16v vs 20v

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20v

Postby GEOFF » Thu May 29, 2003 2:03 pm

Go the 20v, the 16 valves feel faster cuz there in lighter cars (300kg lighter ae92 ae86 etc) I have raced many a 16 valve and eaten them, I like 5 valves per cylinder cuz its kinda unique, adydas says its just a novelty, I say its not. Look at the ferrari 355, (5 valve per cylinder quad cam v8 ) when that engine came out it had the highest power to weight ratio for any production n/a engine, even better than the mclaren f1.
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Postby RedMist » Thu May 29, 2003 3:42 pm

In terms of flow then the 20 valve certainly outflows the 16 valve (at low lift) however the 20 valve tapers off radically towards the upper lift flow. The 16 valve really does radically outflow the 20 valve at anything over 400 thou. I suspect this is because most of the flow runs on the top of the port and is directed through the center port. The port dividers of the Blacktop actually make this radically worse.
In addition flow is not the only thing that differentiates the engines and makes power.

On the plus side for the 16 valve is swirl, tumble and much bigger squish bands. It also has many many years of development work behind it.

The 20 valve has a better induction path (straight to port) and obviously better low lift flow.

Very comparable, money no limit power. I really don't think you will get much better power from the 20 valve with double or tripple the budget.
Remember that the 16 valve Atlantic engine was restricted to 48mm carbs, and the airflow had to be twisted in the manifold to enter the head. Other regulations also limited the power output of Atlantic engines.
255bhp from a NA 16 valve should be achievable.

Standard there is no comparison, 20 valve all the way. However I dumped my 20 valve blacktop for a race 16 valve and the power increase was like night and day. Over 50bhp more and a better torque curve.

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Postby liftback » Thu May 29, 2003 3:59 pm

AE85coupe wrote:
MR2boy wrote:talking about the formula atlantic engine there is a formula atlantic head etc in this weeks buy sell for $3000


is it $3000 for the whole engine? or just for the head? where do you get hold of these formula atlantic engines?


As far as I know you cannot get them unless it is going into a race car. But you wouldnt want it for street use anyway as it would be a sack of shit as a runabout.
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Postby momentum » Wed Apr 28, 2004 3:36 pm

my mates bluetop 16v in a NZ New gt hatch could only poull a 16.4 1/4 and my standed black top 20v levin pulled a 15.2 1/4 and my car was 300kgs hervyer ask yourself 20v or 16v and they dude in the 16v knew how to drive it really well and was getting got starts but that is all he could get out of it
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Postby B1NZ » Wed Apr 28, 2004 6:32 pm

satchell wrote:oh yip fair enough, ill take that as a challenge. :twisted: hehe
im planning on buying an rgv250 soon (suzuki equivalent of nsr) so well have to have a drag one day. hehe (coz i know my mates cars wont keep up) hehe.


I once went for a ride on one of those, i think for memory it was an RGv250 walter wolf or something, scared the shit outta me, then theres the time i rode the gsx750R - Bikes are damn scary, i think i'll stick to 4 wheels and a cabin for saftey 8O
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Postby 10k 20v » Wed Apr 28, 2004 7:22 pm

in stock terms, 20 v wins.
all you need to do to a 16v red top his get your self a decent set of extractors made and change the cam timing. Does anyone know Ted Javis he has raced a corolla fxgt ae92 with red top for many many years now they even qualified for bathurst one year and they raced at bathurst with a pretty standard engine. He said he makes 145hp at the fly wheel in a light rolla so it honks pretty good. But yea next step would be cams but the class he is in they arent allowed to change cams.


Stock 20v already make that.
I made near on 165hp flywheel with just cams on my 20v
Going back on sat to see where i am now. Hoping close to 180 now

Also vvega and i are playing with a 20v with a to4e on the side and it starts to make boost at 2500rpm. Still tuning at this stage so not to sure at the outcome.
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Postby Leon » Wed Apr 28, 2004 8:50 pm

300kg lighter?

I don't think so Tim.

I had my AE92 GT (sedan) on the scales and it was 1080kg. So unless you are thinking a 101 or 111 weighs 1380kg .... well, you work it out.
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Postby 10k 20v » Thu Apr 29, 2004 7:54 pm

Hey, leon. Is that 1080kg with the cage?
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16v vs 20v

Postby jondee86 » Thu Apr 29, 2004 9:12 pm

Hmmmmmmm...... in Japan Toyota was getting wasted by Honda in the claimed power for 1600 N/A stakes..... so they had to put something in the shops with bigger numbers. Going 20 valve and VVT was chosen over trying to hotrod the 16 valve, and risk losing the drivability that is essential for the shopping trolley buyer.

