Author Topic: Looking for 4-stroke power (flame on) (Read 9341 times)

wilkin250r · « **on:** February 20, 2014, 02:36:31 PM »

Go ahead, insult me all you want.

I like to build complete engine combinations. Engine, carb, pipe, the works, and if I pull it off the bike it all stays together.

So my newest project is a mild-mannered trail machine. I'm thinking stock cylinder, probably stock porting, 36mm carb, complete intake with snorkel and all, but I can't decide on a pipe.

The goal here is NOT horspower. It's a smooth, easy, mild power delivery (yeah, like one of them slow 4-strokes). I don't want to improve low-end torque with a big-bore kit because it will have too much peak horsepower. This is a trail machine, slow and easy. I'm basically trying to turn my 250r into a 400EX.

What pipe? If FMF made the Gnarly pipe for the 250r, that would be my choice, I think FMF pipes are great for stock porting.

rablack21 · « **Reply #1 on:** February 20, 2014, 02:41:33 PM »

Most people seem to like the all around power of the ESR TRX 5 pipe for your purpose. I haven't tried it myself, but I'm sure someone who has will chime in.

pinned250r · « **Reply #2 on:** February 20, 2014, 02:48:24 PM »

I do love my trx5, great all around power(it even gives me some solid low end with a drag port), i will have a better knowledge of how it runs on a mx port this summer(putting a trx5 on my wifes R). I did really enjoy the all around power i got out of her old fmf fatty through a turbine core II silencer.

wilkin250r · « **Reply #3 on:** February 20, 2014, 03:31:47 PM »

I've got a FMF Fatty, I think it's a great pipe for stock porting, but it's still a handful to ride in the terrain I'm riding in. That's why I want to pull some power off the top end, and put it on the low end.

I know back in the day, several companies put together racing packages aimed at GNCC and other types of racing that were technical and required low-end power rather than peak horsepower. But those were still racing packages, designed with the maximum horsepower possible with a certain power delivery. I'm actually not looking for maximum horsepower, so those engine packages wouldn't apply to me.

Cripes, am I looking for a stock pipe?

etccb · « **Reply #4 on:** February 20, 2014, 03:37:45 PM »

That's what I was going to say. It may be just what you are looking for. Stock pipe with an alum silencer.

troybilt · « **Reply #5 on:** February 20, 2014, 03:42:16 PM »

Quote from: etccb;26270

That's what I was going to say. It may be just what you are looking for. Stock pipe with an alum silencer.

That's what the old school XC/Blackwater guys ran....

Tbone07 · « **Reply #6 on:** February 20, 2014, 03:44:55 PM »

So no engine porting at all?

rablack21 · « **Reply #7 on:** February 20, 2014, 03:46:56 PM »

You might also consider a paul turner type 6 pipe. Alot of woods guys really like them as well.

Or you could go with a DG or Pro Circuit pipe, they never seemed much better than stock.

jcs003 · « **Reply #8 on:** February 20, 2014, 03:52:59 PM »

i run a +4 stroke, mild port, esr trx-6, 38 a/s, rad valve with 13:40 gearing and it pulls very low in the rpms. not much clutching through the tight trails, weaving through trees. in comparison i rode a kfx400 and it (my 250r) seemed to have more torque and i got the benefit of the free wheeling of a two stroke. the engine braking of a four stroke sucks.

john

pinned250r · « **Reply #9 on:** February 20, 2014, 03:54:08 PM »

Yeah then count the trx5 out lol. Let us know what you find!

etccb · « **Reply #10 on:** February 20, 2014, 04:09:14 PM »

like jcs said the trx6, now replaced by the trx7 is a good smooth lower end brother of the very popular trx5. A good pipe for this type of use.

Victork · « **Reply #11 on:** February 20, 2014, 04:20:21 PM »

I find the LRD team b pipe to be a fantastic woods pipe. Very good low end smooth power in my experience and ive had a team B on atleast 4 trxs and a atc(wish i still had the atc pipe!)

wilkin250r · « **Reply #12 on:** February 20, 2014, 04:36:36 PM »

The TRX-6 (now TRX-7) was my first thought, but I don't know how well it will do with the stock porting. That's why I asked the question, if anybody has any experience with low-end pipes. I have no experience with pipes like DG or Pro-Circuit, but I've never heard anything stellar from them.

I'm familiar with the different pipe numbers from ESR (6 is low end, 5 is all-around, 11 is extreme top end), where does the ESR MX pipe fit into their lineup?

etccb · « **Reply #13 on:** February 20, 2014, 04:48:09 PM »

The mx is a brother to the 9 the same way a 7 is to a 5. It will have a hit that you are not wanting. 5 and 7 are the smoother pair. You can see it in the rear section taper from the center to stinger.

rk88r · « **Reply #14 on:** February 20, 2014, 05:01:01 PM »

I used to have a pt 89 race, it had a smooth hit and decent grunt. I really like the trx 5 and wonder about the 7 for a spare/trail/yard bike.