Discussion: blacktop 20v: the road beyond 200HP

[86er]

Ok Ive started this topic on 3 other forums u can follow them here
http://www.toymods.net/forums/showthread...post346646
http://www.hachiroku.net/forums/showthread.php?t=3356
http://www.ae86drivingclub.com.au/forum/...id=303313&
some nice info posted especially on the toymods forum

Now everysince I got on the 20v blacktop craze and started the swap I've been troubled, when guys first started megasquirtin these I was impressed by the resulting figures and it made sense to venture this road as a stock BT with open stacks, exhaust, and MS weregetting from 140-150ish at the wheels which i thought was great something a 16v honestly needs alot of work to acheive (not saying it cant reach that level) cuz i know better havin had 2 bigports before which were relatively stock. fter "jumpin on this band wagon" i started doin all kinds of research into modding the 20v further I discovered that after market support for the 20v pretty much suscks and honestly there is a huge Gray cloud surrounding the 20v and modding it WORLDWIDE!!!! Thats what all my research has led me too I dont think people truly realise the potential of the engines, But i must admit I myself am not sure of that FULL potential either, but nly few have tried and succeeded. Some would quckly jum to say that the Japanese have preoven the limit of the 20v but my findings lead me to suspect otherwise.

Anyway the purpose of this topic is to discuss and truley try to discover the potential of the blacktop mainly, the silvertop will also be covered as it applies at this level of tuning, but until u pic down the head and start fixing it it honestly doesnt compare to a blacktop. The latter silvertop is better though and closer to Blacktop.

So firstly my findings, below i will post linnks to various forums where either people have sucessfully developed th 20v or have thoroughly tested it in terms of mods and power gains to a point

WheelsJamaica.com these guys have truley proven with what are some very lengthy topics (one 25+ pages) what a 20v blacktop is made of and how well the stock motor responses to the right mods

http://www.wheelsjamaica.com/wheels_foru...ic=12990.0

http://www.wheelsjamaica.com/wheels_foru...c=32929.40

http://www.wheelsjamaica.com/wheels_foru...ic=45443.0

http://www.wheelsjamaica.com/wheels_foru...ic=44599.0

there is a wealth of info in above links and real info instead of guessin
Now that confirms that a stock blacktop with proper velocity stacks, headers, and exhaust will produce around 140WHP now the test car is fwd which is probably why with same mods and a megasquirt people get 145ish-150whp as we have more drivetrain loss.

SO at 20% drivetrainloss people seem to average on a ae86 145whp is like 174 at crank. That to me is very impressive and motor has even been open yet.

Now this guy in Aussie has a very impressive BT

20v_KE25 Wrote:this is my KE-25 race car which is used mainly for club sprints. I bought the car for $300 through work as a trade in. it started off as a granny spec. 1200 which was quickly converted into a 4AGE 16 valve RWD with T50 and AE-86 disc break rear end with TRD lsd. Front brakes are series 4 RX7 with Saab 280mm rotors. The rears are 300ZX turbo with MX-73 rear discs. About 4 and a half years ago I decided to make the move up to a Black top 20 valve with a TRD close ratio gear set. The engine is still currently running stock ECU and has proven to be both reliable and very competitive, it hasnt lost a race in my class in about 4 and a half years and it holds the lap record for my class at Philip Island with a 1:54.33. At the recent Chasers dyno day organised by Glen (Celica RA45) it pulled out 121.4KW's at the rear wheels!! Here are some photos, doesn’t look too special to the eye but it does the job.













"At the recent Chasers dyno day organised by Glen (Celica RA45) it pulled out 121.4KW's at the rear wheels!!"

that car is pumpin out over 190crank hp when you work it out. which is impressive with short mod list, my only explaination for his figures is one the race gas and 2 the electric water pump. But hell when i think about it JAPANESE n2 cars with fully built 20vs are usually said to be 200PS or so with same race gas, usually high duration cams high comp pistons, management, steel cranks etc etc. :confused:

Here in is where my problem with the japanese 20v developmant lies

example Tysuchia's(spellin) 86 has a trd bild blacktop with full exh management, wasted spark, and i think 272/288 cams high comp miata pistons(use to have toda) and tuning tunin and they CLAIM his touge car is 170PS thats bull i dont see anyway that car could be less tha 200hp based on all figures the assuies/americans and the rst of us are gettin. Thats less than what can expect on stock motor with a Megasquirt and bolt ons.

