Hi, pretty new to the forum. Building/restoring a 1975 RD350, hopefully ready to purchase expansion chambers soon. I love the old school look of the DG pipes but understand they are not the best performance option. I may go with Spec II classic chambers since those are pretty close and I don't want a separate aluminum silencer. My question is why are DG pipes not considered very good, is there anything that can be done to make them better if I wanted that look, or should I just consider other options? For reference I plan to use Y-airfilter intake, stock carbs/rejetted, TDR reeds, refreshed top end/cast pistons, with minor porting. Looking for a quick backroads street bike, likely won't race. Thanks for any help.
they are 'ok'. specII much better.
few reasons: very old design. they never tweaked them. also, theres no stinger section betweent he end cone and the silence on MOST of them. I -have- seen a very early set that did have one.
and, specII pipes at least new ones, have tapered head pipes. might also want to consider j&L retros or garrets millennium pipes. But, dgs are decent for what they are but they have gotten way pricey as of late. at 299 deal. at 500+ no freaking way. just my opinion. and yes ive owned many sets.
I had a old beat set that I cut up, and there was a short piece of pipe between the last cone and the silencer, but just loose and not welded to anything.
They do work noticeably better if you cut off the entire silencer piece and finish the last cone, add a stinger and silencer. Not worth it id you are buying a new set at full price though.
They weren't that bad when they were less than $300 new, but now they are over $500 forget it.
Another $150 and you can get Spec2 or Garrett's pipes which both make great power.
You can still find them for cheap: https://www.ebay.ca/itm/DG-Performance-Yamaha-RD-400-Exhaust-Pipe-14-4414/164464597588?epid=171183156&hash=item264ada9a54:g:mF0AAOSwWZdfkhIq
I wouldn't spend more than that though.
Quote from: Alain2 on January 29, 2021, 06:37:20 AM
You can still find them for cheap: https://www.ebay.ca/itm/DG-Performance-Yamaha-RD-400-Exhaust-Pipe-14-4414/164464597588?epid=171183156&hash=item264ada9a54:g:mF0AAOSwWZdfkhIq
I wouldn't spend more than that though.
I saw those but it says RD400. I have been looking for a few months and have not found ones for an RD350 less than $500. Unless those will fit an RD350?
I like mine, but don't know any better :dawg:
Seriously though, if they are that close consider spending more.
I really like mine. I have done the Dave F mod, TDR reeds, RZ style crossover intakes, 1/4" spacers between reed cages and cylinder, and individual UNI pods. Nice combo if I do say so myself.
DG's are easily the best dollar per horsepower gain out there, IMO.
at 299 yes. over 500 I disagree. go specii or Garretts pipes. not much more and way better return per dollar.
I bought mine in 2008 for $265.99 from HVC I had no idea they were that much now. They are the only pipes other than stock I have tried so I have no idea what others are like. I would like to do the mod to them I like the look of cans on the end. Time for A repaint this spring.
I think I mentioned this before but in the late '70s I went to the drag strip and tested completely stock vs DGs with + two sizes on the main jet. 1/2 second quicker ET with the DGs.
let me expound a bit further FWIW.
are dg's BAD? as compared to stock pipes? no, absolutely not. However they are def the clunky old school (and previously) budget minded choice ? yes there is a performance gain. NO its not the 13 HP you see claimed without other work being done.
In my experience the order, from my experience, has been stock, then j&r or similar, then DG, then kind of everything else above that in that order of performance. specII will work really, really well with stock porting. So do garrets pipes and some others. The pipelines i have work really well with stock porting as well and id put them between the dgs and the specII as far as performance gain.
JL pipes are really good as well, but seem to respond to porting and engine work to really work well. thats why i have them on the hybrid.
FPPs are great, IMHO on par with specII's perfomance wise.
then theres the whole Ktek series of which i have no direct experience.
theres LOTS more to consider. whats the end goal? whats the budget? cosmetic goals? fitment? are you going to just stick them on, rejet and done or are there future mods to take into consideration? how OK are you losing the center stand? or even bending or cutting the centerstand lugs off? the side stand fitment? these all come into play.
with DGs you will need to lose the center stand, and deal with the lugs, and consider side stand placement . to they are just as much work to get right. with this in mind, this could possibly open up options.
I'll say, one of the prettiest bikes i ever saw, believe it or not, was a 74 RD250 with stock paint and chromed DG pipes. But it just depends what you can find.
:tellit:
ok. ill quit rambling.
Often (at least in my experience), there are two three main reasons for running aftermarket pipes:
- Looks. These are the guys that just want to do a "cafe/brat/scrambobber"" treatment on their bike, and aren't really concerned about performance. Sounds cool, looks cool, good enough. DG pipes were the budget option for these guys and fit the bill perfectly. Goes well with clubmans and stock foot controls for the monkey/football riding position.
