PRP Swift

[CorradoPsi]

Sorry, it's been very busy at work cause we are re-locating to a new site. I'll get the information to you by next week. Everything at work is a mess cause there's computer's everywhere, boxes, boxes, and more boxes. I'm posting from home right now. We should be live ( internet friday ( june25 ). Sorry for the delay.



Here ya go. I remember posting it a long time ago, but there are the part numbers for the different shim kits.

As for the copper shim, I just used an RB concept copper shim for a .21.

thanks HP, thats all i needed for now, ill call my LHS tomorrow to order up those shims awhile.

since my car will be in pieces as i wait for those parts to come in. ill send the outdrives out for treatment. i know the one guy who works at PRP is on here, is there anyway he can chime in and tell me if the steel is just regular mild steel (cold or hot rolled), or if its a spring steel alloy. this info isnt necessary for me to procede but it would help to insure the success of what I'm trying to do. it could help everyone including PRP if it works out.

 

[niggle]

Re: SH engine overheating

I have noticed that the SH engine appears to be very sensitive to fuel line (tank) pressure.

If I tune for mid-tank pressure, the engine gets on the pipe and head temperature can be controlled around 240F, but with the same HSN setting at full tank it is too rich to get on the pipe and with a nearly empty tank temperatures shoot to over 280F.

The venturi design on the carb doesn't look too great, I'm guessing that at WOT there is not enough depression to suck the fuel out of the HSN jet and the engine is really relying on tank pressure to force enough fuel through. When fuel tank/line pressure drops off as the tank nears empty it starts to run too weak and overheats.

At first I thought I had an air leak so I rebuilt the engine. I used ultra-copper RTV to seal the carb neck and back-plate and sealed the LSN threads with PTFE tape. The engine starts and idles OK but the air/fuel mixture is still varying greatly from full-tank to empty-tank.

I've started a thread in the "nitro engines" forum in the R/C Mechanics section as this problem is not necessarily unique to the Swift, so please follow up there.

I've got a Hyper .21 8-port and 086 inline pipe on order for my main car so I'm not too worried, but this means that the T-car will have 2 hardly used SH engines available and I'd like to get to the bottom of this problem.

I've also been using a NovaMega (NovaRossi) "special" #6 plug and this has made the engine much more snappy. It does have a tendency to stall on a very cold engine with this plug but the performance when properly warmed up is much improved.

 

[WA2FAST]

Yeah niggle, I've been saying this all along. I have just gotten kind of used to it. This is exactly what makes tuning this motor very difficult. As you tune it and are making the adjustments to the HSN and LSN and get your temps where you want them with acceptable performance, as soon as you have a full tank, it's rich as hell again. I have taken it down to factory settings numerous times to work this out, but it doesn't matter. I have given in and have it set so that my first tank usually seems to run rvery rich and slow, but as soon as the tank starts to empty performance starts to go up and the engine starts to run good... then from them on, I can refill the tank and it will act just the same. I know that most people will say check for air leaks, but I'm telling you... it's just the way this motor is. Even when I kill the engine and work on it, fire it back up... it runs strong still even after cooling completely. It seems that when it sits overnight and you go to run it again, plan on the first 3/4 of the first tank being slow and rich, but after that, it's fine. I've just kind of learned to deal with it till I get my new motor.

On a side note... I ripped a pivot ball out of the socket this weekend... Roger, did you say that there is an "old style" that has brass inside the cup or something that works better? It was a pretty good crash, but didn't seem hard enough to do what it did... I wouldn't expect the ball to rip out on what I did to it.

 

[niggle]

You seem to be in a better position than me, as only the first 3/4 tank is rich for you. After using 1/4 gallon yesterday I tuned for a nearly empty tank and then filled up again. It was so rich that the motor was 4-stroking at WOT until the tank half emptied.

 

[WA2FAST]

Wow... mine is not that bad... it took me a while to get it where it is now though, I can tell you that. It's managable now though... as soon as I get it started, I just keep on it through 3/4 of the first tank and it is fine after that.

