Im a little leary with superbikes airbox mod. It seems its such a large opening on the back of the airbox. Seems to me that would be an exellent door for dirt, water or even a mattress to get sucked in there.
Why is it that most Raptors, LTZ 400's, DS 650's, Honda 400EX's that are modded (and RUN WELL WITHOUT POPPING and BACKFIRING) do so? Well, about 75%+ that I have ever looked at are running slip-on K&N or Uni filters, or some type of panel filter WITH NO AIRBOX LID.
To me it all seems very simple...the engine is an AIR PUMP, with proper air to fuel ratios of approximately 13-15 to 1 Air to Fuel. Yet our Predator came from the factory with an 1 1/4" snorkel hole as it's only way to breath. I am going to do everything I can to try and figure out how to make mine run well with a slip-on K&N, and since Dynojet also sees that viewpoint, and offers a kit that has a stage III set-up for a slip-on filter, that's where I spent my money.
I also like the fact that they're not trying to charge a lot!!! of money for an air box fix, that could be done much cheaper through other means.
Yes but all Gary's kit includes are a couple of jets. The DynoJet kit includes a new needle too, and as JJ pointed out, it has a Stage I and Stage III setting.
Granted his has the ability to make more power, but I think the machine will run better with the DynoJet kit. In other words, if you really want the best, get both. Use the DynoJet kit in place of the jets that Gary includes.
I keep referencing the fact that the other performance quads, at least out here in California, that are running strong...all seem to by running slip-on filters, either without airbox lids or airboxes period.
I have raced against these people, watched them race each other, and watch them ride the dunes and desert, all without any apparent problems. If all these quads needed an airbox to make good power, there would not be any slip-on type filters, and I'm sure everyone would be lined up at Polaris Industries to try and copy their ingenious air box design from the Predator.
If everyone who is doing anything with the Predator agrees that more air is needed, including Rath Racing and Gary at the Superbike Shop, then why aren't they trying the quad with a slip-on? My guess is that they live and work in the northern midwest, where snow, ice, water, and muck are the norms, and they will probably have a much better MARKET for the stock style airbox mods and kits they area offering. I am not knocking that approach, and I'm sure their kits will work well. I even appreciate and respect their work and talent in this arena. However, in my world, a slip on is alot easier to justify, and it removes alot of extra weight, plumbing, and things that can go wrong...and I'll bet in the end it will make more power.
Dynojet tested their stage III kit on the same dyno used pretty much industry wide, hell, they make the dyno. I don't think they would offer the stage III option if it did not work well on the dyno...they are a large company, and have been around for many years, I don't think they want the problems of marketing a kit that doesn't work well.
I don't mean to slam anyone about this, I'm just really interested to see what the Predator will do with a really GOOD exhaust system and a slip-on that flows as much as the bike wants to breath.
If someone has a good answer to these questions, please respond...I want to learn more...
The problem with the CV style carb is the balancing act when you modify. It's tuned to run with the stock set up, when you alter that you also need to alter the carb to match. The slide works on vacuum and spring pressure and to the average Joe it's just a guessing game trying to make it work right. Going to a clamp-on style filter your decreasing intake vacuum so the slide spring would need to get softer and the vacuum port may need to get larger for the slide to operate correctly. The CV carb has a lazy response compared to a pumper, that is part of the reason the Pred is somewhat deficient in the lower rpm range, you'll have much better response with a different carb unless you can find someone to supply exactly what you need for the stock cv carb to work with your modifications. Personally I'm in no rush to buy the first aftermarket gadgets that hit the street, it takes time to do the r&d on things that actually work. If your just looking for minimal improvements the jet kits and airbox mods may be all you need. I'm waiting for internal pieces that will make a more substantial increase from stock. Remember the the stuff you buy now may be useless with more in depth mods so it boils down to what your looking for and what you want to spend. I don't neccessarily believe all the hype that comes with the new latest and greatest products, dyno #'s can be so misleading or even manufactured that I don't rely on them at all in advertising. The headpipes are ready for a stronger motor and whatever slip-on you choose will be an improvement over stock providing the carb can be set up to match so I don't see the need to spend big money on a complete exhaust system. You need to think total package when performing engine mods so all the pieces compliment one another otherwise your just waisting your hard earned dollars.
I must say this is all confusing. I will take your advice and get the dyno jet kit. It will be here tommorow. What is the set up of the pipe. How do set the slip on up. How many disc, quiet core, cover etc. I would really like your opinion and to hear about your set up and how it works. Thanks to all again.
P.S. also thinking of getting the 580 engine kit installed as soon as it's available. What do you think of this kit and it's claim on 40% increase of power.
I that a 40% power increase would be great with the bike making around 60 horses with the 580 kit. However i think it would benefit those who do Sand drags and such a lot more than us eastern riders. The quad seems to have a little too much wheel spin at times and with 17 more ponies it could get nasty. Also putting that much more power into the quad could take away a lot of the good qualities of the Predator. For instance, i really like to do steep hillclimbs and the front end stays down better than anything out there. That much more power and its gonna be hard to keep it down. All in all i say the kit could be good or bad depending on rider ability and terrain.
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