Go for a spec

Too late, GRP arrived yesterday, guess I could ask for a refund and send it back.

OK, I found a super deal on a vspec, I'll get to find out myself which is better not only did I find the engine, but I have 3 pipes to try on my GRP, a JP-1, a JP-3 and an OS2050

One guy at the local track had a problem with his GRP. Some internal part, can't remember what it was, but it seperated inside, pulled apart. He called them up and they said that it's impossible to kill their engines, so it must have been an unfortunate defect. Sent a replacement.

metal quality and build quality is far superiror on the GRP..... I have several OS motors, they are nice but they are not built as well as the GRP's....... Under harsh conditions I would expect the GRP to have double the lifespan of the V-Spec............. As well the GRP engines are identical tothe older GRP NInja's, they are not hard to tune in any way...they are excelent motors and IMHO a better engine then a V-Spec...a V-Spec may have a slight power advantage but other then that the GRP is the better motor....... I have seen way too many V-Specs meet an early grave for my tastes....

grp hold tune for me dont know why everone else has problem with it i may have to richen like 1hr as night falls but other then that perfect best motor will eat a vspec up if u tune it right

I told myself this when considering both, would you rather have a Ferarri or an Infinity/Lexus. Italians are know for fine craftsmanship, Japenese for excellent quality control in mass production. Both excellent at what they do.

i know of 2 people who have had there carbs stick

Yeah, I've heard that Vspec have been having carb problems

My tuned .21 GRP tunes as well as any engine I've ever run, and just as reliable - Again, I've no idea why people are struggling so much with tuning them. I've also tuned 3 individual engines, and not one of those 3 GRP's have been a pain.

As a whole the GRP is very smooth, powerful throughout the powerband but really consistent and predictable to drive with - Awesome motor.

this one is easy..I have had both and the GRP is far stronger, better built, and has more power then the vspec. Not to mention the build quality is far superior imo (not that the vspec is a bad mill..it is great, but not in the same league as the GRP). I am not sure what the deal is with flameouts...mine never did, nor has any of them at the tracks I run at (flame out). The GRP needs to be tuned with the LSN, then the HSN..the LSN is crucial...it likes to be a little leaner then some other engines....tune that first, then tune the HSN and you should be screaming with good smoke, 200 degree temps, and 10 minute runtimes (pretty easily I might add). If it is flameing out your LSN is likely too rich. Also, go to a GRP 4 plug...it opens the tuning window a bit and the temps seem to be a little lower

All I can say is, the GRP got so much attention due to a lot of US drivers using them. At our local track, the OS is the choice to use. Very few use the GRP and even at that, I have seen some have issues with it and it hasn't had any performance to write home about

If I wanted an italian mill, Novarossi would have been my choice. GRP & Axe Rossi are family member spinoffs, but they have some engine goods traits in their engine building IMO. GRP just got on to a bigger distrubutor than Axe Rossi did. But at least Axe Rossi brought a EUROs title to their brand name.

there is also the mugen ninja JX.21
a mix of best of Italy and OS ??

The new ninja is an OS motor built to Ninja specs. It's a .28 block with a DLC coated crank... oh and it's a 5 port motor not 3. I've heard lots of good things about it.

i have both
os on off switch
grp smother
speed bout the same

there both nice

id like to try a os speed i hear there cool.