HMF vs. Sparks

[05DodgeDakota]

Trying to decide on a full exhaust for my build. I'll be running a stock pipe for now until funds allow. Should I get the HMF Competition Full system or the Curtis Sparks Big Core? Both are about the same in price.

[CJM]

Your not gonna be able to really take advantage of a full exhaust on these bikes due to the way the headers designed. Id rather run a slip on or if you really want a full exhaust run the HMF. The sparks is nice but VERY loud and imho the price aint worth it.

[Thumpin440ex]

Another vote here for HMF.. The Sparks is a nice kit, but imo the HMF is better quality, looks nicer.. And not going to be much if any difference in power felt

John

[05DodgeDakota]

Well either way I'm gonna use a quiet core. My engine builder recommends HMF, that's what they use on their race MX TRX450s. He also said that HMF actually manufactures alot of other companies pipes for them. But I know the Curtis Sparks is real popular on here and I hear it's the best for all out power.

[HondaPohl]

I wouldnt say that HMF is better quailty than the sparks. Sparks is very well built exhaust but like CJM said its very expensive and loud. If your on a buget go with the HMF slip.

[05DodgeDakota]

doing the full system, so price is about equal. I do like how the HMF COMP series has muilt sound inserts

[Baileygunns]

If you're squeezing every last bit of power (ie head work, piston, cam) and you're after that last little bit go with the Sparks... Otherwise, The HMF is fine... I think the new comp series is a super nice looking pipe and the inserts are great to have if you need to hush it up for noise restricted riding areas.. Close friend of Mine put an HMF comp on his KFX450 and it looked, sounded, and performed great...

I have a sparks on my Honda 450R... Love the power but it is a bit loud.

[05DodgeDakota]

anyone every try a sparks with a quiet core?

[Dewey DTP]

Sparks standard core is my choice. it makes brouder power than the HMF does and does not have a lean spike at 7000 rpm like the HMF does.



Dewey

[Thumpin440ex]

Originally posted by Dewey DTP
Sparks standard core is my choice. it makes brouder power than the HMF does and does not have a lean spike at 7000 rpm like the HMF does.



Dewey

Post this info or charts if you will... A exhaust will not all of the sudden lean spike on a like a hicup in a fuel or timing system..

John

[Rohr397]

I just got a Motoworks and I like it much better then anything else I've used and it only costs $209.95. They're obviously good too cause factory Can-Am. Anyways I love mine it makes my 400ex run like a 450 now, the power is way more spread out and usable, and there's a lot more of it too!

[Rohr397]

Here's the page (the first two pictures are what mine looks like): http://www.motoworks.com/catalog/product_info.php?cPath=21_60_26_45&products_id=28

And here's the dyno:
http://www.motoworks.com/05technical/img/Honda_TRX400EX_Slip-On.jpg

[Dewey DTP]

Originally posted by Thumpin440ex
Post this info or charts if you will... A exhaust will not all of the sudden lean spike on a like a hicup in a fuel or timing system..

John

i will get it off of my dyno and post it for you to see. i had a customer change from a HMF to Sparks pipe. every 400EX i have
ever seen goes lean just before peak HP then dips rich after peak HP. this can be timing you can change it with differant intakes also i like the stock intake boot.



Dewey

[Thumpin440ex]

I would like to see it.. I would be more so thinking it is a dyno/ afr tool issue then a actual problem with the exhaust.. If it leans up then goes back to normal would again be a fuel or timing issue.. I have seen many dynos that get hp or hard tq spikes.. are you using a actual afr 02 bung sensor or one in the end of the pipe??


John

[Dewey DTP]

here is the dyno of the two pipes with hp and air fuel
my afr works just fine.

Dewey

[Thumpin440ex]

Hmmm that is very interesting with that.. Any tq numbers? The HMf run ran a fatter jet and still leaned out more then the sparks.. Yet up top didn't make as much hp, was fatter.. I am not to sure how well the dyno is set up. They can surly be persuaded. I know this coming from a hot rod back round, still into this kinda stuff.. Just seems like a very od dyno to me.. If the hmf leaned out, it could be flowing that much better then the sparks kit.. I think it was a possible issue with the lean spike, it happens all the time.


John

[Dewey DTP]

Originally posted by Thumpin440ex
Hmmm that is very interesting with that.. Any tq numbers? The HMf run ran a fatter jet and still leaned out more then the sparks.. Yet up top didn't make as much hp, was fatter.. I am not to sure how well the dyno is set up. They can surly be persuaded. I know this coming from a hot rod back round, still into this kinda stuff.. Just seems like a very od dyno to me.. If the hmf leaned out, it could be flowing that much better then the sparks kit.. I think it was a possible issue with the lean spike, it happens all the time.


John

your points are valid this was jetted richer all the way up to a 200 main with the HMF and it did not like it.

my point was or is that a Sparks pipe shows brouder power and is easier to tune. i think it is the better pipe of the two.

Dewey

[dxcody]

Very nice dyno run, i have had a curtis sparks before and liked it but i think the HMF sound is better.. The curtis sparks i had wasnt very loud tho which is nice for in town riding and stuff,

but nice dyno run!