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[HiProfile]

Engine makes 15hp and I think 18 ft lbs of torque at 3600rpm. So with a turbo maybe 20hp? If I turbo it which I rightfully should!

Don't complicated that motor with a turbo just yet. If that's a gx390 clone, you can double the power with relatively minor work & money. Kart goers take the gx200 to 26hp up from 7hp. The gx390 was designed to put out >13HP for 1000 hours or more, so it will still last a long time if you don't go crazy with revs.

Some cheap upgrades are increasing compression and lift. If your block uses the fiber gasket, you can get a Honda head gasket made from MLS to bump compression. Higher ratio rockers increase lift for almost nothing, although some require different pushrods and a pushrod guide plate. Some of the biggest gains can be had from a larger carb like a Mikuni, a bigger cam (stock has nearly no overlap/duration/lift), and a stinger exhaust. If you ever open the motor up, get oversized rings & file the gap for less blow-by and more power. One of the best mods to safely gain RPM's is a billet flywheel, the stocker is limited to 4k while a billet f/w will let you rev to 7-8k safely.

[Xgenturbo]

Problem is I cannot be playing with RPM to make power. 3600RPM and that's it. The variable hydraulic pumps I'm using aren't rated for any more. If I need extra power, I'll need it down low and quick. Perhaps even a homemade supercharger could work?

[Ntrain2k]

Increased power with more RPM and gear reduction?

2:1 would double the effective torque.

[92CXyD]

Problem is I cannot be playing with RPM to make power. 3600RPM and that's it. The variable hydraulic pumps I'm using aren't rated for any more. If I need extra power, I'll need it down low and quick. Perhaps even a homemade supercharger could work?

Maybe one of those 500cc/rev I see on egay all the time, like RM500 roots style blower:
http://www.ebay.com/itm/AMR500-SUPERCHARGER-IN-WORKING-ORDER-/251616319591?pt=Motors_Car_Truck_Parts_Accessories&hash=item3a95805867&vxp=mtr

That S/C looks like the TX04 from OguraClutch, but not complete sure. 
Info: http://superchargersunlimited.com/specs.html

It looks like the TX04 in this chart:

Page of specs. look at the TX04:
http://www.oguraclutch.co.jp/e/product/supercharger/size.html

The Spec. on displacement, max revs, and such are here, again look at TX04
http://www.oguraclutch.co.jp/e/product/supercharger/type.html

How they work:

[Xgenturbo]

Motor and hydraulic pumps are in, belt tensioner fabricated and she's almost ready for a trial run. I had to make a slight modification to the pumps to move the case drains to the top of them. As you can see there is not a lot of room in there and I dont think that supercharger could fit. The front of the crank will be used to drive the generator. The left side of the engine(as seen in the pic, right side of tank) is about the only room I have, if i go the turbo route then the turbo will have to sit in the exhaust cover in the rear. Something like a sealed, self lubricating vortech would be ideal. Next big thing i want to get out of the way is the reservoir and control linkages.

[92CXyD]

That supercharger is a sealed runs off of a crank just like the vortech S/C

There is also the s/c used on Seadoo's they are like the vortech s/c. 

[Xgenturbo]

well then I guess I just got schooled. I dont know too much about superchargers other than they make V8's happy

But a sealed unit would be the way to go then provided its cheap. No need to mess around with oil pumps, lines, etc. Now the question is...How much more is it gonna make me broke? This is supposed to be a low budget setup. A tiny turbo would still be cheaper.

[highroller54]

Those seadoo s/c's are $$$

[Xgenturbo]

Yeah that wont work then. I want a cheap ass setup... if I even need one. Here is a silly question and I'll probably get burned bad for saying this, but what about those electric blowers! Yes the cheap ones on egay! If one was to take one of those worthless pieces of shit, remove the electric motor and make it shaft driven off a belt. Would there be any advantage with an engine this small? Would I see any boost? Maybe that is all I need.

[highroller54]

I wouldn't think so, you need a real turbo me thinks.

[HiProfile]

Smaller pulley + higher rpm = same pump speed

The vast majority use a 1" shaft which is very common. You should be able to get a smaller v-pulley w/1" shaft to fit w/o issue. They also make 6:1 and 2:1 reduction boxes, but need the matching crank. The 2:1 also has a wet clutch similar to what's on bikes.

[Xgenturbo]

Smaller pulley + higher rpm = same pump speed

The vast majority use a 1" shaft which is very common. You should be able to get a smaller v-pulley w/1" shaft to fit w/o issue. They also make 6:1 and 2:1 reduction boxes, but need the matching crank. The 2:1 also has a wet clutch similar to what's on bikes.

But I still dont see the point in all the extra revs. I get that it makes more top end power and I can reduce pulley size to make them spin at the rated RPM, but this engine is going to run close to wide open throttle the whole time the tank is out for a spin. So the more I rev the piss out of it the shorter the lifespan, not to mention all the extra heat it'll generate and all the extra fuel I burn. 3600RPM is the factory default like the rest of those engines. They do this for reliability I'm assuming. I think that is a safe number for continuous use. A turbo would just allow the engine to stay up in that range once the pumps and generator start putting a load on it...Hopefully I wont even NEED a turbo. If it runs fine without then why fuck with it other than for the cool factor 

[DSharp]

Keep in mind, you're not going to be able to just bolt a turbo on.  You might be able to put a bigger carb on before the turbo, or get a fuel pump and hook up a boost line to the carb bowl.  Just putting boost to a regular gravity fed carb will result in some very lean afrs 

[Joseph Davis]

Why do I not own this?

[92CXyD]

Why do I not own this?

