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SuzukiSavage.com
/cgi-bin/YaBB.pl General Category >> Rubber Side Down! >> Torque woes... /cgi-bin/YaBB.pl?num=1309224131 Message started by blackhalo on 06/27/11 at 18:22:11 |
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Title: Torque woes... Post by blackhalo on 06/27/11 at 18:22:11 So I've been experimenting with a baffled straight pipe (downturn/slashcut)... various baffles, from small louvered (10% blocked) to four way spikes (80% blocked)... packed and unpacked. I got some interesting sounds, mostly too loud... but then I began putting two baffles in at the same, things started to sound a lot better... warm! Now I haven't rejetted, or tuned anything yet... but the most obvious problem I'm having is the loss of power in first gear, it's just mush... no get-up-and-go! After I rejet, will I get some of this power back? I mean, the bike just feels weak. Out of curiosity, I put the old exhaust back on (after a few weeks)... now the power is back, but all the old issues are too. It's hard to start, slight lurching for the first 5 minutes of riding, always backfiring... so it basically runs like crap (this '09 bike only has 1200 miles on it!!!!). Did I mention it sounds like a hairdryer? ::) I've read the forums UP and DOWN... I've bookmarked various carb and rejet posts (which are excellent, I might add)... but I'm still unclear... can I get the power back with a baffled straight pipe? If so, where exactly do I find it... is it in the rejetting? I'm considering just tweaking the exhaust, then taking it to a dealer to performance tune it... is that a bad idea? I imagine they'll charge an arm-and-a-leg for a carb rejet... and they'll probably only run it once, turn the screw and send it back to me... does that sound about right? I'm not afraid of the carb... but I REALLY don't know how to tune it well (after I rejet)... and I REALLY want my power back!!!!!! Any advice? P.S. Sorry for the long post, this one has been weighing on me for a month now... |
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Title: Re: Torque woes... Post by justin_o_guy2 on 06/27/11 at 18:35:26 I'm considering just tweaking the exhaust, then taking it to a dealer to performance tune it... is that a bad idea? Yep,,bad idea.. you can do it yerself & youll learn a lot & you wont have to worry about them scewin it up & rippin you off for a load O $$$. Whats your elevation above sea level? Ohh, go with a KNown Good Exhaust design, No one is gonna be able to really help wih tuning on an unknown exhaust design. Thats MY Opinion,, someone else may jump right in & be able to guide ya thru.. |
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Title: Re: Torque woes... Post by Boofer on 06/27/11 at 18:57:33 To be very elementary, the engine is an air pump. Imagine it as water if you like. The flow must be optimized from the air filter to the exhaust. Mufflers are designed to hold or scavenge the exhaust gases as needed and help pull in the gas charge. This happens so fast it is amazing to me it works at all. Suzuki designed their muffler to work correctly in a wide range of circumstances. It's called driveability. You messed that up. Go big or stay at home. Start at the air box and slowly open that up as you put in a slightly larger main jet (150) and maybe an idle jet (60?) You may be able to get by with a carb spacer mod. Then see what you can do with the muffler. I have not done this on the Savage But it's regular auto mechanicing, or was when I grew up before fuel injecting. Take one step at a time and write down what you do. This is a single cylinder bike made for torque imo. Several on here have streetable bikes they have spent time and money on. They are happy with them and can help you a lot. Mine is set to run in fifth gear all day long and pass from 50-75 mph. It is not as quick as it was, but it's ok for my use where I ride. :) |
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Title: Re: Torque woes... Post by Serowbot on 06/27/11 at 19:00:25 An open exhaust will never have good torque... Jetting will help performance some, and is needed for engine reliability, but it won't bring all that torque back... Open pipes can make good power and even good torque numbers,... but the powerband is narrow and very high in the rev range... That's why Harley shorty mufflers are so popular here... They will give a nice tone, and you don't loose your wide torqueband... |
