Performance gains with pods/rejetting/pipes?

I know the technicalities of pods, jetting, and pipes have been discussed here before, but I was wondering how much of a difference they make. If you do all three mods and get the engine breathing really well and getting the right amount of fuel, and really get it dialed in, how much more HP and Torque will be added? Does anyone have dyno numbers or some personal experience? Thanks.

 

In my humble opinion......
If you want more power, get a bigger bike.
Pipes and jetting does more to smoothe out power delivery than anything else. They are also very expensive for the amount of power boost that you get. If you had a $10,000 sports bike and you want to go a little faster, $750 isn't that much. But if you have a $750 XJ, $750 is a lot of money for 10 HP Proper jetting can also be very tough to do, it's easy to lose a few horsepower with pipes if you don't know what your doing. If the goal is to have a great sounding machine, thats a whole other story.

 

I agree - it will cost you close to $1000 to do it right. You can gain close to a 20% performance boost, but it does come with some caveats. You will be working the engine harder, and it will wear out sooner. Anytime you take a bike away from its stock set up, you need to perform maintenance more often, i.e., changing the fluids, checking clearances, etc.

20% performance increase on a light bike of this style is definitely noticable.

It is a lot less painful to buy a larger bike...unless you really love your bike and enjoy doing this sort of thing...which I do both.

YMMV

Michael

 

$1000 sounds like a really high estimate. Pods for about $50, I can probably do pipes myself for 50-100 bucks, and another couple hundred for the new jet kits. That only comes out to 300 or 400 bucks max if I tune it myself. Does that sound right?

 

Pods: $40 from ebay
Dynojet kit: $100 if you shop around
Mac 4-1 exhaust: $220

Total: $360

To buy the correct tools to tune it in yourself might cost another $100, but still, I think you guys are estimating way too high. Now, if you have the dealership do all the work, I can definetly see $1k coming real quick.

And I'm getting tired of the "if you want a faster bike, buy a newer one" line. Some of us can't AFFORD a new bike, and rather enjoy modifying the ones we ride. I don't know about jasonlion, but I started out by hot rodding cars, have now moved on to bikes, but haven't lost the passion to make things go faster! So to you it might not be worth it to be able to reach 60 mph a half second faster for an extra $500, but to us it is.

Sorry for the rant, I just get tired of all the negativity sometimes. 8)

 

Again, convention verses desire. I'm glad we can still tinker with our toys. Give the government a few more years and that too will be gone.

 

Jet kits are a waste of $$$ ...
Tell me exactly what jets you have and send me a fiche of the pipes etc ... I will use my air max as the basis for engine design, valve sizes etc ... and I will conjuse up a set up that will leave you 1-2 tewaks away ... best of all ... free ... you then buy jets and fiddle away ... and post back here where you are and how you got there ... that is how we jetted the GS500 back in 1999.
I verified it all with an O2 sensor in the pipe ... it may take 2-3 tries from 2-3 people to get it on the nose ... but once done ... it will save everyone atleast a 100 bucks a pop.
I can tell you within a jet size or 2 ... and from there it may take your 3-4 swaps of specific bits ... you remember that slow and 1 at a time changes and test it out thoroughly ideology right ... use that and tell us when you have it done.
Cool.
Srinath.

 

I see no one has really answered your original question very well Jason.

First of all, modding your bike will not add more than a couple of HP if any at all. Pods and pipes will however increase your performance by making you bike more responsive to throttle requests. The biggest key issue as to whether it is worth doing is the condition of the engine. If the engine has good compression and valves have correct clearances then it is worth playing with.

Essentially if your bike runs great now then you can make it better, but don't do it if you think it is a cure to any current problems.

I now you didn't request any info on costs, but apart from the cost of pods and exhaust the jetting is a minor cost. Over here the jets can be picked up for $7 each. You will need a few sets of jets to change while you fine tune. Will take time but thats the fun of it. All up shouldn't cost more than $400.

And my comment for the nay-sayers. It is up to the individual. I could afford a new bike but I'm buggered if I would waste my money on them. Water cooled computerised plastic covered crotch crunchers.

Buy a bigger bike? Yep Just did. 78 XS1100 with pods and pipes but PO didn't rejet. So should I put it back to filter box and standard pipes? Not on your nelly. I have a love of a good old classic bike and am totally happy to throw money at either of mine. Again, up to the individual.

I'd do (and have)what Jason is thinking about just for the sake of it and to broaden my mind on the possibilitys of what can be done. It's all a learning experience but I like to challenge my mind and skills to expand my horizon. Not buy a bigger bike just to ride over it.