Should give him a free tune if he comes down to your neck of the woods. 

[Joseph Davis]

A free fucking knife between the ribs for stealing my tank and posting a build thread of it on my forum.

[Xgenturbo]

Why do I not own this?

They're not hard to build. Just takes a lot of time and money being pissed away. The end result may or may not be worth it, but it should be something along the lines of this:

https://www.youtube.com/watch?v=RLxlZ9hJVY4

As you can see its getting there. I still have a few bugs to work out. I may not need a turbo after all. She does about 1 hour to a tank of fuel or less if I'm on WOT all the time. I still need to make proper idlers for the rear and ditch the pneumatic wheels. I obviously need to finish the turret and all the details on the outside hull including front armor plate and rear engine cover. Right now I'm slowly plugging away on it as winter is around the corner and I'm up to my head in exams at school! Once Christmas break comes I'll have a lot more progress.

PS: Can I get OG status? I think I had 2000 or so posts back on the other site. I dont really care that much about the post count but I am an OG and would like the status.

[HiProfile]

But I still dont see the point in all the extra revs.

HP = Torque * RPM / 5252; If you can keep torque from dropping like a rock, then extra rev's mean more HP.

I'm not talking about spinning to 9k, even though GX200's can do so for an entire season, I'm saying 5-6k max. The way those constant-speed motors is the governor. If there is no load, the governor keeps the throttle open just enough to hold it at 3600 rpm. Adding a load causes RPM's to drop, so the governor open the throttle to compensate. The other benefit is when a huge load is put on the motor and rev's dip - going from 5k to 3k still keeps you in the power band whereas 3.6k to 2k means it will likely stall. As far as reliability, people seriously beat the crap out of the Honda clones for an entire carting season, and they are several pegs lower than true Honda's on every level. Just use decent oil and change it a bit more often than 6 months or 50 hours.

NA or S/C power in this situation will be more desirable. A turbo may not be able to respond fast enough, since it's possible it won't be pegged at full boost while free revving (no load). If you're lucky, you may be able to double the power with a "simple" turbo kit. A few mods (camshaft, carb, flywheel for safety) with a bit more RPM and you can more than double the power, which will also be instant-response power.

[jabberwock]

The hydro system will definitely help with long term durability when it comes to big singles grenading, which they generally do when pushed for a period of time.  I think a lot of that has to do with drivetrain shock. 

Valve springs, retarding the cam a tooth will push torque up.  I did this on a vanguard and noticed a lot of pull but I hit a new rev limiter.. valve float.  With springs or shims it could be pushed further.  I don't know how hydro pumps would work ungoverned though or how you would control the throttle.  Seems like if you were to go for more rpms you would want adjustment in the governor.  I don't know what's available in that regard.. I always pull the shit off and run a cable throttle.

Honestly if you find you are low on power I would just find a bigger vtwin and leave it governed or worst case get another single and run one pump off each.

[HiProfile]

Just add spring pressure to the governer arm to raise RPM. Some motors even have multiple holes for spring adjustment, my guess is mostly to account for shitty spring Q.C. (non-Honda). You can also adjust some motors slightly by rotating the base location of the arm on the shaft, but that's tricky. You don't need throttle control on a hydrostatic drive.

FYI most Honda's valve float at an RPM that's higher than the safe limit of the cast flywheels.

[Xgenturbo]

Quick update. Everything works great and this is the result so far. I have to do a few upgrades on the wheels and suspension over the winter but so far everything is, as Borat would say, "Great Success!"



Interior



Engine bay



Playing around on the skid pad.
https://www.youtube.com/watch?v=F-MRwRb-doA

[weirtech]

sweet!  more!

[ratcityrex]

So bad ass!!!!

[Xgenturbo]

sweet!  more!

Unfortunately you'll have to wait a bit. With winter around the corner and -50C temps, there won't be too much progress day to day. But I'm working on it as much as I can. Goal is to have it complete with turret and gun by next fall.

[Ntrain2k]

sweet!  more!

Unfortunately you'll have to wait a bit. With winter around the corner and -50C temps, there won't be too much progress day to day. But I'm working on it as much as I can. Goal is to have it complete with turret and gun by next fall.

Rear loading potato cannon?

[Xgenturbo]

sweet!  more!

Unfortunately you'll have to wait a bit. With winter around the corner and -50C temps, there won't be too much progress day to day. But I'm working on it as much as I can. Goal is to have it complete with turret and gun by next fall.

Rear loading potato cannon?

Something like that except the potato part   

[highroller54]

Lol

[Xgenturbo]

The new toy came in finally, new jig built (I fucking love jigs) New suspension mods done and new wheels in progress! This coming weekend should be fun.









Ok so I'll keep this short for you nogs. Old suspension sucked ass! Moment was too close to the fulcrum and I had more sag than Hotrex's tits. This was due to the fact that the hydraulic conversion put on some extra weight, especially in the back. The new setup requires a lot more force to move the control arm because the spring actually compresses instead of compressing part way and then moving back with the control arm.
The old wheels were getting torn to shreds by the track. I first tried pneumatics when I designed the tank, those didn't last. I then went to the runflats you see in the vids. They were ok but still got pretty torn up and wouldn't last in the long run. So now I said fuck it and started making these. These will probably outlast the entire damn tank.

[crxvtec91]

Badass!

[Xgenturbo]

Building the wheels this week. Need to wait for more hubs to finish the other six. The new plasma machine works like a champ, I would recommend it to anyone. Hopefully the hubs come in before next weekend and I have 12 wheels done and mounted on the tank in two weeks. I still need to clean all the wheels up and sandblast them. I didn't realize how time consuming this was going to be until I started.