HPI ribbed pipe tune issues

[romper4444]

Hey guys, just added the ribbed pipe on my 4.6 rtr Savy. truck was originally broke in on Byrons 30%, Can not run this fuel after adding the pipe as no amount of richening will bring temps down, peaking 300deg's. Added extra .2mm(I think) head shim(smallest one anyway), didn't help, now running 25% O'Donnell, and temps are exceptable at 250, but still not like the 215 I used to run with the stock pipe and 30%, I even ran Gen2 33% Byron Race and the truck friggin' screamed, TONS of power and still temps at about 230, that was with stock shimming too. It's like with the pipe the engine makes so much power it can't stay cool stay cool, helps with body off but still not enough. i tried the pipe on my Stock Losi rammintaor, M26 mb, one .1mm head shim too, and holy crap, i'm peaking up to 315deg's. What is going on here??? is this normal, I want to run the best pipe around, a JP-3 on my Rammy, but will I overheat it even more, I've never heard of having to shim a head maybe even more than I have allready have to keep temps down??? Whats the point of a pipe if I am taking away all the compression and losing power anfter the pipe just gave me power, Do you guys also recommend the HPI polished pipe as well, does it give nice bottom/mid range, as compared to ribbed pipe? That's what I want. The ribbed does seem to be quite an open chamber single design, with quite a large stinger, is this just a badld designed pipe, or am I only supposed to run 20% with a good pipe?

 

[Bankrupter]

The ribbed pipe is not a high end pipe
You can not get top end out of that pipe and that's your tuning issues now. The polished pipe is a very good pipe.

 

[Shaun]

yeah the hpi polished is a great pipe for a really good price!!!!

 

[X]

Also you should be running cooler with higher % nitro. Have you tried a different pipe to see if the temps come down? if not you are probally looking at a bad air leak.

 

[HPI_Savage_RC]

ALL HPI pipes are complete crap. The polished pipe is good for making engines sound loud (And if it is louder, it MUST be more powerful!!!!!!!), and the ribbed pipe could possibly make a decent silicone gel mold for use in a certain non R/C related application, but otherwise, they are useless. Both have absurdly large stingers that decrease backpressure and cause engines to run lean at high RPM, and the ribbed pipe isn't even a tuned pipe to begin with, more like a canister muffler. Anyone who thinks either pipe works well has no conception of how a nitro engine should run.

Any of the common buggy pipes (086, 053, JP-2, JP-3, etc) will give you MUCH MUCH better performance.

 

[JohnH]

easy there HPI_Savage_RC on the tone. You can state an opinion without it being so harsh please. If money is an issue the hpi tuned pipe is ok. The ribbed pipe is terrible. Toss it. The Hot bodies top end pipe is good so are the JP and ths pipes. JP4 I do not recommend do to it is a roar pipe and modified for sound issues for roar rules. The jp2 is better in my opinion than the 4. Little more do a Buku. It is all a question of money and what you want the truck to do. Bashing the polished pipe is fine. The F4.6 has a high operating pressure so the stinger diameter isn't that big of an issue. If you go to a motor with a lower operating pressure than you will get into a problem with it.

 

[oregonmud]

I like the Hot Bodies tuned pipe myself. Its not too hard on the wallet either.

 

[romper4444]

Awesome replies guys, HPI_Savage_RC, I sense that maybe you've been told maybe in your amature days that the HPI pipes would do wonders and did nothing but cause you problems, is that where the hostility comes from?? The ribbed pipe did give the Savy quite a power increase, and the Rammy despite its major overheating issue, absolutely screams, as the stock pipe is not even a pipe, its a muffler. My LHS guy told me that the ribbed was a top end pipe, now, I don't always take his word for things as he is usually wrong about tech stuff. Single chamber is bottom end, but I've heard the ribbed thing changes that??? I don't know, maybe why some say its more of a top end pipe??? I don't think the HPI polished pipe would be that crappy as it does mimmick some of the better 2 chamber pipes, and for 30bucks, I definetely think that you get the power increase that you pay for, it would be better than stock I think and would suffice as the 4.6 propels the Savy like a rocket stock, so a simple tuned pipe is all it needs. the large stinger thing is true, but I've read as well that the high press. thing on the 4.6 allows this to still work okay, I guess thats my answer then as to my Rammy overheating, it leans out on the top end, which makes sense because as long as I keep the revs in the mid to low range, it doesn't overheat, somebody is very wise here!! I'm looking for a low to mid range pipe, without any top end sacrafice. the JP-3 is a 3 chamber that from my research would do all that and more, would queit it down too, which I want as the Savy and Rammy can aggravate the neighbours!! I will put it on the Rammy and i think get the hpi polished or keep the ribbed on the savy, as i do have it running satisfactory now, maybe once i go back to 20% I'll be more than okay. Now the JP-4 is supposed to be the race pipe that is designed for the track, I've heard that they are all excellent, but most people for bashin say the 2 or 3 is the way to go. what about the 1, do want a lot of bottom end, but maybe it will be to much of a loss on top?? Does anyone know though if going to a high end tuned pipe causes engines to run hotter than normal?? I was under the impression that you just retune, and temps should be about the same as before, unless its a pipe not made for a certain engine. If I wanted to go the cheaper route for the Rammy, (the JP-3 is 100bucks at my LHS, and the header that I need is another 20, add tax and I'm lookng at close to $150, YIKES!!! ) the stock LST 2 pipe is great and cheap, i think its the same as the Losi HT pipe, they look identical, but one is polished or anodized, AND there is an open package Dynamite pipe that also looks alot like the LST2 pipe at my LHS, for $25, I'll need the header, but Dynamite makes Losi performance stuff, so maybe it is just a rebadged LST2 or HT pipe, anyone know this?? Man I'll stop writing know, crap this must be a novel, I'm new to the forum thing, just got so many questions and idea's that go through my head, maybe once I post enough threads on here, i'll finally get them sorted out, you guys have been great help so far!!