 

One small point I disagree on hired goon ...
The peak power ... I have seen 10% on the GS500. On the maxim that exhaust is a freaking slug and its like trying to breathe through your fingernails ... toss the pipes and you lose 30 lbs, free flowing pipe and filters and I see 10% easy. In reality will feel like you gained double that ...
Cool.
Srinath.

 

Horsepower is mainly achieved through mechanical means. Eg, Bore and stroke, compression etc There is only a certain amount of extra HP you gain get from using pods and pipes to make your engine breathe better. Most HP gains from this method on the dyno are usually wont acheive more than a few percent more total horsepower.

Of course, if you are swapping from a twenty year old stock exhaust that has carboned up baffles, then yes, the increase could easily be 10%.

Now, increase the compression, oversize valves, port and polish and that is another story. You can only get so much air into a stock engine unless you do serious mods to the top end.

Now who's up for a turbo. :twisted:

 

Well - pods and pipe will give a bit of hp because you're opening it up. The next bottleneck would be the intake/exhaust ports. If you knew someone with a good bench and knew what they were doing - I bet you could pull quite a few more ponies out with a nice port/polish.

The problem people have experienced on some engines is that they were designed with a specific target hp in mind - meaning harder working engines put more stress on the internals which can lead to failures... what I've heard from the 250 crowd is that the oiling system isn't up to the task and that the gallies would need work to get enough oil flow to the top to keep it solid.

A simple pipe, jet, pod isn't going to be too expensive and would offer a few more ponies. You'll probably loose a bit on the bottom end and gain a bit on the top end. Personally I do like the decent bottom end pull from my engine as is but if you want the more sporty top end this is the way to go.

As for the new bike comment. I'm one of the people who say this. Let me first say it's normally reserved for the tire kickers. I frequent a 250 board and it is not IMHO feasible to get enough hp out of that bike to compete with the 600+ sportbike crowd some of our riders hang out with. Buying a different bike would really solve their particular problem better - or simply understanding and accepting the limitations (and rewards) of your current bike.

Often we get people ask - is it possible. Typical response is not easily/cheapily. Then we get questions of what about a turbo, NO2, supercharger? Sure - big hp gains but the 250 engine will not support these. We know because big land speed record people have done it and shown us what happens. The top blows off ( head can't support the preasure) or the crank doesn't get enough oil and spins the main bearing. In reality - pulling more power out of a bike than simply a pipe/pod will stress the engine and should be considered very carefully before stepping into... hence the fast and easy (maybe harsh, maybe misunderstood) buy a different bike response.

In this case - for this particular poster. You can see modest gains for the money. You will feel the difference. If you are a serious hp hunter and don't want to be a serious modder then perhaps a step up in the xj class to the 750, 750x, 900 or 1100 would be a reasonable move. The trade off in weight might be an issue for you.

Myself personally? I love the xj. I realize the xj is no sportbike and I do still drool over the sportbikes. I'm seriously looking at zx7r's in the area... along with some speed-tourers like the XX/busa. People often call these bikes crotch rockets or compensating... I at one point might have thought that way... but now I recognize their merit. Four hours of boring straigth roads in northern maine is a place for a speed-tourer. Maintaining a sane, loping cruise with great windprotection and range.

Locally a used sportbike sells for a maxim + the cost of a pipe... buying the sportbike gets you the hp, the handling the xj could never have and doesn't put any stress on the engine at all... I realize they aren't for everyone and are not all to my liking anymore - I've got enough hip problems as is that a zx7r is never going to be my primary touring bike - a XX might on the otherhand.

Anyhow - I've wandered on and off topic ... woot

 

Even if the pipes aren't clogged (and a decent bruning bike will not clog pipes) ... the maxim's muffler is the equivalent of a noose round your neck.

And they are heavy ... lose them, jet the bike to the pod and filter (and no you'll not lose low end if you jet it ... if done right) ... slap on decent suspension front (progressives) and one of those IAS types on the rear and decent tires ... and you'll see a 10% gain on a dyno and your ass will tell you that you've gained 2-3 times as much ... heck I trust my ass ... its never crapped out on me ... Oh wait ... OK forget that ... its a good ass none the less ... always there when I need it ...

Better yet ... these old bikes ... look like sheiete, sound worse, leak oil sometimes and generally embarass everyone that is on it and near it alike ... but guess what, it'll never get stolen, doesn't need full insurance, is cheap to insure otherwise, parts are dirt cheap ... and best of all will run forever ... Buying a bigger but just as old will only get you so far ... say you buy a 1100 maxim ... then what ... its not neccesarily a lot faster than the 700 and its heavier ... you'll still get creamed by a snot nosed kid on a CBR600RR ... but you'll be riding long after he's eaten his motor from racing with too many old ass bikes ...
Cool.
Srinath.

