Author Topic: Honda TRX250R Exhaust Systems (Read 25736 times)

Goon250r · « **Reply #30 on:** September 24, 2013, 09:56:06 PM »

Quote from: taft372;12954

how do these pipes compare to esr's trx11 pipes?

If you take a motor built for bottom end mid range go with the led If you have a motor setup for mid-topend go for the trx 5centermount you can go with the esr 11 but that is more of a topend pipe say drag circle tt racing... Also the 5centermount can also be ran with any of the above combinations (few people will admit it).. Really the esr 5centerount is a pipe thats hard to beat unless you got Arlans midrange portwork....

ledperformance · « **Reply #31 on:** September 25, 2013, 02:42:09 PM »

The pipe is an important part of any engine combination. If you want the best results with an LED engine then use a LRD or LED pipe. The feed back I get from customers is if their combination is to pipey and lacks acceleration, than changing to our pipe usually improves performance.
Again I will say, it has been my experience that if you run a 330cc or bigger engine using a pipe designed for 250 / 300 cc engines (meaning small tailpipe) you are very likely to have piston problems. Of course if you are making 55 hp or less or if you are only wide open for a short time period you probably will be fine. But if you make good hp you will fail if the engine is wide open for long. There simply be to much exhaust temperature.

rsss396 · « **Reply #32 on:** September 25, 2013, 03:25:40 PM »

I agree with Arlan,
IMO a 330 is right on the line for a reliable setup with a 1" ID, the proper stinger size for a motor is dependent on use,size and HP of a engine

If you hold the throttle wide open for longer periods of time than you need a larger stinger (snowmobile motors run 1-2 sizes bigger than bikes)
If you have a larger engine size, you may need a larger stinger size & IMO a 330 is at the tipping point of going to a larger size.
If you have a engine that is making above average HP for its size than it will many times need a larger stinger

There are guys running 370's with 1" stingers but I will bet they are not making big HP numbers, otherwise they would be burning down.

Now you can make a motor run with too small of a stinger, but you have to retard the ignition,lower compression, run higher octane, run a richer fuel mixture and not hold it wide open for long lengths of time. But then if you are trying to go fast, those are not options.

Tbone07 · « **Reply #33 on:** September 26, 2013, 07:24:31 PM »

I want that exact 250B stamped pipe, but with a 1" stinger for my future 344

ledperformance · « **Reply #34 on:** September 26, 2013, 10:16:42 PM »

We have a 250B pipe with 1" tail pipe on e-bay right now. Have at it!
Plan to build more in about 2 weeks. We are building vintage MX bike pipes right now. We are building a 1980/81 Yamaha YZ 250 Pipes right now.
We have learned a lot about exhaust pipe design working on vintage MX bikes. Yamaha's from the early 80's have road race port timings. We are able to give the bikes narly midrange power with our pipe designs. We improve the low end as well and with the high exhaust port they shread on top. We have used this design technology to improve over ported ATV's as well.
It still amazes me what you can do with the correct exhaust pipe design!

05450r · « **Reply #35 on:** September 26, 2013, 10:29:32 PM »

I need to buy another motor just so I can order the pipe,silencer and intake!!!

troybilt · « **Reply #36 on:** September 27, 2013, 02:38:09 PM »

Quote from: ledperformance;13159

We have a 250B pipe with 1" tail pipe on e-bay right now. Have at it!
Plan to build more in about 2 weeks. We are building vintage MX bike pipes right now. We are building a 1980/81 Yamaha YZ 250 Pipes right now.
We have learned a lot about exhaust pipe design working on vintage MX bikes. Yamaha's from the early 80's have road race port timings. We are able to give the bikes narly midrange power with our pipe designs. We improve the low end as well and with the high exhaust port they shread on top. We have used this design technology to improve over ported ATV's as well.
It still amazes me what you can do with the correct exhaust pipe design!

I should have contacted you awhile ago to help me with my MX Saber motor project. It had a drag port in it that I tried to tame with my own pipe I designed/made. I had some success but the consensus on here and the other sites was the ports needed welding. 200 exh port timing.

troybilt · « **Reply #37 on:** September 27, 2013, 02:44:00 PM »

Pics of my project I abandoned... 496 Saber MX

Arlen have you built any midrange small bore Saber's? Resleeved or welded ports?

Goon250r · « **Reply #38 on:** September 27, 2013, 03:06:22 PM »

now that Is sexy Beast right there...... Straight Monster I bet It pulled like a freight train. Where you get the nerfs/heelguards....

troybilt · « **Reply #39 on:** September 27, 2013, 03:29:54 PM »

Quote from: Goon250r;13208

now that Is sexy Beast right there...... Straight Monster I bet It pulled like a freight train. Where you get the nerfs/heelguards....

It pulled like a freight train alright... LOL! yes it was a beast, too much as it was for what I wanted to do. I had a hard time just getting it to run right, air leak issues. There was a thread that was 100 pages long on both the other sites with all my trials and tribulations with this project. I've since moved on, but when Arlen mentioned the pipes he was doing for the older vintage yz's with the road race porting, got me thinking again and would love to hear Arlen's thoughts on the saber.

I can tell you once you ride a saber everything else feels pale in comparison. My next 250r will be either a puma or saber. Right now I'm riding on the hybrid train with a yz450 laeger hybrid.... or if SRA ever builds some billet CR500 CB bottoms, I might give that a shot.

ledperformance · « **Reply #40 on:** September 27, 2013, 03:55:25 PM »

I have not. I just did a pipe for a 1980 YZ 125. It had 200' exhaust and 136' transfers. With our pipe and porting it now has perfect MX power.
I think a pipe could be built to repair your engine. The base can also be cut to lower the ports.
You might be surprised how well it works with our 456G pipe. That would be a lot cheaper than designing a pipe just for that engine.

ledperformance · « **Reply #41 on:** September 27, 2013, 03:58:36 PM »

If you really want to fix the engine I suggest we sleeve it. Sleeving is a great way to correct port timing and angle problems.

troybilt · « **Reply #42 on:** September 27, 2013, 04:24:13 PM »

Quote from: ledperformance;13216

If you really want to fix the engine I suggest we sleeve it. Sleeving is a great way to correct port timing and angle problems.

I bailed on the project and currently selling/sold the motor, I spend a ton of money and 3 years on the cylinder/bike project to have the base of the cylinder machined off to lower the port timing. It still was too much port timin and it was going to cost another $1000-2000 to resleeve it, re-port and re-nikasil. I decided to cut my losses and move on, and let the duner/drag guys enjoy the motor. I was curious to hear your thoughts on the saber, thanks for sharing. I designed a pipe with ~1200mm tuned length to try and tame it, it did a fair job of it, but there was still alot of issues with the motor as far as mx/midrange output. It really wants a big lectron and/or alcohol to run well. The Arctic Cat reed cage is a monster that I was trying to feed with a 40.5 A/S carb.

bnau267 · « **Reply #43 on:** October 14, 2013, 11:37:14 PM »

SRA CR500 bottoms....what's the story on these? Sounds wicked.

Redrider9982 · « **Reply #44 on:** May 18, 2014, 05:22:39 AM »

Not shure is this will work its my new LED 350G pipe mounted but my phones actin weird not uploading