 

[HPI_Savage_RC]

Romper: Paragraph breaks, man!

HPI_Savage_RC, I sense that maybe you've been told maybe in your amature days that the HPI pipes would do wonders and did nothing but cause you problems, is that where the hostility comes from??

Yep, but not necessarily problems, just poor relative performance.

The ribbed pipe is a brilliant marketing strategy, it was designed with appearance and sound in mind to impress the n00bs. It doesn't work well on any engine, at any RPM range in my experience. Sure, I thought it was an amazing pipe when I first ran it on my Savage 4 years ago, and I thought the polished pipe was even better. Until I tried an Ofna 086, I had no idea how well these engines could run.

I've yet to see an engine that the 086 doesn't work well in conjunction with, so I would go for that option. It's a top end pipe, but it will give you a massive low to mid range boost over your current setup. Go for the Dynamite hard anodized version as opposed to the Ofna, as its pressure line adapter is in a more ideal location for the Savage's TVP design. It's about $40.

The F4.6 has a high operating pressure so the stinger diameter isn't that big of an issue.

Are you honestly trying to tell me that a wimpy Force 28 engine has a higher operating pressure than a Picco 28 or LRP 28 or Nova Rossi 28XRP, all of which run HORRIBLY on the HPI pipe? Basic physics: Engine torque is directly proportional to the force applied to the crankshaft by the connecting rod. Force on the piston (and subsequently connecting rod) is equal to pressure multiplied by surface area. Because the piston surface area is help constant in this comparison, for your statement to be true, the Force 28 would have to out torque all of the engines listed above at the top of the RPM range, which obviously isn't the case. The F4.6 has a LOWER operating pressure at essentially every RPM range than most .28 engines, and will thus suffer more from the polished pipe's inability to provide backpressure at elevated RPM.

Essentially, the pipe is a piece of crap, and there is no logic in buying it when you can get a 086 for $10 more. Hell, the polished pipe causes even the HPI K5.9 engine to run lean at high RPM, and it has nearly 25% more displacement and similar operating pressures.

 

[JohnH]

This is The last thing I'm going to say before I start Moderating threads. Watch your lip on this forum. You have the right to disagree but watch how you say it. As for me I have over 15 years in this hobby and the combined time in this hobby for the manufacturers and modders that I know and talk to weekly have 100 years in this hobby. Some pipes work with some motors. There isn't a pipe made that works perfect with every motor. Not even the Buku does that. For tooling around the yard the HPI tuned pipe is fine, or even the new tuned pipe for the xl. Done.

 

[romper4444]

First of all the hpi ribbed pipe or polished pipe is not an AMAZING! pipe, never said it was, the loud sound of it does not trick me into thinking my truck is faster, it actually is, its pretty easy to see that if I twitch the throttle a little to much, the thing flips over backwards, my Rammy, will actually pull a wheelie now, as no way in hell it would do it before. maybe if i had two identical trucks side by side and one had an 086 and one had a ribbed, I'd, of course say WOW, that HPI pipe sucks, BUT stick it beside the piece of crap mufffler stocker thats on there, and WOW that HPI pipe is awesome. Point being its a hell of a lot better than what I got, and it was 30 bucks, so If I don;'t like it I'll keep it, no loss, or sell it to the kid next door. FACT is both pipes are 30bucks, they add plenty of extra power, ESPECIALLY ON MY RAMMY, as the stocker sucks, I'n not a racer, so I don't need to get the absolute best pipe for my basher, sure it would be nice, thats why i considered a JP-3 as in my area thats all anyone runs if they're running a high end pipe, nobody runs 086's, so obviously its not going to come to mind, I think I'm going to go with the dynamite/Losi HT polished as its 40 dollars, and i think its definetly the best bang for my buck. i think I'll switch from the ribbed to the polished HPI pipe, as its a nice addition to an allready fast truck, plus the higher temps with the ribbed pipe I don't like either, i'll try it on another truck someday, maybe It'll be a nice addition to that one, whatever it'll be. I can't afford to buy a high end pipe for the 6 bloody nitros I allready have,hard enough to keep them in running tip top as it is. Oh ya and to go as far and say that its a marketing scam or something is ridiculous, if they were I would have put the pipe on, lost half my mileage and wouldn't be able to pull a wheelie anymore, not the case. You can have your opinion as to not liking the pipes, but don't say they're complete crap, cause they are not, you know whats complete crap, that stupid RC supercharger kit, now thats a marketing scam! Peace out, megabytme said it best, DONE!