 

Thanks for all the responses, guys. Very informative.

 

On insurance. With my current company a sport bike is prohibitatively expensive. They require all kinds of things - alarms, full coverage, locked when not in use, etc etc. God help you if you ever got a ticket.

I've looked around and found a good company to deal with. My insurance rate for them is either 0-450cc, 450cc through <750cc, and >750cc. Through them I pay the exact same ammount to insure a 600rr and my 650 maxim. It is only for PLPD. Good deal in my books.

Shopping around for insurance will save you a mint.

As for the low end power loss. From what I've seen on dyno's you can loose a bit 1-2hp in the bottom 3-4000rpm. You can gain as much as 10-15hp at the top end. I'll try to find a comparison dyno - certainly you'll feel it and certainly the bike will be lighter. No arguements there.

I will argue on the sportbike front. I've ridden and owned both an xj and a sportbike at the same time. I don't think that moving to a sportbike will turn you into a squid - although it certainly will bring it out of you if it is there in the first place. Sure that's splitting an awfully fine hair - but if some one wants a lot more power or a lot more sporty a feel then they will only get it from either extensive modding of the xj or buying an old sportbike... even an 86 ninja 600 will feel like a rocketship...

Personally - I love the xj650 and think it is more than enough bike for me... but we all can see greener grass whether it be a new muffler or some fancy touring package.

 

Insurance ... with my present company a 600RR will be much more than a old ass maxim. Of course an old sport bike (over 10 years old, they just consider them to have lost their sportiness ... ) will be same as a maxim for liability.

A old 600 ninja will not easily out run a air maxim except on top speed, and its mainly due to aero ... its going to come up against much stiffer opposition with the water maxims. but still aero's are going to hold their way after 100 or so ... but in town and in traffic both the maxes will hold up well against a 600 ninja and similar. seca ... maybe different ... the 550 might fare worse, 650's a bit better, 700's OK ...

And here is the killer ... if you jet it right ... (and from the factory they were far from jetted right) low end power loss isn't the norm. However when riding it you may think its lost power ... the same way a servo controlled V max actually fells like it pulls harder with the servo working like stock ... when they wire it to always stay open ... the bike gets so smooth and pulls hard everywhere ... it makes you believe its lost low end.
AKA ... a bike that has a sudden burst of power starting at a specific rpm say 3000-4000 ... will feel to your butt that its more power ... you dont detect power ... you detect changes in power ... a smooth and near linear curve will be barely perciptible ... you'll imaine its lost it.
These things came non ideally jetted from the factory ... set that right and you'll gain, then pipe and pods ... gain more ... all the way across.
Just cos you're revving past the low rpm like its a bottomless pit isn't a loss in power ... its just smoothed itself out and doesn't hit you with the jerky surges in power ...
Cool.
Srinath.

 

I have rejetted recently. Pods and pipes were already there, so I just did it. I got the Dynomax kit from MAWonline, and IT CAME WITH A COUPON FOR A FREE DYNO RUN at "participating" locations... I dunno where these places are, but I haven't looked, either.

So, to answer your question, Jas, if you do rejet yours and pod it, etc., and you don't get a coupon like mine, just PM me at that time, and I'll hook you up. I won't be using it - I'm not really concerned about how many horsies my wheel is puttin' down. I just wanted it to run smoothly.

btw: dynojet kit $106 total

 

Jason, what did you decide to do ? doid you make any mods, or are you just running her as is stock ?

 

Getting a dyno run with an exhaust gas analysis can be a great tool for tuning. RWHp readings from a dyno are highly subjective. The value is in multiple runs on the same dyno. This allows you to compare runs to and see what the tweaking has done. I too got the dynojet kit, and free cupon. There is a dyno pretty close to me, although I haven't called for the XJ yet. I am waiting on my colortune, and YICS tool.

My XJ has pods, exhaust, and jets. Right now, I believe the needles are set too high, and I'm rich in the midrange. Once I get her tuned and dyno'd, I'll know for sure.

Nachoman

 

Can't comment too much on the performance gain part, but I can recommend an insurance co.

www.bike-line.com

I pay 106 a year for liability for the XJ and they also have 24hr roadside assistance program for 14 a year (which came in very handy on my old Suzuki when the electrics melted and I had to get it towed)