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Title: Re: Torque woes... Post by blackhalo on 06/27/11 at 19:40:57 The exhaust isn't open tho... it's got two baffles, about 16" long! So I've got backpressure, I just didn't get the torque back. As far as rejetting goes, I should just buy a variety of jets... then trial and error until something feels right... what range exactly? (start at 150... up to???) Like I said, I'm not afraid to rejet... but it's the actual "tuning" I don't fully understand... I read something about 4th gear, 1/4 turn on the throttle?? I city drive, so I just want my low gears back... nothing more disappointing than taking off from a stop light, and feeling like a golf cart could beat you out. haha! Anyone have pics of a crosscut stock muffler? I'd love to see what it actually looks like inside. P.S. Figured the dealer was a bad idea, I just don't trust them... my elevation above sea level is about 5 feet... I'm literally 2 minutes from the beach (which is great, when you're not working on your bike in the carport... no garage). |
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Title: Re: Torque woes... Post by Max_Morley on 06/27/11 at 21:37:06 Maybe too much baffles? If you follow the SuperTrapp bit, they tune the restriction by adding or subtracting outlet discs to balance the performance and noise level you want. Having tried many options from a Raask straight pipe w/o and with a muffler, a Supertrapp, a glasspac, I settled on the HD dyna as the best and cheapest option. Bagger has one with a center baffle and rated at 80 db on the HD. Sidecar tug has one off a 1340 cc HD that is longer as I wanted the torque and sound to exit past the car. Again a 80 db sound level on a HD, have no idea what it is on the Savage. Just works great, no frowns on people faces from noise and great acceleration from the get go on both bikes. There are some excellent posts here on here from those who played with baffle design. Use the search feature and set it to go back a number of years. Not sure exactly what words to use. Maybe some one has bookmarked them. They should be in the tech section. Max |
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Title: Re: Torque woes... Post by Serowbot on 06/28/11 at 00:23:43 Here's my basic carb jetting advice... FWIW... Quote:
I've now posted this tutorial in the tech section... Serowbot's carb jetting tips for beginners... (http://suzukisavage.com/cgi-bin/YaBB.pl?num=1309246277/0#0) |
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Title: Re: Torque woes... Post by dasch on 06/28/11 at 01:50:57 For reference: I had to rejet (larger jets - more fuel) when I went from stock to WIDE open 2'' muffler without baffles. Some HD performance piece I got on ebay cheap. What you did seems to be the oposite. You went from stock to stealth exhaust, it makes no sence it needs MORE fuel. In your shoes - I'd remove one of two baffles and test. It seems you closed it (sounds like a hair dryer??) too much. Hell, remove both and test. Find the problem first, before you apply a solution. ;) Post what happened. And-oh, don't take it to the dealer. Specially not in that "super turbo nitrous tuning shoot-for-effect" shop down the street. I doubt "performance" shops ever played with this classic thumper. It will cost a bundle too. ;) Time to get hands dirty. |
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Title: Re: Torque woes... Post by blackhalo on 06/28/11 at 11:53:14 Thanks guys, I'll guess I'll just have to do more tests! For the record, I've tested 6 different baffles styles (8" each)... with a variety of different glasspack, ranging from standard fiberglass insulation to stove gasket rope (for wood burning stoves)... I've tried one baffle, two baffles, three baffles... packed, unpacked, etc... I've been doing this for weeks now. I've even tried three different aftermarket mufflers... a true shorty glasspack, a cocktail shaker, and now a straight slashcut, all of them lose low-end torque. I've been testing DB levels at 25ft, it's down to 68DB at idle with a nice tone... (much louder at WOT I'm sure... but I'm not worried about that) What sounds like a "hairdryer" is the STOCK muffler... my custom mods sound better than anything I've seen on Youtube... except maybe the Supertrapp (but I'd really have to hear it in person)... and even then, people complain it's too loud. Mine is not too loud, it's almost perfect... I just want the power back... it's not snappy in the low gears anymore... so I guess I'm trying to decide where to make changes first... where is that power hiding? If I don't have to rejet, I would prefer not to... I notice a lot of people make changes to their bike, just because. I (understand the impulse, but) don't want to do that, my bike isn't that old. I guess I'll just work my way through the process and hope for the best... I suppose my real question is, has anyone successfully regained their low-end power after an exhaust change? |
