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GRP 28 or OS 28

GRP 28 or OS 28

Old 09-10-2008, 02:10 PM
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Default GRP 28 or OS 28

I will be purchasing a new 28 engine for my 8ight T soon. LHS has a tuned GRP 28 with pipe and an OS 28 with Jammin pipe. Only $20 difference between the two. What are the pros and cons of the two? Things I am considering are tuneability, fuel mileage, performance, and longevity. I am Currently running an OS 21 VSPEC in my buggy and I love it. Can you use the same glow plugs in the GRP and the OS?

Thanks
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Old 09-10-2008, 02:13 PM
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Go with the OS for sure!!! Trust me dude
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Old 09-10-2008, 02:36 PM
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id say the GRp over the OS....smoother power band and better run times. ...and if u want Killer power out of the GRP dont buy the Promo pack....get Just the motor and pair it up with a MSR 1005 or the 1001 with re-enforced stinger.
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Old 09-10-2008, 03:06 PM
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Well, that's one for each. So far doesn't make the descision easier!
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Old 09-10-2008, 03:30 PM
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You can't really go wrong with either motor. I've driven both and own an O.S. My experience has been that the O.S. is substantially easier to tune. I don't know what the run time is like with the GRP, so I can't help there. My O.S. will get 8 minutes per tank on average although when I ease up a little bit, I've gotten as much as 11. I've run it with a 7mm restrictor 90% of the time, with the other 10% being a 6.5mm. Tons of power with either size though. I've been using the T2050 pipe, .95mm clutch springs, aluminum shoes, usually 13t clutch bell and 48t spur on my ST-RR(50t is stock). As far as the glowplugs, I've been using P3's with success. The GRP I tried would bubble from around the glowplug when an O.S. plug was used. From what I've read on the GRP thread, that sounds common.
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Old 09-10-2008, 05:49 PM
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i run the ninja .28 with a bullit 1005 pipe and it is an insane combination! i can tell you that the internals on grp engines are all superior to o.s. engines. i have nothing against o.s. engines as they make big power, but they just don't last from my experience. i have owned numerous grp engines and can say that they are nice to tune. just pop in a grp #4 plug and tuning is very easy. i do know that they like a "more lean" bottom end than most engines. btw, the top end is especially crazy when combining a grp.28 or .21 and the bullit 1005 pipe.
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Old 09-10-2008, 11:11 PM
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I would go with the OS 28
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Old 09-10-2008, 11:22 PM
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another very nice mill is the new Nova 28-7T !
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Old 09-11-2008, 08:02 AM
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I am really tempted to go with the GRP. The only thing that holds me back is my .21 EB Mods OS runs so well. Even tried it in the truggy and it seems if that is enough power for it. Don't know if I need the extra power of a .28. What are most of the fast guys running, .21 or .28? I am going to try my .21 in my tryggy at the track this weekend and see how that works. Might wait till after the worlds next week to see if anything new is on the horizon before I buy anything. Thanks for all your input.

J
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Old 09-11-2008, 09:36 AM
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Don't know if I need the extra power of a .28. What are most of the fast guys running, .21 or .28?
Most are running .21's which will certainly get the job done. In my opinion, it all comes down to your experience and throttle control. For quite some time, I put off getting a .28 because nearly everyone on these forums makes it sound like they're undrivable, just way too much power. I finally came across a deal on one I couldn't pass up so I tried it. I'm really glad I did. The last time I compared times between two 5 minute qualifiers in the same day, one with a .21, the other with the .28, I was 9 seconds faster with the .28. I also believe that you can clutch the .28 with smaller springs to tame it down a little bit. It's still gonna have stronger bottom end than a .21 though. Just my .02.
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Old 09-11-2008, 01:51 PM
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nobody in my area runs a 28 in their RC8T or losi 8T. if you had a heavier truck then maybe.
but in a losi? run a .21
Get yourself another vspec. like an ebmods or speed. the few 8t's with ebmods vspec's are stupid fast running os2050, os2060, jp3 or jp4 most use the maxlife shoes.
I think the springs are 2 black 2 gold. Not 100% on that though.

good luck
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Old 09-11-2008, 02:01 PM
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Tried the .21 ebmods vspec in 8T today and it worked pretty darn good. Ran a long time on a tank of fuel, didn't time it though. I think if I play with the clutch a little I should get her dialed. Running Losi long wear with 4 gold springs. Might go the .21 route for now. Still have to decide if its gonna be a GRP or OS.
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Old 09-11-2008, 02:43 PM
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+1 on OS 28. I do have that EBmod .21 vspec also.
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