Ti-Powercore Speed Muffler and Powerbomb.... not impressed

[stavendirtbike]

My 2008 rmz250 after I fully rebuilt it (crank, bearings, OEM piston), along with porting done by MX-Time and all new stainless valves now has 7 hours on the engine.

I always hated how easily the stock Titanium head-pipe dented. My original was dented severely after I was t-boned in a race, but it wasn't even a hard hit. A friend gave me his spare 07 head pipe. After a few races/rides, the front of the pipe was dented quite badly just from roost.

I wanted to get the most out of my head-porting so I shopped around for a good deal on an exhaust system. I read the fmf 4.1 with stock header is what's preferred on the 08. My buddy with the 07 has the 4.1 with megabomb, no headwork, and I really like how his performs.

I found a steal on a new FMF Speed Ti-Powercore and FMF powerbomb. The muffler is much lighter than stock. The headpipe is heavier since I went with stainless steel..... which as I said before, I don't like the titanium headpipes anyway since they dent so easy.

Fit/finish is awesome. The muffler comes with a spark arrestor but I removed it before installing the muffler, I race strictly supercross/motocross.

Also forgot to mention, my bike has a JD jet kit already installed, and performed great with the OEM setup.

Sound seems to be about same as stock at idle and lower revs. It really barks though at upper rpms.

I mainly ride/race at a tight supercross style track. The low-end power of the rmz works great for this riding but I was still in search of more upper power.

I noticed off the bat there isn't as much low-end grunt. Low end seems soft. Exhaust made a good amount of noise, but it just seemed flat everywhere. There is no popping or bogging so I don't sense a lean condition. Fuel screw is 1.5 turns out complimenting JD's recommendations.

Not very impressed with the performance of the setup. I'm going to try putting the spark arrestor back in, maybe mess with the fuel screw a bit. Might try removing the powerbomb and adding my oem header.

Fit/finish great, some good weight savings, but the performance is just not there.

[rmzrider151]

I've heard a few people keeping their stock muffler on with an aftermarket headpipe. It's more relevant with FMF exhaust.

If I were you I would of bought a full Pro Circuit system. Best system available for 07-09 rmz 250s!!!!

http://www.motocrossactionmag.com/Reviews/News/MXA-PRODUCT-TEST-Pro-Circuit-RMZ250-T4-GP-System-6563.aspx

[stavendirtbike]

I know the PC system had great reviews but the darn price is what kept me away. I guess you either spend a good chunk of change, and get a mediocore exhaust, or spend a HUGE chunk of change and get a good exhaust.

[rmzrider151]

I know the PC system had great reviews but the darn price is what kept me away. I guess you either spend a good chunk of change, and get a mediocore exhaust, or spend a HUGE chunk of change and get a good exhaust.

Yeah, whatever suits you.

Hey, how is that factory connection suspension? Did you just get a revalve? Was it worth it? Please tell me more. Thanks!

[92db]

Did you ride with the motor mods and the stock pipe first?

Powerbomb and Ti powercore setup should run better then stock everywhere.

[stavendirtbike]

Did you ride with the motor mods and the stock pipe first?

Powerbomb and Ti powercore setup should run better then stock everywhere.

Yes and it had more low end grunt it seemed. I'm going to test out on a more real MX track though. The track I usually ride at is tight supercross.

FC Works great. The biggest thing is bottoming resistance. Stock, IMO, is HORRIBLE when you are hitting big jumps, and I'm only 140 lbs in full gear.

Their support is great as well. When FC is at the track, they will work with you if you need sag adjustments or whatever. Great people to work with both on the phone and in person.

I'd like to try some RG3 clamps next with the different offset. 20mm I think? The RMZ turns pretty good as-is, but I'm sick of having to always re-adjust the bars during a small tip-over. Plus I hear even with the different offset which should make it turn more aggressive, it actually helps with headshake, which I seem to have issues with on the RMZ when going fast in straights.

[Kev250]

Noticed you had sent me a PM about the G2 throttle. I really like it, its made my bike seem a lot more responsive, easier to ride and my wrist isn't getting as sore. Next to a suspension re-valve (which I would say is essential on an 07-09) its probably my favourite mod. It does make 1st gear a bit snappy though, but your not in 1st on the track, well I'm not anyway. Easy to fit, just dremmel/grind the two tabs away in the housing.

On the exhaust, I looked at a magazine test when my 08 was new and from memory the best pipe for the 08-09's going by the dyno results, spread and rpm range wise was the yoshimura, but the HGS and Akrapovic systems had massive peak bhp but also had very strong spreads. The FMF wasn't a top performer (but obviously gained over stock) and neither was the Pro circuit (and thats what dungeys bike was running at the time which is probably why people bought them). I remember the Akrapovic one being something ridiculous like 3hp over stock at 7000rpm, and I've ridden that pipe and always wanted one since. I run a stainless steel Dep s7 pipe which is fine for me, but I always check ebay out for a yoshimura or akrapovic!

I've ridden a stock 08 with a flowed and ported head and it was a monster, I couldn't believe the improvement, that now has an akrapovic exhaust and I'm waiting for a go!

By the way, I suffered with headshake a little on mine, an easy fix is to nip up the headstock nut a bit tighter, its effectively doing what a steering damper does. Motocross Action talk about this.

[stavendirtbike]

Thanks a bunch for that info Kev250!