 

[CorradoPsi]

wouldnt a new carb, with a 3rd needle, fix all this? since you can put the venturi where you want it, so it pulls proper vaccuum on it.

 

[niggle]

wouldnt a new carb, with a 3rd needle, fix all this? since you can put the venturi where you want it, so it pulls proper vaccuum on it.

3 needle carbs are rare beasts and I suspect that if you could find a supplier for one in the UK it would not be much cheaper than a new engine from a different manufacturer.

Cost issues aside, I don't see how a 3rd needle/jet assembly is going to change the venturi profile in the carb throat. Please enlighten us.

If you change the carb then the SH engine's suspected poor venturi design is obviated and thus it's irrelevant whether you replace it with a 2-needle or 3-needle carb.

 

[CorradoPsi]

well i asked about the carb because i have a 3 needle ofna here i can use. a 3rd needle wont change the profile of the inlet to the carb. but it will allow you to adjust how much of the jet is in the venturi, to achieve better airflow over it and create the proper vacuum to pull fuel through it. you could also pull your carb apart and use a dremel tool to change the shape of the inlet if you want. I've seen this done before, and its legal so long as you dont change the diameter as it goes through where the slide is. just shape it from the mouth of the carb to the slide.

heres a how to, on what I'm talking about.

and if you look here you will see what i mean about moving the jet (3rd needle) if you change carbs. the jet is on the left and low speed needle the right. if you move the jet around you can put it in a better place to pull more vacuum through it.

 

[niggle]

and if you look here you will see what i mean about moving the jet (3rd needle) if you change carbs. the jet is on the left and low speed needle the right. if you move the jet around you can put it in a better place to pull more vacuum through it.

Now I understand, thanks for that.

It's not a 3rd/middle needle as such, just a means of positioning the opening of the main jet. This is great if you have decent air speed/depression somewhere in the carb throat.

With the SH engine it could be that the venturi diameter is just too big to give any decent depression at WOT. This engine is never going to make fantastic power anyway so a smaller venturi would probably be better.

RB Concepts use 2 needle carbs but supply carb throat restrictors to reduce fuel consumption and improve low/mid response.

 

[WA2FAST]

Either way, I am getting my WS7II very soon anyway... never heard anything bad about that motor, especially tuning is very easy and consistant on it from what I hear too.

 

[niggle]

Either way, I am getting my WS7II very soon anyway... never heard anything bad about that motor, especially tuning is very easy and consistant on it from what I hear too.

It's the choice of (UK) champions! It probably has more top end power than you will ever need so go for an 063 inline tuned pipe to fatten up the low- and mid-range power.

 

[WA2FAST]

That seems to be the killer combo from what I hear as far as the pipe is concerned... sounds like a winning match to me

 

[WA2FAST]

I picked up a whole slew of parts from my LHS for the car, so I should be in good shape... noticed that the pivot ball sockets for the suspension up front DO have the brass threads inside of them. I assume that these are the "old style"... and I beleive that I heard from someone that they were better? Is this right?

Also, I noticed that the pins on the bone side of the CVJ where they go into the outdrives... they are worn to hell... grooved so bad that the pins are almost sheered clean off. You can NOT see the wear unless you take the bone OUT of the outdrive and look at the pins from the side, not the end. Is this because of the way the soft outdrives wear, or are the pins even softer than the outdrives? Is this a continuation of the outdrive problem, or is this another problem in itself? Has anyone really looked close enough to look? I didn't notice till I went through the diffs last time... looking at them when everything is together, you can't tell... but when I pulled the diff's out and looked at them closely, the cross pin on the bone side is almost completely sheered off.

Jose, how are these on your car? Roger... have you heard of this yet? I bought a couple of extras just in case to replace any worn CVJ's (I sheered the ball joint clean off of the bone this weekend), but it is nice to know that you can buy JUST the bone side for half the price. Anyone have this problem???