[86er]

continued

Here is a nice link from Garage annex site where the build th 20v N2 car's egine and dyno it at various stages and with various cams(personally i still find these figures a bit short)

translated
http://64.233.179.104/translate_c?hl=en&...uage_tools
japanese original
http://www7.airnet.ne.jp/annex/engin_seisakuki.htm
in the end the get about 213ps with tODA　288?9mm lift IN and 304?9mm lift EX cams and built engine

this is still invaluable info

now I perosnally think at this level of tune figures should exel well over 200hp in te 220-230crank hp range so i cant help but think something is wrong look at this

http://64.233.179.104/translate_c?hl=en&...en%26lr%3D

Satoru Works drift ae86 20v 1600 produced 244PS thats sould more like it not sure figures of the 1800variant or the specs but if anyone has them please share i suspect they arent much different from most built 20vs in japan but maybe difference is in compression and cam lift.

I say lift becuz all the 200+ 4ag16s i see seem to run very high lift
Here
http://www.jtuned.com/content/templates/...6&zoneid=1
the FA 16v by Hasselgren while cams are only 272 lift is 10+ and 11mm
Also I have a 86Super Tuning magazine here from japan where they cover the tec arts 16v which is 230ps also has very high lift cams in that same range, and 110mm velocity stacks on ae101 ITBS, doesnt say the compression ratio but all the tecarts cars have 230ps their drift car and n2 car and and all the cars with that spec engine have it. the show the build up of the motor in detail the magazine i will try to get some pics up.
Anywwway im suspectin that the lift has something to do with it, the only real choice in japan fr 20v cams is toda all there 20v cams are limited to 9mm lift, kelford makes some 20v cams and there highes race cam has like 10+mm lift http://www.camshaftshop.com/camshafts/vi...-camshaft/ and a nice powerband while still under 300degrees duration
also Cat Cams makes some aswell in europe somewhere lol
with 11mm lift 291 duration http://www.aeu86.org/viewtopic.php?t=405...72b4a6c496
waiting to see final results for this motor

hell there was even a guy on club4ag the otherday with some mild 264cams and basic bolt ons in blacktop he was gettin like 160whp which is in 190+crank region still way more that the japs these were toda cams. So I call BS on the japanese 20vs except that satoru works guy. CAN anyone please post his specs if u have them. Thanks

Now For all you club4ag people who are here now lol MR.John from club4ag who drifts blue rolla recently posted that hasselgren has built a silvertop(yeh i know what i said but like i said at this level they are even as heads wuld both be ported out etc) for Taka Aono 2007 drift car. I consider him a reliable source and Im waiting too see the mtor in this comin year and more specs. ANY WAY ITS SUPPOSE TO BE 306HP at crank. I am personnally confident about this but time will tell.

LAtsly the new valvetrain from Barry (dot Racing) no info on improvements yet but about time oversize vales were on market.

now all this is well and good but whats the secret and the truh behind a heavily modded 20v an whats the recipe to push a reliable one pass the 200mark? thanks what i want to discuss.


Now i know with Na especially parts have to work together and produce power togther otherwise u will not make full power potential so please feel free to share opinions on any thing u think i list that would not add to setup and goal of 220-240hp+ at crank

Im thinking a blacktop base
kelford race cames 298duration 10+mm lift
12:1 compression(would prefer 13:1 but how reliable i know this is is controversal issue few venture so high)
dot racing oversize valves and spings and retainers
ported head
valve angle job
100mm-110mm velocity stacks to to open powerband
to keep down cost stock crank (unless a steel one is found at good deal)
forged rods or stock(people still got issues with stock BT rods)
high rise 4-1 header with 45mm primaries and 2.5" to exhaust
crank fire ignition
what size injectors??
balanced bottem end
Any theories on the intake flow anle as in having itbs angled up to same angle as intake or closer( not sure how much this helps as the formual Atlantic motor has a straight intake)
the very same electric water pump by craig davies to elimitate the water pulley and get some lighter pullies for others
The six speed AZ6 miata box the oldskweltoy is investigating as i too like 170bhp's 6spd 20v setup.
what am i forgettin?

ok and....... GO!!