My stock TVIS 16 valve is flat in the higher rpm's, while a stock 20 valve has a serious top end rush.... stock for stock there is no comparison !!! Modified will be a different story..... I'd sure like individual throttle bodies :)

Incidentally, 5 valves per cylinder may help the volumetric efficiency on a N/A engine, but 4 valves is more than enough for any forced induction engine.....

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Postby rcook_nz » Sun May 02, 2004 5:15 pm

AE85coupe wrote:
MR2boy wrote:talking about the formula atlantic engine there is a formula atlantic head etc in this weeks buy sell for $3000


is it $3000 for the whole engine? or just for the head? where do you get hold of these formula atlantic engines?


is that the atlantic spec motor ur talking bout if it is its only really worth having oneif ur sticking a big ass turbo on it cause its got all the forged internals other wise a black top or silver top will do the trick oh yeag and i personally like the 20v over 16 just cause its got more valves which i like
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Postby liftback » Sun May 02, 2004 5:53 pm

yeah i'd really like to see you chuck a turbo on an engine that has been completely tuned for NA racing :roll:
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Postby Vader » Mon May 03, 2004 5:26 pm

momentum wrote:my mates bluetop 16v in a NZ New gt hatch could only poull a 16.4 1/4 and my standed black top 20v levin pulled a 15.2 1/4 and my car was 300kgs hervyer ask yourself 20v or 16v and they dude in the 16v knew how to drive it really well and was getting got starts but that is all he could get out of it


Considering a NZ AE82 GT Corolla weighs ~950Kg I think your +300kgs difference in weight is a little dubious.

I ve raced several (close to factory silver top)Levins and FX-GTs down the the 1/4. None of them went under 16 secs.

That's one quick Levin you have there though : )
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Postby B1NZ » Mon May 03, 2004 5:57 pm

Vader wrote:I ve raced several (close to factory silver top)Levins and FX-GTs down the the 1/4. None of them went under 16 secs.



My Ae111 20v: 1040kgs (1/2tank of gas) 14.960 1.4 mile with exhaust

Loudtoys Ae101 20v: 1060kgs(1.2 a tank of gas) 14.9 with exhaust/intake Has run a lone 14.7 on the strip so weather you accept that or not i dunno?

But anyway just proving a point that they arent slow if you know how to drive them :wink:
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Postby Vader » Mon May 03, 2004 6:58 pm

^^sweeet. Stripped out though yeah?

Any quick AE101 FX-GTs around?
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Postby Leon » Mon May 03, 2004 7:22 pm

10k 20v wrote:Hey, leon. Is that 1080kg with the cage?


Nope, that was when it stock standard road trim.
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Postby Adamal » Mon May 03, 2004 9:43 pm

AE85coupe wrote:
MR2boy wrote:talking about the formula atlantic engine there is a formula atlantic head etc in this weeks buy sell for $3000


is it $3000 for the whole engine? or just for the head? where do you get hold of these formula atlantic engines?


I have the entire parts cataloug (I'm pretty sure its the whole thing, not 100% though).
As its a TRD engine, you should be able to order the parts in through an authorised Toyota Parts Dealer :)
Just be prepared to be broke for a while :)

Would definatly be the head for $3000. This is from an engine that produces 240hp remember! ;)
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Postby event2 » Mon May 03, 2004 10:23 pm

i perfer my bluetop corolla i drove a blacktop levin and it jst did nt feel like it wanted to go as much. my car has nothing down the bottom end but when the tvis opens up its pulls like nobodys bisness. its jst got filter and 2 inch exhaust. my mate has a ae82 as well but it pulls bottom end but has nothing the top end like mine you cant even hear the tvis kick in. but he has a much biger exhaust than mine and i think it slows it down a bit ahy. but mine has extractors but i herd they did nothing. so yea back to the topic i like 16valve
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Postby strap-on » Tue May 04, 2004 8:38 am

i read somewhere that ALL the 4ages are really equally as good and equally as usefull, it just depends what you want out of one and what application u are using it for.

what i wanna KNOW (and no "well IMO", or "i think...") is there any advantage to chucking the 20v head on the 4agte that ppl build all the time, or woul u be better off just ripping of the supercharger and hanging a hairdrier of a gze?
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Postby 89fxgt » Tue May 04, 2004 10:26 am

just out of interest, on the 20v, is the extra valve per cylinder for letting air in, or exhaust out?
um im stil learnin all this stuff so sori if its a dumb question or if theres sumfin wrong with how i explained it.
why do i have a consceince all it does is $&#$% with me
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Postby EVLGTZ » Tue May 04, 2004 11:09 am

:)
Last edited by EVLGTZ on Tue May 04, 2004 4:35 pm, edited 1 time in total.
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