br8crumb

just seeing whos out there with a similar setup

basically running a b18c5 iv just about blown up, have a spare b18c5 i picked up last week, and i already rebuilt a gsr head. has all brian crower valve train + pnp/5 angle valve job.

any thoughts on just rebuilding the spare c5 block to oem spec, bolting on the gsr head with the type r cams, and just running a skunk2 manifold at 68/70mm?

will get a slight compression bump to 11ish by using the gsr head which is cool but curious how the torque/whp #s will look compared to just running the c5 head with same manifold/tb/cams. really the only difference would be the chamber on gsr head smaller then type r which gives the compression bump.

mayfly

i would run it. the gsr heads slightly outflow a stock b16. and you have a pnp gsr, so that should outflow the itr.

br8crumb

not too concerned on outflowing the itr head. just gonna enjoy the compression bump and see if #s go up when it goes on the dyno in a few more weeks. if all fails thats 2 complete c5s i have to play with/rebuild lol.

ChrisCoupe1

Haven't ever seen one done in person but heard of one once..was said to be basically equal in feel to a true jdm 99+ itr in power...so sounds pretty fun imo

JRCivic1

I like the combination a lot personally... I currently have a USDM B18C5 block, sleeved with 84mm 11.5:1 JE pistons with a 4Piston P72 head and BC stage 2 cams making 223 wheel HP on pump gas.

Also, long before the "K" series engine became the powerplant of choice in the Honda/Acura FWD All-Motor class, the fastest "B" series cars (like Erik's Racing) were using the GSR (P72) head casting. Coincidence ???

93egSLEEPER

GSR and B16 head flow is a moot point IMO. They both outflow each other in different areas (nothing to scream about) and when all things considered, are pretty much equal. The GSR head will bump the compression a small bit but thats about the only advantage in stock form.

wunfstgsr

Exacly, you wouldnt even feel or tell the diffrence if you litlerlly swapped heads and tuned it, its a great combination, iv used it many times, i used a gsr block but ITR internals and the engines always made great power my fav was one that made 216 WHP with a mild setup using budyy club 3+ cams. Gsr head had flat valves to increase comp further.

J.Berta

This is the difference my itr engine had with itr head vs gsr head. Same itr cams/ just different head and both had 1st Gen skunk2 manifolds. Blue line is gsr head. Red line is itr head.

B20VtecVillain

Your dyno above pretty much sums up what I was going to say from my experience. Currently running a stock JDM B18c shortblock (P73)
With a JDM GSR (P72-1) head and 98+ DC2R cams/valvetrain and it makes a bit more TQ than it did when it was all B18C-R including the PR3 head, but HP stayed about the same. I also notice, though this could be purely mental, that it feels that with the GSR head I have more pull through the mid range and into upper rev range but falls off a bit before fuel cut, whereas I remember the all DC2R setup having a little less mid range pull but it pulled harder right up until fuel cut. Everything else in my build has been equal between the two heads; same header, intake, exhaust, ecu (S300), cams, etc. The only reason I did the change personally was because someone offered me the clean bare GSR head plus a decent amount of cash in exchange for my bare DC2R head for a build he was doing, so I took the deal and made out in my opinion. P72 head has mild port smoothing done by hand but no CNC work and uses OEM valves.

Stopsign32v

iTrader: (1)

That difference could have been from dynoing at different times.

93egSLEEPER

That difference it moot point. The GSR has more power through the entire power band aside from the very peak. It will be nearly identical in performance down a track.

raverx3m

iTrader: (1)

my question is what about timing and detonation

besides almost identical flow
gsr has different quench area
higher intake runner angle
no port and polish
the above chart is b16 vs gsr flow
I cant find type-r vs non type-r head flow anywhere

I'm interested if anyone is running this on a stock type-r obd2 ecu without any issues?

B20VtecVillain

The port job on a Type R head is negligible as far as most port jobs go, and as was said above the difference in flow between all B series VtEC heads is not that big anyway. I have personally run a JDM B18C-R shortblock with a stock JDM P72-1 head and a JDM P73 ecu with good results. The only reason i changed it was when I finally tuned the setup on Hondata. The P73 was actually a decent map.