BLAAST

What makes the turbine spool-up is exhaust flow.
and Exhaust flow is HP.
Yes, with any engine mod that increases CR, spool up will be improved.
With that in mind, the b16 head WILL improve spool up because I have seen it add as much as 50 HP to a b18B. not just up top because of the vtec, but down low because of the CR increase.

That's why i recommend the 0.48 a/r turbine only for stock B18B's with 140hp.

On the vtec ones such as the stock B16, b18C 1&5 and custom B20 vtec, I will offer you no less than a 0.63 a/r t3/t4. All these engines will make more power at 8 psi than a 0.48 a/r can efficiently support.

DeleriouS

how can you rev your car higher with a better head? i thought that all had to do with stroke?

sohcpwr

stroke does have a limiting effect on how high an engine can rev, but most of it is combating valve float/valvetrain weight

its nice to see someone who knows something about honduh engines back me up

Jcushing

how high you can rev has to do with ALL your components. you cant just slap on a new head and automatically rev higher.

also to the moron thats quoting compression information the the b18c head has the smallest CC volume therefor the highest compression keeping the block equal NOT the b16.

also volumetric efficiency has to do with how much air your engine can pump through it in relation to its displacement. what the dude is sayin is that at lower rpms the engine with the b18b head would flow more air though because its matched for lower rpms. i WOULD agree with this statement untill maybe under 4500-5000 rpm. untill vtec comes on the b18b head will be making more power thus more flow coming out of the engine thus sooner spool time.

Inquisition

Hmm, looks like someone understand VE. Actually the LS engine has a higher VE than vtec heads till about 6000rpm. Look at any Turbo'd LS dyno sheet. Torque will hold pretty well till about 5500-6000rpm and in the same breath make more torque than your ls/vtec with the same setup(even with the minute increase in compression).

Its clear a lot of you have your theory mixed up. The reason one would use a .48 ar housing on a LS because LS's VE is highest in the midrange of the powerband. .48ar housing will allow the powerband to shift into that part of the powerband. Using a .63 ar housing simply shifts the powerband more to the top end. Doing this is flawed in theory as you should try to have your parts compliment your natural VE curve but if you are drag racing you will want a .63 ar housing as your peak numbers will be slightly better. Your overall powerband will most likely be worse, but your "drag racing" powerband will most likely be better.

But again, what do I know.

PS: stop talking about hp so much. Torque is the brains behind the operation. Horsepower is just torque in respect to rpm. More hp at the same rpm = more torque. More hp does not always mean more torque

BLAAST

excactly.
If that b16 head helps spool up, it's because of the compression rate increase it makes.
the power gains due to the vtec at 4500+ rpm have nothing to do with your spool up because hopefully, your spool up will be over by then.

Inquisition

b16 head wont cause a turbo to spool faster than the same setup with a b18b1's head. Why is this so hard to understand? In the midrange of the powerband, the b18b1 will have a higher VE which will allow the turbo to spool faster. I don't understand why this concept is so difficult to grasp. Look at the torque curves. If a ls/vtec with a b16 head produced more torque at the low end, that would result in faster spool times. It does not, so it will not. End of story.

rudebwoy

even if a b16 dont allow you to have quicker spool, it will allow to take advantage of bigger turbos like allowing you to rev as high as the turbo's efficiency, I never used anything other than vtec so thats all I know, I never had experience with non vtec except when I disable it during tuning, and personally spool time stays the same, so you have a point, but it does allow you to rev higher and gain power from higher revs. regular is 8600 and sometimes I rev to 9100 I would not do that with a non vtec. so with bigger turbos vtec is better, just my opinion.

BLAAST

you can have 50 b18 vtec with the same compression rate and all different torque numbers. It depends on tuning and so many other engine parameters.

regardless of the dyno results,
More compression = more flow: Every single piston stroke will pack more air with a higher compression rate and that does accelerate spool up on a given turbine.

nonvtec

Man, listen to some of you guys talk up the LS head like it's the king




Here is a B16 powerband:


The end all of this thread is, spool will be about the same with a B16 head but you'll have 1500 more RPMs of powerband, nuff said.