Bigger T/B worth it?

[m0nty]

If you're going down the path of drag/street I'd be thinking about ITBs. Have you already bought and fitted the RBC? Combined cost with a 70mm TB isn't far off what you can get some ITB setups for.

[03DC5R]

yeh i've already bought the rbc...im sticking with my stock t/b, and later on when i build my bottom end (maybe k20/24) i'll do ITB's

[DrTran]

ITB's sound great when you hit vtec

[noodleman]

but with itb you will lose alot of power if you strap filters on

[DrTran]

yea you will lose power but if your running at the track more than likely your probably not going to run filters

[noodleman]

i would run filters on the track instead...cos if you spin out means alot of dust will end up inside the engine

[DrTran]

dust really isn't a problem i'd be more worried about rocks and pebbles

[Absolut R]

wont going with too bigger cams make you almost loose vtec? as in the lobes that surround the vtec lobe are the only ones that increase in size?? so the transition into vtec is smaller kinda killing vtec? i dunno i still would want that burst into vtec if this is in fact the case.. spec b's ftw.. if your increasing the manifold that can bore to match a larger TB why not get it.. if not the 70mm even the 68mm?

[air23box]

I've got mine custom bored to 68mm......didn't notice any different in low revs.....but for sure top end pull a lot harder........help me to improve my lap time approx 1/2 sec compare stock.......
or maybe I am not good enough to feel the difference??.....lol......or maybe K20 have better low end torque?

[03DC5R]

made the decision to stick with the stock t/b for now till i start on the bottom end next year sometime...i'd rather get the clutch/fly for now as i will feel this alot more than the t/b with stock clutch/fly. should be getting all the stuff put in early december...cant wait to see what it doea on wsid

[TODA AU]

itb will made the idle alot worst then bigger tb

Only when they are installed & tuned by someone who doesn't really know what they are doing. The problem could be in the set up & how much the installer really knew, or it could be a tune issue. Either way, they should idle fine & they can be made to.
Idle should generally be better than plenum system, particularly when large cams are employed.

but with itb you will lose alot of power if you strap filters on

You should be using an airbox with CAI feed & remote filter.
Omitting this part will cost you power & response.
If you've got ITB's & are having issues we can probably sort them out for you.
If the budget cannot be streched to install ITB's with all required ascociated hardware, you are much better of staying with a plenum system intake.
Both power wise & finacially.

wont going with too bigger cams make you almost loose vtec? as in the lobes that surround the vtec lobe are the only ones that increase in size?? so the transition into vtec is smaller kinda killing vtec? i dunno i still would want that burst into vtec if this is in fact the case.. spec b's ftw.. if your increasing the manifold that can bore to match a larger TB why not get it.. if not the 70mm even the 68mm?

Depending on cam manufacturer will determine the amount of change from stock in the low & the high cam lobes.
Generally for best power delivery, the transition from low cam to high (Vtec swap) is smooth (almost undetectable) at best.
A sudden burst of power when you hit Vtec, means you're probably missing out on power earlier in the rev range where you could have swapped earlier.
Of course this isn't always the case & again depends on the cam manufuactuer (& to a lesser extent the installer & tuner.)
Regarding larger throttles,
Though popular with salesmen, these are less popular with engine builders & tuners & really aught to be well & truley late in your agenda.
Why? Well in reallity on a standard compression DOHC Vtec engine. There is very little if anything to be gained by changing to a larger throttle.
Further, it aught to be noted many engines actually go backwards.
In my experience, engines with standard compression & cams gain very little & generally go backwards when you go this way.
Most of the time but not always, this power loss can be tuned back into it, but the net result is a waste of time & money.
Before you buy a throttle, look at the obvious mods 1st.
CAI, Good header, Good exhaust, ECU, cams, compression etc...
If all that's covered & it's a high output built engine,
Talk to your engine builder & or tuner (Not a parts salesman or racer) & workout what you need.
Don't just guess, ask someone with real experience & get it right 1st time.
Hope that helps.

[benson]

My best advice is to sign up on www.k20a.org and do your research on that forum. They are the biggest forum for K-series talk and know the pro and cons of every modification.

Learn from people that have real experience from different products and combo's that actually really works. You'll be amaze from certain results

[03DC5R]

i did my search on clubrsx as well, and the majority dont think a bigger t/b is worth it. im just gonna stick with stock, till i get a built bottom end then ill go ITB's