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Title: Re: Torque woes... Post by blackhalo on 06/28/11 at 12:01:42 And thank you Serowbot, for that tutorial... excellent! Here's a few more good ones (for thread posterity): Lancer's Straight & Simple Carb Tuning: http://suzukisavage.com/cgi-bin/YaBB.pl?board=tech;action=display;num=1157720585 Carb Jetting - A Progressive Guide: http://suzukisavage.com/cgi-bin/YaBB.pl?num=1244217127 Great pics of carb breakdown: http://suzukisavage.com/cgi-bin/YaBB.pl?num=1191899985/0#0 Excellent map of each Jet and it's purpose: http://suzukisavage.com/cgi-bin/YaBB.pl?num=1104205157/1#1 |
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Title: Re: Torque woes... Post by Bubba on 06/28/11 at 14:46:00 here's mine http://i823.photobucket.com/albums/zz155/onelunger/IMG00224.jpg Gobs of power on the low end. I did have to rejet (see signature line). The big tab seems to provide the required backpressure and then beyond that there are little can-opener type baffles running down the pipe. I should note...my bike is LOUD. I have a friend that races supermoto and even he thinks it's LOUD ;D |
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Title: Re: Torque woes... Post by dasch on 06/29/11 at 03:30:55 I got lowend power too. Rejetted, 55 idle, 150 main, needle raised one notch. |
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Title: Re: Torque woes... Post by Routy on 06/29/11 at 04:39:52 I'm not sure you don't have another problem,.....loosing all this low end power just from changing to..... any kind of exhaust, open or baffled. Did it sound to me like even w/ the stock exhaust your bike is running ragged ?? If it were me, I would get it running correctly w/ the stock exhaust first,......even if it meant going to a Suzie dealer. Then modify slowly from there. I just don't think you should be experiencing this drastic loss of power that you describe, if there wasn't a problem in the first place. In my day, I have taken lots of mufflers off,.....cars and bikes,......run straight pipes,........till I got busted, and I never had any noticable loss of power,....in fact they always seemed to have more,......mostly illusion I know. |
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Title: Re: Torque woes... Post by arteacher on 06/29/11 at 05:20:00 78776D766A6C7F7D757B6C1E0 wrote:
+1. I agree with Routy. I put a Raask on mine and left the baffle in. I lost some low end torque, but not enough to worry about. (I didn't even notice it till someone mentioned that straight pipes cost you in low end torque). What I got in return was wicked acceleration on the highway. I will go to pass someone in 5th gear and before I know it I'm going 70 -80 mph. :o |
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Title: Re: Torque woes... Post by bill67 on 06/29/11 at 05:50:41 You don't know how much low end power you lose unless you tried some one on a high gear roll on with stock pipe ,then try it with a loud pipe,My brother and I have been doing that for years,And you lose the power were you need it and gain at speeds you don't normally drive. |
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Title: Re: Torque woes... Post by blackhalo on 06/29/11 at 12:43:31 The bike runs fairly well with the stock muffler... it's a little picky on startup, and the first 5 minutes of driving until it's warm... it's especially worse when it's cold in the evenings (usually HOT and HUMID here at the beach). But the AFTERMARKET exhaust doesn't have the same startup problems... I use choke to start it, then turn it off almost immediately and start riding (within 60 seconds). The thing runs like a champ right off the bat... like it's already warm. But I want my power back! Can someone explain these jet kits to me? http://www.jetsrus.com/a_jet_kit_street/suzuki_650_LS650P_savage.htm They don't look like "kits" (but that's what the website menu called them)... and I'm not sure what I should be buying... I don't want to spend the money on Dynojet, because I want to experiment with Stages I-IV... Dynojet would cost me over $200 for all four stages!!!! Just not sure what's included in a "kit"... do I need to buy a different needle, etc? P.S. @ Bubba: Is that the Custom Chrome 12" Drag Pipe baffle? I notice the backpressure flange is unique, I might try one of those. (loosely wrapping the baffle takes some of the edge off the bite, loud is good when it's a deep tone!!) |
