to go faster.

 

[cdgawatersports]

Does anyone know of a nitrous system for a gen 1 with no air box ?

 

[sdt354]

Does anyone know of a nitrous system for a gen 1 with no air box ?

Stage 7 ditches the air box. Then the install is straight fwd with available parts. A ready to bolt on kit specifically for a Vmax? I'm not aware of one.

 

[Traumahawk]

Does anyone know of a nitrous system for a gen 1 with no air box ?

Ive seen people that have put the spray into the intakes after the carbs.

 

[Vmaxstreetfighter]

Does anyone know of a nitrous system for a gen 1 with no air box ?

The WoN streetblaster injects into the manifolds. A blue and a red injector either side of the butterfly valves.

 

[one2dmax]

A few ways to go. I only have a few pics though had done a few others in the past (still help people out with welding up intakes to drill and tap out for the nozzles)

 

[SDB]

A few ways to go. I only have a few pics though had done a few others in the past (still help people out with welding up intakes to drill and tap out for the nozzles)

Which "hidden" style/kit do you think is best/easiest install for just a 40 shot on a bolt in full stage 7 gen 1 bike? How/where to install the nozzles? I ve been researching and see a couple different ways.. But would be interested in what achieves best distribution/atomization. If I did nitrous I would more than likely stay at 40hp and not do internal engine mods so wouldn't need a setup that could "grow"

 

[one2dmax]

There isn't a good way to hide the kit if you want it done right (in the intakes). Not enough room on the inboard side. You could custom make a plate setup like a car system but that is going to alter the carb spacing causing issues too.
40 shot is the max "safe" amount I would go with.
The intakes I show with welded up bosses are bout as ideal a location as you can get. This would commonly be called the "fogger" design.