grp .21 fuel consumption

[jshbetz11]

I have a rossi tuned grp .21 on my 2.o buggy. It is ran with a grp 2653 pipe and manifold. I usually run a p3 plug. Is this engine pipe combo just not known for good gas consumption? Im getting bout 8 min. per tank at 175F with running a p5 plug. With the p3 probally about 6 minutes. Is there a better pipe to run with this engine? Track layout is somewhat technical so only wide open on straight but that is for only like 2 seconds. My driving style is not grip n rip so what can i do? Am currently running Odonnel's 30%, that helped a little over the Trinity platnium 30%. Also running the smallest carb insert think it's 6mm

[Neobart]

That is very odd, they are known for good fuel economy. I run mine with a RE11 pipe and GRP c5 plugs, and get 9-11 minutes depending on the track.

[jshbetz11]

think the pipe is actually 2853 hard to read. Everybody runs ur pipe at thee track think im gonna give it a try. I have a **** of a time trytin to find grp plugs ever run p3-p5? How is the fuel consumption compared to the grp plugs?

[Neobart]

Don't know about the OS plugs, you should try a Picco p5th plug instead. You can risk getting leaks around the plugs running OS plugs. They have a slightly different taper than GRP and Picco plugs.

[LVBaja]

The best pipe I've found for the GRP tuned 21 is the pipe that came with the promo kit. It's an EFRA 2053 (see link below). With 30% nitro fuel, an OS P3 plug, a 6mm restrictor, a good tune and conservative throttle finger, I can go 12+ minutes on a 125cc tank.

http://www.horizonhobby.com/Products/Default.aspx?ProdID=LOSR2049

If yours is temping at 175, it's probably a bit on the rich side. Lean it out a bit more and your fuel economy will improve. Just don't get too lean on the top. They like being a little rich on top.

You may also want to check your clutch out. If the clutch is not working properly (engaging too early or bad clutch bearings or gear mesh), this can have an effect on the run time also.

[hdcruzer]

At 175 your way rich. You should be runnin about 220-240, maybe a little hotter depending on conditions. Id start by leaning about 2 hrs on bottom and go from there. Top is where you can gage your temp if you run wot a lot. Gets to hot over 250 say, richen the top an hour at a time until you reach your disired temp.

[LVBaja]

At 175 your way rich. You should be runnin about 220-240, maybe a little hotter depending on conditions. Id start by leaning about 2 hrs on bottom and go from there. Top is where you can gage your temp if you run wot a lot. Gets to hot over 250 say, richen the top an hour at a time until you reach your disired temp.

Is that where your GRP likes to run? That seems a bit hotter than I've experienced. Experienced tuners will tell you not to tune to temps, but only use them as a guideline to determine if you're in the ballpark. I've always heard that the GRP's run somewhere in the high 190's to low 200's when they're tuned correctly, but if you tune to sound, performance, smoke, etc., you'll probably end up running within this temp range.

[jshbetz11]

At 175 your way rich. You should be runnin about 220-240, maybe a little hotter depending on conditions. Id start by leaning about 2 hrs on bottom and go from there. Top is where you can gage your temp if you run wot a lot. Gets to hot over 250 say, richen the top an hour at a time until you reach your disired temp.

there's no way I'm runnin a grp over 200F. Yes I do usually run a p3 tried the p5 liked it. The pipe is a grp was the promo pipe with the quick disconnect. guess I just gotta lean her out a tad more. I've found my mill likes to be lil fat on the bottom rather the top. Too lean on the bottom she hangs when dropping back to idle. I have the hard anadized (sp) version rather that the polished. Thanks for the help guys

[Errorhead]

there's no way I'm runnin a grp over 200F. Yes I do usually run a p3 tried the p5 liked it. The pipe is a grp was the promo pipe with the quick disconnect. guess I just gotta lean her out a tad more. I've found my mill likes to be lil fat on the bottom rather the top. Too lean on the bottom she hangs when dropping back to idle. I have the hard anadized (sp) version rather that the polished. Thanks for the help guys

My mess don't even come to life till about 225 and won't have any get up and go till about 200. 220-250 ain't going to hurt anything as long as you got a good smoke trail.

[hdcruzer]

Is that where your GRP likes to run? That seems a bit hotter than I've experienced. Experienced tuners will tell you not to tune to temps, but only use them as a guideline to determine if you're in the ballpark. I've always heard that the GRP's run somewhere in the high 190's to low 200's when they're tuned correctly, but if you tune to sound, performance, smoke, etc., you'll probably end up running within this temp range. I dont run a GRP, I run a losi 454, but alot of the guys I run with run GRPS both .21 and .28s the guys rinning the 21s all run between 220 and 240 and the guys running the 28s run about like my losi at 230 to 260. and this is in 100 degree heat. With the weather cooling down to high 60s and low 70s my losi runs at about 180 to 200.

[Clint Wachter]

I ran GRP for over a year and I can tell you that 260 is way to hot for the .21. In certain conditions mine ran at 220 but it never got any hotter than that. The way the head is the temp gun doesn't get close to the glow plug which is why the temps are so cool. I would try a colder plug. Maybe a P5 or P6. The 2053 is a perfect pipe for this engine also. You should be able to get around 9+ min. at any track you go to with this set up.

[jshbetz11]

ya definetly not goin past 210f coupled with the fact they don't make em anymore. I really like the mill seems crazy fast at the carb setting now can't imagine leaning her out anymore. Might give a p6 a try see what happens. Almost hangs with my friends eb mods v-spec, but that mills kills me in fuel consumption. Indoor season starts soon so that will mean retune so maybe get better fuel economy with the p6 but lovin the p5 better than the p3.

[323 Racin]

I run a GRP .21 on my 8T 2.0 with a 7mm restrictor, a losi clutch setup and a old 053 Ofna pipe. It make great power across all ranges and runs 190 to 195 most of the time. I avg. 10.5 mins. per tank and that pushing it hard petty hard ( i get white knunkle fever at race time)

[LVBaja]

I run a GRP .21 on my 8T 2.0 with a 7mm restrictor, a losi clutch setup and a old 053 Ofna pipe. It make great power across all ranges and runs 190 to 195 most of the time. I avg. 10.5 mins. per tank and that pushing it hard petty hard ( i get white knunkle fever at race time)

Yup, that sounds about right for the GRP.