Home Brew Tuned Exhaust/Spark Plug Guard

[Chief409]

I put the GPS on the buggy today, and after getting it set up I ran a top speed of 30.4 MPH. I think that's pretty good for a stock HY rolling 5T Trenchers. And my home brew tuned exhaust. Could be better though, the engine kept cutting out as it hit peak RPM. Need to figure out what's happening, but I have a couple ideas. I have some driver POV GoPro video I'll put up later after it's downloaded and edited.


Question: Anyone know if the spark plug guard for a Baja 5B will fit on the Dune Runner. I need to replace the spark plug wire because the ribs on the stock guard cut the H@@@ out of the plug cap. Also DDM has some 5B guards that are relieved so you can pull the plug without taking the guard off the roll cage.

 

[BertR]

Hey Chief... if you have a different fuel filter you can swap with the clunck filter in the tank that would be where i would start. I had that issue and it was a cloged fuel filter! Take the delivery line off the carb and blow in it. If its hard to pass air through it its cloged and starving the motor of fuel

 

[Chief409]

Hey Chief... if you have a different fuel filter you can swap with the clunck filter in the tank that would be where i would start. I had that issue and it was a cloged fuel filter! Take the delivery line off the carb and blow in it. If its hard to pass air through it its cloged and starving the motor of fuel

Thanks Bert, I'll check the filter tomorrow.

I posted a video in the Photo topic. Not fancy, it's all new to me. Dune Runner Herky Jerky.

 

[rcgasser]

The spark plug gaurd will not fit it will be too short the D/R is wider then the 5B I tried the same thing.

 

[Chief409]

The spark plug gaurd will not fit it will be too short the D/R is wider then the 5B I tried the same thing.

Afraid of that. Out with the Dremerl and time for surgery.

 

[Chief409]

I checked the fuel cap vent, it's OK. Ordered a couple of clunk filters. When I set up the home brew exhaust this thing was crazy fast, and runs through a tank of gas much faster. Not long afterward this cutting out problem cropped up. I'm not running real lean and never have, between brown and tan colored spark plug, so it isn't that. Must of sucked all the crap out of the tank, though I'm careful to keep the dirt out while filling up, there is stuff in gas station tanks.

 

[andyken]

My XB stock motor with 31/29 gears, tl100 tires, 990 carb and jet pro rear pipe ...I got 36.4 mph.

Didn't get a chance to measure the 29/31 ratio...I think it's closer to 40mph.

 

[Chief409]

I don't recall seeing any MPH numbers for a V3 4X4 Dune Runner, GitmoJoe was trying with a radar gun but ran into problems. It would be interesting to compare notes on; stock, mod engine, different exhaust, tires, etc.

I'm sure mine will beat 30.4 MPH as soon as the high RPM cut off is fixed.

 

[Chief409]

Have a couple of clunk filters that should arrive tomorrow, and ordered the Snappy Ultimate Fuel Line Kit. So, I shouldn't have to worry about the vent in the cap any more. Plus, I get a nice Billet cap. Not bad for $20. Provided, the kit fits on a Red Cat tank.

 

[Chief409]

Replaced the clunk filter, it was plugged, put in the tank vent kit and cleaned out the top of the carb today. Letting the Loctite cure overnight, tomorrow I'll see what the top end is.

I think Team Chase had a filter for the vent at the back top of the carb, but I can't find it anywhere. I was surprised at the amount of gunk I found.

 

[BertR]

http://www.davesmotors.com/s.nl/c.885035/n.1/it.A/id.7003/.f This what you need Chief?

 

[Chief409]

http://www.davesmotors.com/s.nl/c.885035/n.1/it.A/id.7003/.f This what you need Chief?

That's it Bret. Spent a couple hours looking for it, including at DDM. Don't know how I missed it. It's on order. THANK YOU!

 

[BertR]

Any time Chief!! I thought about getting one for my carb at one piont but was not sure how well it works ...now I have a inside scoop on it lol.

 

[Chief409]

When I took the top off the carb and saw grains of sand on the diaphragm and all the passageways in the plastic plugged I remembered seeing the video about it on the Fast Eddy site.

 

[Chief409]

Since the DR is down until I get the parts to fix the front suspension and replace all the wheel bearings, I'm putting in the OBR Prostock 30.5 this weekend. The stock HY has been through enough tanks of gas. AND, the OBR Race Ported 2 Bolt 30.5 Upgrade Kit arrived today, the Fast Eddy Ceramic bearings are here and I ran across the deal of the day at Harbor Freight Tools, a 1 ton arbor press for $39.99. I won't have a problem pressing the bearings into the crankcase. So, I'll be running and building the next hot engine at the same time!

Almost forgot. I now have a Traxxas sensor kit to monitor the cylinder temp and battery voltage which is displayed on a iPad mounted on the TQi transmitter. It came in just before Christmas. The sensor kit was out of stock for months so I didn't have one to install on the DR when I got it, but I have them installed on my Slash 4X4 SCT monster build and a T-MAXX I spent enough money on to build from a runner to a REAL BAD truck to buy a 5ive, and it is very accurate when checked against a IR temp gauge and my Fluke DVM. It will be on the Prostock and all future builds.

Reuse when possible and MAX MOD!

NOTHING on four wheels (or six) is stock around here.

 

[Chief409]

Just got an update on the suspension parts shipment, UPS says 2/04, next Monday. Since I don't normally get a chance to run during the week, I'll get a chance to run over my birthday weekend.

The evaluation of the Homebrew Tuned Exhaust progresses.

 

[rampagemt]

Re: Home Brew Tuned Exhaust/Spark Plug Guard

Looking forward to it. Glad your parts are in and almost here. Good luck and keep

us updated

 

[Chief409]

When I was running on the track the other day, the right silicon pipe came off at the end of the second tank. Big decrease in low end power right away. Most of the exhaust goes thru the left pipe, the slight flow reduction with the right pipe seems to set a resonant chamber in conjunction with the X-Can, thick X-Port and the left pipe. Someday I'll get this on a engine dyno and run with and without pipes.

 

[Chief409]

Tuesday I'll pick up the Victory pipe. Then I'll do some run comparisons. The Victory is tuned for a full race mod. Currently I have a build which will work with X-Can exhaust and the 8" extensions. Not full mod. So, I really don't expect much difference.

Now, with the stroker engine, there might be a difference.

 

[Sprint 77]

I think once you go to the Victory pipe. Your high end cut out issue will be cured. 2 stroke actually rely on the exhaust as part of the combustion chamber cycle. Less restriction and daisies box exhaust designs are very poor in high end efficiency. The combustion chamber relies on a poperly tuned pipe to return unburned fuel back into the cylinder. This is achieved by sound waves . Which is figured by math and conical shapes for the rpm range your wanting to run the most at. Home brew pipes without going through the math design and poorly MIG welded pipes that have wire trash and loose weld beads inside the pipe can destroy a motor in a hurry. I hope this helps explain your problem .