- Availability. I've restomodded quite a few bikes that arrived with thrashed and rashed stock pipes. Finding replacement stock pipes is expensive and difficult. Throw on a set of DG's and you are good to go. K2tec/Mizuno/other cheapo JP pipes fit in here too, as they are cheap/easy but performance is a bit suspect (no tapered headpipes, hard mounted manifolds, funky fitment ...etc)
- Performance. These are the guys that are willing to spend a bit (or a lot) more for modern pipes that fit well and make good power. Spec2, GRA2strokes (Garrett), JL/Jolly Moto, TSA, Mutt's, ToshTec, K2tec type 2, Glyn Larrabie, M77, Performance Fab, etc.
Of course, there is a lot of overlap in the venn diagram, but when shopping pipes, you gotta figure out what camp you're in, and work within the parameters. Easy enough to just start out with whatever used pipes you can find for a good price, and work your way up as the opportunity arises.
There 'will always be a market for used expension chambers. No reason (IMHO) to buy new DG's for over $500 when there are lotsa better used options out there for less.
I can give some insight here as I recently went through the same experience.
I have a 75 RD running FPP pipes with short silencers. No porting work on that engine but all the other standard stuff, (reeds, cross over, y boot etc.)
I was putting together a R5 last winter and was planning on pretty stock engine and went cheap on a set up DGs I found for around $300.
Long story short had a bad bottom end and changed the engine to a ported RD. Wish I would have spent the money on Spec ii, Garrett or JL. Will be upgrading this winter.
The main difference to me is not as much about overall performance as I am not riding these on the track but more of what I would describe as feel. There is something about the sound and responsiveness of the DG that is just not as good.
My FPPs have a crisp higher pitched ring and yes some of that is tuning but it is just more of what we want out of a 2 stroke IMO. The DGs have a lower growl to them, yes its louder than stock but still more of a rumble. For all intensive purposes they are fine and I do like the look of them but they are lacking in excitement. They are like the SV650 of pipes where JL would be an MV Agusta.
So as everyone else has said it is just a matter of what someone is looking for.
Without putting a fairly serious program together everybody is just guessing on combinations of mods. Butt dyno's are notoriously full of poo. There are however very obvious aesthetic and financial reasons for choosing different pipes.
That said, $500 plus is silly for DG's. They just aren't all that nice. Even after the stinger mod, redoing the flanges, and just generally reworking them, they are still pretty brutalist. They do run nice and sound nice though. Of course I got mine for $275 shipped, so I really never entertained better pipes as Spec II were like $650 at the time as were most others.
overall performance and real world readability aren't poo. No one was giving dyno numbers, but my reference to the DGs '13hp' were from an old ad thats misleading.
But, I have run multiple versions of all the pipes mentioned except for the ktec, and the millenniums were the motocarerra ones on various setups. Just giving feedback.
.02
To be fair, I never said you were wrong, I said butt dyno's are unreliable. The point is that picking and choosing pipes based on port configurations, intakes, etc., and then making claims about what works and what doesn't isn't really supported by data when using a butt dyno. That is a problem.
yeah, but no ones talking dyno numbers either really. it was a more 'what works' and the assumption was stock-ish porting (basically clean up) road going bike that's enjoyable to ride. Judging by the mods, the dg would do fine, but for close tot he same $ , there are better quality examples. and again, theres all the other things to consider. aesthetics, fitment, etc which have zero to do with performance.
reality is, ride enough of these bikes with different pipes and you can feel what works and what doesn't on a 'typical' setup like this. its very easy to go down the road of dyno numbers, lap times, port matching to pipes (which only works by trial and error after the initial design is hammered out by the numbers) etc.
I'm not being argumentative, you are 100% correct. but this isn't going to be a HP monster either, which leaves some leeway depending on the other factors aside from just 'which makes the most power'.
I rode chucks RD400 with those crazy beautiful chambers he has a few years ago, big money turner pipes i think, a few years ago. I actually preferred it with the specII's, as i think he did, for street riding. And thats what went back on last time i saw him. and ya KNOW the turner pipes were designed right. ;)
Thanks for all the info. It seems obvious it is not worth spending $500 on DG's. I would probably still pick them up if I could find some under $300 and upgrade later if needed. But I am likely going to go with Spec II Classics since good street performance is important and I don't want to give up horsepower if I'm spending over $500.
Chrome DG's
Don't tempt him! :dawg:
I have a pair of chrome DG's! Been looking for info/pictures on them for years. The picture above is the only one I've ever seen. Found them on eBay a few years ago while hoarding parts! I figured they would be more for show than performance. I also have a pair of beat up spec II's that I would like to "restore". Looking forward to the comparison (once I finally get the bikes back together).