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Title: Re: Torque woes... Post by Bubba on 06/29/11 at 13:05:02 http://i823.photobucket.com/albums/zz155/onelunger/th_sounds.jpg (http://s823.photobucket.com/albums/zz155/onelunger/?action=view¤t=sounds.mp4) Nope it was a "DynaPower" brand I picked up on ebay. It's actually a double walled pipe and the tab and baffles are formed from the inner pipe. Not sure if it can be found anymore... |
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Title: Re: Torque woes... Post by blackhalo on 06/29/11 at 13:06:39 Check out the very top baffle in the image, looks similar: http://www.retrocycle.com/CustomChromeSku/11230/12_Drag_Pipe_Baffles.html |
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Title: Re: Torque woes... Post by Bubba on 06/29/11 at 13:10:54 I think that might perform the same way. Somewhere out there in internetland I've seen where you can use a round washer welded to a bolt to create a "tuneable" straightpipe. |
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Title: Re: Torque woes... Post by blackhalo on 06/29/11 at 15:25:19 Tunable straight pipe... I tried it... actually, I just cut a slice into the baffle, then inserted a washer (and then did that three more times along the length of the baffle), it didn't really make much difference between 1 and 3. The problem is, I think the STOCK muffler has a ton of backpressure (maybe even chambers)... so one little washer isn't going to compare to the EPA crippled, coffee can maze that's likely inside the stock exhaust. I mean, when I put my hand behind the stock muff... it's like a little "poot poot"... there's pressure, but it's pretty minor... which makes me think there's some SERIOUS backpressure being created for this engine. That would explain why even my DUAL baffle design is losing power... it's STILL NOT ENOUGH backpressure to compensate for the original setup. Maybe... :-? |
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Title: Re: Torque woes... Post by Serowbot on 06/29/11 at 15:47:03 Give it up , and get a Dyna muffler... $20 bucks and the problem is solved... Torque will come back...;)... Info on choosing a Harley muffler is available here... Harley muffler guide... (http://suzukisavage.com/cgi-bin/YaBB.pl?num=1298689417) |
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Title: Re: Torque woes... Post by justin_o_guy2 on 06/29/11 at 17:18:25 382E39243C29243F4B0 wrote:
Yes,, like I said,, go with a known good exhaust system.. no one can help you while you have something no one has seen. &, Just like Counting the turns on an air fuel mixture screw so you can get back to square one if things dont go right, youve got to be able to UNDO your mods, when things dont go right, Things arent going right,, |
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Title: Re: Torque woes... Post by blackhalo on 06/30/11 at 01:18:34 Yeah, maybe... |
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Title: Re: Torque woes... Post by dasch on 06/30/11 at 02:29:28 hey, hey, don't lose steam now, man! ;) The stock muffler has chambers, of course. Gas goes all the way to the end, bounces off the end plate, tthen hrough a long pipe 2/3 length forward, then hit another plate... Something like that. But as lots of us said, we swapped it for something else and did not lose all that much lowend, and it was fixed with slightly larger jets and raised needle. |
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Title: Re: Torque woes... Post by blackhalo on 07/02/11 at 11:13:34 Hehe, I was just rethinking things... I'm also doing a lot of other aesthetic work to this bike, it's going bobber, with full tank removal, bars, etc. The exhaust is turning into a bigger project than anticipated tho... so I'm thinking now is not the time to be pulling the carb (over-and-over again), there's other work to be done yet. But, I STILL hate the stock muffler... so I might actually grab a Dyna and try that out in the meantime. Fyi, I just did another test run with a strongly packed exhaust... so the backpressure is huge, there's only like a Nickel sized hole for escape... no real difference, unfortunately. First gear just feels weak, it tops out early and brings nothing to the table... it's such a shame... because the rest of the powerband is pretty acceptable. So close, yet so far. :( |