 

[xxxzayas]

WA2FAST: The majority of the wear on the bones is due to the outdrives. Keep in mind even if the outdrives were hardened you will still see the pin wear on the driveshaft. This happens on all cars and is primarily due to braking. I hope this helps.

Jose

 

[Gixer Jay]

Also, I noticed that the pins on the bone side of the CVJ where they go into the outdrives... they are worn to hell... grooved so bad that the pins are almost sheered clean off. You can NOT see the wear unless you take the bone OUT of the outdrive and look at the pins from the side, not the end.

I told ya bro..

Don.. MBX5..

This tells all..




2004 Michigan Gas Racers Point Series

8th scale
Race 1 Race2 Race3 Race4 Race5 Total Name
102 102 204 Gixer Jay
96 96 192 Nikia Maxwell
100 91 191 Dale Mckenzie
94 94 188 Mini Joe
95 87 182 Bill Sutton
98 82 180 Jesse Ramey
91 88 179 Greg Ward
84 93 177 Chris Haenlein
78 98 176 Brian Goyette
82 92 174 Jon Countegan
92 79 171 Sterling Buckley
85 83 168 Kirk Robinson
88 77 165 Bob Sutton
83 81 164 Brian Kozlowski
89 74 163 Greg Newsome
93 69 162 John Smith
90 71 161 Joe Rau
79 78 157 Gary Hitchcock
87 68 155 Johb Oquin
81 73 154 Allan Bradly
75 70 145 Steve Suriano
100tq 0 100 Don Elliott
0 100 100 Chico Alvarado
0 100tq 100 Jay Mowl
97 0 97 Chuck Fobare
0 97 97 Doug Davis
0 95 95 Mike George
0 90 90 Noah Hampton
0 89 89 Jeremy Schmiege
0 86 86 Corey Cheney
0 86 86 Mark Matthews
0 85 85 Bill Hall
0 84 84 Jack Hughes
0 80 80 Mark Hess
80 0 80 Filix Cantn
77 0 77 Robert Garner
76 0 76 Joe Basilico
0 76 76 David Joseph
0 75 75 Josh Garchow
74 0 74 Steve Kozlowski
0 72 72 Al Hardy
0 69 69 Eric Flowers

 

[niggle]

Also, I noticed that the pins on the bone side of the CVJ where they go into the outdrives... they are worn to hell... grooved so bad that the pins are almost sheered clean off. You can NOT see the wear unless you take the bone OUT of the outdrive and look at the pins from the side, not the end. Is this because of the way the soft outdrives wear, or are the pins even softer than the outdrives? Is this a continuation of the outdrive problem, or is this another problem in itself? Has anyone really looked close enough to look? I didn't notice till I went through the diffs last time... looking at them when everything is together, you can't tell... but when I pulled the diff's out and looked at them closely, the cross pin on the bone side is almost completely sheered off.

My T-car is completely stripped down now and the dogbone drive pins are as you have described.

I'm assuming that the dogbone pins are a press fit, in which case I am going to punch them out and fit 3mm spring steel roll pins instead.

 

[Savage_SAVAGE]

:shrug:
So............... what's a "T-Car" then??? I know for a fact you should have a perfect hardly used set of dog bones.................
Have you got both cars running now?

Got to say, there do seem to be a lot of "poor quality material" issues with these Swift buggies, glad I haven't got one! :jk:

You didn't think you'd get rid of me that easily did you?????

If it's any consolation, my Savage has eaten 3 diffs and a gearbox so far.......

Might be something to do with the brutal .46 engine though?! :devious:

 

[niggle]

So............... what's a "T-Car" then??? I know for a fact you should have a perfect hardly used set of dog bones.................
Have you got both cars running now?

T-car = spare car. Like the 3rd car the F1 boys hop into when they've piled into the armco on the formation lap.

Surprisingly, the dogbones and outdrives on your old car are in worse shape than on my original car - and that's had a gallon through it now. Obviously not your fault - just the variance in production quality at the factory.

I stripped it down completely for cleaning/inspection and also whilst I got confirmation of UK parts prices.

