I have a pair of ITR cams with AEM cam gears installed in my 98 gsr. I was wondering what would be the most optimal degree of advance/retard tuning for the cam gears? Thanks

 

I think a lot of b16 and b18 vtec motors that are mostly stock wind up with a configuration like a gsr I watched on the dyno a few years ago

intake: adv 3 degrees, exh 0 degrees (no change)

things vary so much with what major modifications you have (especially something like big cams or intake manifold, or something much more radically different like boosting)... that 3/0 was with intake/header/exhaust, and made better power than anything from -8/8 to 8/-8...

someone else who maybe has exactly what you have, you'd have a starting point to go from. but even cars that are the 'same' aren't exactly the same. it has to be a unique tune.

good luck

 

I forgot to mention that I also have the skunk2 IM, the edelbrock 65m TB, and 4-1 headers. u still think 3/0 would be good?

I got a obd1 ecu/chipped and a v-afc, any suggestions for tuning them?

 

if you have the v-afc.... that's excellent. you should lower VTEC to about 4000, with a configuration like you have. do you know how to tune with the vafc?

i have no idea what will be good. if I were you, I'd start trying things (making sure, of course, that you reset your ignition timing each time you move the cam gears, with your timing light. on my motor, the intake cam is what the dizzy spins from, and it needs resetting every time. don't know about yours)... i'd try the following: 3/0, 3/6, 6/3, 6/0..... others will tell you to try retarding in some places etc... every time you advance intake and/or retard exhaust (relative to one another), you increase the the overlap of your opened intake/exhaust valves. in some sense, you can take advantage of different properties of air flow physics, and so on, but it probably doesn't work to try to make sense of those things for what you have done. I would test different combinations, mostly advancing things, like the list of advances that I listed, and see what brings you power.

tuning for top end, I would set them, and time how long it takes to go from VTEC to rev limit in 2nd gear (or 3rd + more accurately, but 2nd to stay in speed limits) and so on. that's primitive street tuning. and if you've moved VTEC to 4k or 4500, you'll gain even more accuracy. use a stopwatch, or have a friend help, too. or go tune at an 1/8th mile track. lots of options.

i hope someone can tell you something about how they have their cam gears set, who have similar mods to you. I have no idea where to really tell you you should have them set, other than telling you (like above) how I'd go about it to start with. good luck, and don't forget to lower vtec. I would, anyway.

 

They should only be adjusted on a dyno where the actual gains can be seen. No two engines will react the same to the same modifications, so trying to find something that has worked for someone else might not necessarily work for you.

 

right now my vafc has my vtec kicking in at 4600rpm. is 4000rpm good for low end power or highend power? at what rpm does ur vtec kickin?

 

i see what you mean man thanks. it's just that i don't got the greens to bring my ride to the dyno, so i gots to go wit the ghetto garage style.

 

I would have vtec engaging a little later. I have CTR cams in mine and my vtec engages around 5200 rpms. I wouldn't touch those cam gears, though. Either sell them off or get on a dyno to see if they will benefit you.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Das Schmoo &raquo;</TD></TR><TR><TD CLASS="quote">I would have vtec engaging a little later. I have CTR cams in mine and my vtec engages around 5200 rpms. I wouldn't touch those cam gears, though. Either sell them off or get on a dyno to see if they will benefit you.</TD></TR></TABLE>
why sell them?

 

a quick suggest, if your using itr cams and a aftermarket IM, u should "RAISE" your vtec up to where the itr ususally like their vtec, around 5100-5400 depending on where it feels the best..shmoo's right about the dyno.. but you should tune your cam for each degree you set it, if you advance your intake +1 , tune that whole map, low cam and high cam and then do it again so your not making major adjustments nor hurting anything in the process, also plz remember after making an adjustment like that on cam gears, you yourself should turn the motor Counterclock wise(the way it spins) at two FULL rotations to make sure there's no pistons to valve contact.. if you dont and u crank it right up and crack vtec.. and u hit a valve.. you'll be putting curtains on your new window in your block..

 

He says sell em because.. basically their oem stock cams.. you can't really unlock any hidden power, thats why their good for a mild b16 or b18 build.. advancing the intake by 1 or 2 might help so long much as the motor reving better but thats it..thats just my two cents.. they dont have wicked lopes like skunk2 or crane or toda, or jun or crower they just stock honda cams

 

selling them might be the way to go. if you get good stage 2+ cams they're worth playing with.

since they're basically OEM cams, those guys are more right in terms of advancing only 1 or 2 degrees. like I said, non-race cam builds of b16's and b18's often find combinations of a slight intake advance, and no change in exhaust cam, to unlock a few hp up high, via 3 cam degrees increased overlap (6 degrees crank). if I were you, and wasn't going to sell them, I'd try 3/0, and if that works, I wouldn't touch them other than that. or 2/0 if you want. the overlap will be taken some advantage of, since you have the manifold...

i'd play with VTEC. your IM and cams act different than a normal gsr setup. I've never heard of it doing better moved up. If you can flow more air via the IM and other bolt ons, you can take advantage of the increased duration at a lower RPM. It's the same concept of not taking advantage of more high lift/dur cams without having other things done (like head port, IM, etc etc)... what little you have done might make a small difference. if I were you I'd try VTEC at 4000, and you'll either notice a huge drop in power from 4-5k, or a huge increase in power. If power increases, then keep it. If it bogs on VTEC crossover (which I wouldn't predict, as I've seen lots of vtec controllers finding great success lowering VTEC), then raise VTEC a few hundred RPMs, as IntegraType-R is saying.

I'm sure, however, that what little extra air you can flow would only take advantage of the greater cam duration at a _lower_ RPM. As you raise it, you're trying to flow the same amount of air with the low end cam lobes at a higher RPM. That's exactly opposite what you want to do to increase performance. it's easy to play with, anyway. don't be afraid to play with it. Some people set it to 3500.

good luck