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Title: Re: Torque woes... Post by justin_o_guy2 on 07/02/11 at 12:09:24 But, I STILL hate the stock muffler... Well,, I cant say have great taste, but thats a good start,, so I might actually grab a Dyna and try that out in the meantime. Thats a cheap way to see what the bike Will do, with a decent muffler. & Theyre good lookin,, I think youve effectively shoved a tater in yer tail pipe with all the baffling & packing,, its not breathing well at all,, |
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Title: Re: Torque woes... Post by blackhalo on 07/02/11 at 12:32:37 That crossed my mind... but don't forget, I did build UP to this point... I started with just the cam, then the straight pipe, then one baffle, then one baffle wrapped, then two baffles, etc, etc. If I remember correctly, the low-end torque has been missing the entire process... I always thought it would come back with the baffles, but it really hasn't. I'm also reading info that implies I'm running rich with the aftermarket exhaust (backfiring, popping, etc)... yet I'm at sea level, super hot / humid... how does that make any sense? I haven't adjusted ANY mix, whatsoever... it's all dealership settings... shouldn't it be lean? |
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Title: Re: Torque woes... Post by justin_o_guy2 on 07/02/11 at 12:35:17 Splain what you did with the cam... you mite want to find TDC & watch your valves,, |
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Title: Re: Torque woes... Post by blackhalo on 07/02/11 at 13:24:09 Did nothing with the cam... just removed the exhaust, gave it a spin bare cam. Yeah, that's loud!! Also, this bike is like-new... 1200 miles, and half of that is me in the last few months. It's from a dealer, it was serviced at 700 miles.. then into my hands, clean and new. It shouldn't have any timing issues. Anyway, I just went out a minute ago and removed one of the baffles... now there's a little more torque, but it's still mostly gone... and now it backfires hard with EVERY roll off (Sarasota, FL: 86 degrees, 68% humidity, 20ft elevation) I actually got a little freaked out crossing the street, because I can't rely on first gear to get me out of the way, that's how weak it is (it's a rush to 2nd gear). *sigh* I like playing with this stuff... a pita, but still amusing... it's just too bad I have to wait for the bike to cool down before I can make another change... very slow process. |
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Title: Re: Torque woes... Post by ralfyguy on 07/02/11 at 13:32:07 And every time you put the stock muffler back on the torque is back to normal? |
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Title: Re: Torque woes... Post by blackhalo on 07/02/11 at 14:11:00 Yes, exactly... stock muffler has great torque in first! Stock muffler has trouble starting though, needs choke... it also has some lurching in the first few minutes of riding, but once past that, it runs fine. Now my custom exhaust has virtually NO trouble starting, no choke used... it also doesn't lurch, ever... but that first gear is toast, second is at least serviceable, and everything higher seems fine. As mentioned... so close, yet so far. A thumper without low end, is just a scooter. :( P.S. Heading over to the HD dealer dumpster this evening... see if I can find myself something to play with! hehe! |
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Title: Re: Torque woes... Post by verslagen1 on 07/02/11 at 14:38:44 don't know why you'd get a different response in 1th then the rest of the gears. Are you lugging 1th too much? |
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Title: Re: Torque woes... Post by blackhalo on 07/02/11 at 16:19:04 Well, no luck at the dealership dumpster... lots of empty boxes, and it started to rain (no way I'm climbing in a wet dumpster!!!) Anyway, 1st gear with 'stock' muffler pulls hard up to 20mph, at least... it's peppy, feels like it's got some guts (it just doesn't sound like it thanks to the stock exhaust!) Now, 1st gear with my 'custom' pipe pulls slow and sounds like it's topping out just over 10mph... that's why I mention it's a "rush to 2nd"... 1st just doesn't sound good (or work well). The rest of the powerband isn't perfect with the custom pipe, there's a power loss... but it's not nearly as pronounced as the 1st gear, which is where all the FUN is!!! It's driving me crazy... but I guess I'll just have to get my hands on a Dyna and see for myself... that may provide some perspective. I'm just a little tired of spending money on mufflers... I've got three atm, and multiple baffles, fiberglass cloth, insulation and stove gasket rope... apprehensive to buy yet ANOTHER muffler! haha! |
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