I've just got a retail price list from Robin Schumacher and the prices are actually quite reasonable, not strictly to the 1.80 dollar/pound exchange rate but not far off.

I've got signoff from the financial director and I haven't broken anything else on the main car so the rebuild can go ahead - it might even get a Hyper 8-port and inline pipe set.

 

[CorradoPsi]

first day out

ok so I'm through idling tanks and I'm out running the car now. handles ok i guess, good for an offroad vehicle, guess I'm just used to my onroad cars. anyway

has anyone broken thier front brace yet. the carbon fiber one that attaches to the front bulkhead. i managed to today in the first 10 minutes and I'm not even sure of how, cause i wasn't running it hard. i cartwheeled it about 3 times in some really rutted mulch but thats all i can think of. still finishing up the breakin so i didnt even have it up to speed, maybe 15mph if that. has anyone found an aluminum part from another buggy that fits? otherwise I'm stuck making my own from aluminum. i can do it, but id rather just buy the part. and i dont want another carbon fiber piece if they break this easy :nono:

i also managed to trash the wing pretty good too, damn.

 

[WA2FAST]

WA2FAST: The majority of the wear on the bones is due to the outdrives. Keep in mind even if the outdrives were hardened you will still see the pin wear on the driveshaft. This happens on all cars and is primarily due to braking. I hope this helps.

Jose

You are very right Jose... the bones will wear regardless, but what I can tell you is that out of the 6 bones that came from the factory on this car... 5 of them have the "shiny, chrome" pins through them... one has a very dull steel pin in it. The dull one is completely gouged out and the pin on either side of the bone are almost completely gone. The others are holding up MUCH better. Wonder why I got the poop end of the stick with getting 1 bunk bone. Oh well... either way, I have bought replacements and things seem to be holding up MUCH better now. The other pins are wearing normally just as any other bone would on any other car... I honestly think it has to do with the outdrives more than anything... also that one bone... super soft pin. Don't know what the hell they were thinking there. I will snag a pic of it later and show you what I mean.

Jay... damn man, you are totally dominating that series... I'm really sorry I didn't get everything done in time to be entered in it, really sucks. Anyway, kick ass job man, keep up the good work. Maybe I'll meet you up at the next race and watch you school everyone.

Niggle, I'm willing to bet that if you look at the bone ends on SAVAGE's old car you'd see the dull steel color pins I am talking about, and yes, they look pressed in. I wish I had your resources sometimes for stuff like that.

Savage, the material issues that they have been having is strictly due to the vendors for PRP's factory in their defense... but you are right, these issues should definitely have been worked out before released. In Roger and Cameron's defense... they are doing all that they can at this point in time and trust me, they are working hard on getting these issues resolved... just wish that they have better luck with how long it is taking some times.

ok so I'm through idling tanks and I'm out running the car now. handles ok i guess, good for an offroad vehicle, guess I'm just used to my onroad cars. anyway

has anyone broken thier front brace yet. the carbon fiber one that attaches to the front bulkhead. i managed to today in the first 10 minutes and I'm not even sure of how, cause i wasn't running it hard. i cartwheeled it about 3 times in some really rutted mulch but thats all i can think of. still finishing up the breakin so i didnt even have it up to speed, maybe 15mph if that. has anyone found an aluminum part from another buggy that fits? otherwise I'm stuck making my own from aluminum. i can do it, but id rather just buy the part. and i dont want another carbon fiber piece if they break this easy :nono:

i also managed to trash the wing pretty good too, damn.

Damn man... I have cartwheeled, flipped, spun, crashed this thing the wrong way a million times and have never broken that part... a TON faster than 15mph too. The worst I have done is one time I sheered a bone right off of the CVJ ball, and the second that takes the cake was when I ripped the lower a-arm off, bending the hinge pin real bad, ripping the shock shaft clean out of the shock body, and ripping a pivot ball out of the cup... but none of which couldn't have been fixed right there. I had all above but the bone fixed (2 seperate spills) right there on the spot in minimal time.