Jaz240

iTrader: (52)

Ok so I dropped The JPX.28 in my Hyper st, and all is can say is " HOLY CHIT" !!! Break in time is 20 minutes, or about 2 1/2 tanks, then you start race tuning. I only had to lean it out about 1 turn on the high speed, and 1/2 turn on the low end, and WOW!! My truggy burns rubber on asphalt! I can't believe the ease of tune, reliability, and Power! 20 minute break in! I did have to heat the sleeve to 220 degrees just to get it to turn over, but that was kinda fun, knowing it was so tight, it needed that much heat. I haven't even matched it to the right pipe yet. I broke it in with the JP-3. This engine is insane! I bashed it around my parking lot, and a little off-road for about an hour, and the power is incredible! For $200, I see no need to ever buy anything else. I would highly recommend this engine for anyone in the market for a new Truggy engine

____________

moeman

iTrader: (26)

Sounds great but....nice honkers!

Jaz240

iTrader: (52)

LOL. I love all my fellow RC ers so much I give you that to look at instead of pictures of my Rc cars, or my ugly ass!!

stiffler297

Get the ofna 053 header and the 2027 PCR pipe. You won't believe how much more power you will have with that combo right there. Bottom end is perfect, not to much but enoough to clear some doubles out of a 180 degree corner and the top end is just STUPID crazy.

Jaz240

iTrader: (52)

I know. I'm the same guy who PM'd you 50 times asking you which pipe I should buy on Ofna's website. The pipe is on it's way. Thanks again for all your help.

PerryJ676

I have been running the stock RTR Losi sport pipe that came with my truggy. I just yesterday ordered a 086 after reading good things about them matched with this motor. Was that a mistake? I looked at the 053 as well, just didn't read as much info about the pair as with the 086.
I have also read that the conical headers may be worth trying, anyone know if the short/med/long would be the way to go?

Sorry, don't mean to hijack, but to add - yes the jpx is awesome in my experience. Breakin was easy (I did heat to 200 before the first 5-6 times running it) and even running fat it screams!

I am going to do try some fuel flow porting to try and get a little more mileage out of it now that it's got a good amount of fuel through it (if anyone has pics of thier modded sleeves, I would be your biggest fan if you could share with us!). Also ordered the 7mm venturi to try with it. May end up trying 7.5 too.

Either way, as somewhat of a new guy to offroad nitro, I love this motor. It's a huge upgrade from the Mach 427 (which I find a great motor considering its in an RTR).

moto431

iTrader: (10)

what kind of run time are you guys getting on a race tune. while on a track. thats the biggest drawback from running a 28 is the run time.

Jaz240

iTrader: (52)

The JPX .28 gets its best performance with the 2027 pipe using the double bent medium manifold. Its the .21 that works best with the 053 pipe. The 086 pipe is high rpm pipe, which will give you slightly higher speeds, but less fuel economy. both engines work best with the double bent medium header. I have not gotten any track time yet, so I am not sure how long a tank lasts. I'll start tweeking only if I do not get 6 minutes, because that's how long our qualifiers are. Send a PM to Maximo, he runs nothing but Jammin engines, and he has all the answers, he also does Modifications on the Jammins for HP. Porting, fuel, and race. also try Stifler, he was really helpful for me, he answered lots of my questions, and told me the best pipe/header combo's for both the .21, and the .28

Twotan

iTrader: (3)

i just put one of these motors into my x2. It is a great motor break-in was easy and tuning was easy also. It is one of the best things i have bought alone with this x2. It seems to be a easier motor to tune then my Nov's. The power is great, the only thing is it's a little heavy on the gas. May be i will lean it out after a few more break in tanks. Thank you Jammin for a great motor.

stevef

what venturis are you guys using with this motor? i have the stock one in there now and i want to use a smaller one. who has one that will fit in stock? ive done some searching for jpx/picco venturris and i havent come up with anything yet.
-steve

Jaz240

iTrader: (52)

Nitrohouse part Numbers:

Picco/Jammin restrictors:


51427= 7 MM
51428=8MM
51429=9MM

they are about $7 each

Ariesatplay

I should have my JPX.28 5/15/09 it's been on back order so it must be a good engine. I just wanted to thank you for pumping this engine up a friend told me about this engine this the engine that I'm going to learn how to club race with I just have one ? What's wrong with the j-p3 pipe because I have one already for this engine will I need the 2027 ?

tristyn

iTrader: (4)

nothing wrong with the jp3 on that engine. The JPX is the best $200 dollar engine I have ever ran. I replaced the bearings after aprox. 2-2 1/2 gal. with TKO ceramics and it now has aprox. 8-9 gallons. I have not ran this engine for about a year, but when I quit running it, it still had a ton of compression and was still running awesome.

losifiend

iTrader: (73)

I had a JPX .28 in my 8ight that I ran about 8 tanks through and was inpressed just like you. I went up a few teeth on the clutch bell because of teh insane torque and was even more impressed. Now its just sitting on my work bench since it has too much power for my SC8, since I converted the 8ight to electric.

Too bad I cant use it in my LSt2