20 valve vs 16 valve head on 4agte

[dickhead]

Hey, is there any advantage of one over the other?

[trueno_20v]

go for the 20v head

[shazeal]

Ive been doing alot of reading up on this as Im planning to do it in the future. As far as I can tell, 20v has better intake setup over 16v, 16v has better flow through the head as the extra valve on the 20s causes dead spots. Best setup if you are going after market computer is 16v head with 20v ITBs.
Again with the heads 16v heads, small port is better at low down torque, big port is less restrictive at high rpm. Ive also read some guys use TVIS with the big port heads to spool faster and have the extra flow at high rpm, but that means no ITBs

All very confusing, im probably going the 16v bigport head + 20v ITBs route with a megasquirt.

[TRD_ZERO]

OK this is what i have heard................dnt quote me on it.............. The quad throttle bodies arent too good for being turbo'd as said by speedtech i think. And the 16 valve heads create a better velocity or something along those lines. but hey its only what i think i have heard. Im going with the 20v turbo setup for a little fun.

[dickhead]

Ahh. Might stick with the 16 valve bigport then. What are ItB's?

[dickhead]

individual throttle bodies?

[shazeal]

Yea thats right. Not sure why ITBs would be worse for turbo? Im along way off doing mine so plenty of time for research

[dickhead]

Yeah. I see you can buy adapters to match 20v ITB's to 16v heads. Looked on google and they are $250. I think it was NZD

[Bazda]

From my experiences i'd go with a 20v blacktop head, peopel always think of the silvertop head adn compare that to the 16v head, and its not really that much better but i've been told in standard form it does flow better than the 16v head.

and ITB's all the way, better response, maybe harder to tune if u have a cheap ecu though.

I really think the blacktop head is what got me my power, i definatly wouldnt of got it with a 16v head.

[dickhead]

What do they go for, the blacktop head with the ITB's?
I will be running a link

[Caveman]

I think it would be more cost effective to cam your 16valve head with bigger lift and longer duration. Its doing the same thing as a 20v head - flowing more air.

If you run shim over bucket you may have to change to shim under bucket (or shimless) and you may also have to upgrade your valve springs. Talk to a cam regrind specilist to find out your options.

You will definitly have to upgrade your ecu because for the same pressure you'll be flowing more air and the stock ecu wont compensate for this very well.

[Bazda]

What do they go for, the blacktop head with the ITB's?
I will be running a link

I think link can do itb's but i dont think it can tune them very well at low rpms and ligght throttle........

[TRD_ZERO]

So then what is the best suited ecu for quads? Im thinking of something around the same price range as the link, as autronic is a fair bit different. Isnt the new link G3 capable of handling the quads quite well?

[dickhead]

It says that in the specs ay

[slighty_sykotic]

So then what is the best suited ecu for quads? Im thinking of something around the same price range as the link, as autronic is a fair bit different. Isnt the new link G3 capable of handling the quads quite well?

Yeah, its alot better according to a couple of people I have talked to.

I will find out soon though

[flygt4]

What do they go for, the blacktop head with the ITB's?
I will be running a link

I think link can do itb's but i dont think it can tune them very well at low rpms and ligght throttle........

yep thats it. i run a link with ITB's. andre has had a few goes at getting mine running right with the quads, and on light throttle and on the overrun its always going to be a bit poppy/burbly and you get the odd flat spot when you let the revs rise from low rpm.
its actually gotten to the stage im really happy with it now tho , its just something you put up with. its had 3 tunes for various fuel systems etc , and its gotten better each time.

the silvertop head is actually not too bad if you clear the restrictive exhaust side. mine has been played with on the exhaust side and it seems to flow very well in the top end.
i think one of the the main improvements between b/t and s/t is the exhaust ports anyway.

i remember when i first got it tuned , i was told that quad throttles are mainly for wank value on a street car anyway, as they are best when you're using full throttle a lot , a la drag racing.

[vvega]

What do they go for, the blacktop head with the ITB's?
I will be running a link

I think link can do itb's but i dont think it can tune them very well at low rpms and ligght throttle........

yep thats it. i run a link with ITB's. andre has had a few goes at getting mine running right with the quads, and on light throttle and on the overrun its always going to be a bit poppy/burbly and you get the odd flat spot when you let the revs rise from low rpm.
its actually gotten to the stage im really happy with it now tho , its just something you put up with. its had 3 tunes for various fuel systems etc , and its gotten better each time.

the silvertop head is actually not too bad if you clear the restrictive exhaust side. mine has been played with on the exhaust side and it seems to flow very well in the top end.
i think one of the the main improvements between b/t and s/t is the exhaust ports anyway.

i remember when i first got it tuned , i was told that quad throttles are mainly for wank value on a street car anyway, as they are best when you're using full throttle a lot , a la drag racing.

more expensive ecu's have more resolutions so you can tune around all that

thast what bazzda was tring to get at

[flygt4]

yep you get what you pay for