[86er]

another double post anyway theres great info to be found on the toymods reply

let me guys know ur thoughts

[86er]

double post

[BenR]

Right....interesting topic.

Put quite simply, the downfall of the 20v engine is the fact that it is 20v.

And as with all engines, the ultimate ability of that particular engine to perform is the cylinder head.

ALL varients of 20v that i have seen are apalling. Sure you can squeeze a whole shed load more valve area into a certain bore size, but valve area is only one part of the equation.

Ignoring the bottom end assembly as its quite easy on any engine to sort out any issue that it has, but the 4age doesnt have any really.

Product support for the 20v is limited because its not wanted, the limits of the 20v are too low compared to the 16v to bother with high levels of support.

Now the 20v solution is a mass production one, its easier to gain raw cylinder head flow using an extra valve. Simpler and cheaper castings, inexpensive design phases, high port volume etc etc. It was easier for toyota to bung in another valve than to piss about developing an efficient 16v head.

However this provides problems to those who want to tune to the extreem upper limits. The ports are just terrible. There is no control of flow down to or between valves, the port volume is massive........all in all, a horrible show for port efficiency, and thats the name of the game when were trying to maximise the efficiency of the valve area we have available.

The 20v has comparable area to a 16v head with 32.5mm inlet valves, which in itself is enough for about 240-250bhp without straining too hard.

Christ, i dont even know where to carry on with the poor points. Staggered included valve angles mean poor cylinder filling and high tumble values.

To efficiently modify the head to use the available valve area would take considerable modification. To this date i've yet to see anybody modify a 20v head to any decent level, which is why they all sort of cap themselves at 200-210bhp. To make use of the setup i would start with a BT simply because its all hogged out from stock and gives me the space to do what i need to do. Your going to have to strip the whole head of all material which isnt part of the parent casting......then break out the old tig welded and mini torch as your going to have to fill that port something crazy. You want to build up the floor of the port, and bring up the bifurcations between valves to at least halfway up the port. That in itself will be a terribly difficult job due to the limited space, in some cases you might be limited to working with a liquid ally or epoxy if you dont care about what it looks like.

With the base sorted you can modify the head to a much better shape........what this shape is another subject in itself.

Port filling is becoming a popular trend among racing engines where manufacturers use large valve area and large port volume to increase efficiency, and variable valve technology to help with the associated low engine speed torque issues that arise.

Then you have the chamber issues, its large with zero usable quench, even in the ST. Poor combustion and thermal efficiency........basically wastes alot of the burns energy in timing. Subceptable to det because of far off end gasses etc etc.

I wouldnt bother worrying abuot anything else until you sort the heads basic flaws.

As for a 1.6 20v generating 206bhp at the crank, i highly highly doubt it.

[robokill]

As far as I know of 20v's is that they are easy to get a bit higher. Around 20hp more. But then it gets hard. While when you do the needed work on a 16v you have "unlimited" posibilities.

TO be honest the 20v does sound nice! And most important its reliable to start with more power than a 16v.

[BenR]

If you think about it, if the 16v had comparable cam valve timing events, compression ratio, throttle bodies and quality cast cylinder heads from the factory, it would be around the same output.

[86er]

Thanks for reply I cannot argue with you on such a technical level becuz i am not so tecnical, but I will wait and see what sort of resluts i get from my current set up I am also gonna use a EWP gonna buy it soon, but based all info shown on the various links i have posted and various power results I am confident the engine is capable, Alos Bill Sherwood said in same topic on toymods

"One of the problems the 20v's have is that the 23mm cam buckets simply aren't big enough diameter to allow a big cam, and that limits the power.
The others are the flow interference between the three inlet valves, the poor combustion chamber shape, and the small squish areas.
The rest of the engine is very good though.

The heads flow better than a 16v in just about every test you can try, but a flowbench is just a part of the picture, and can be misleading.
The curtain area of the 20v inlet is bigger, but again the kind of airspeeds you see in a flowbench aren't really fast enough to show the real picture."

But will wait to see more info on the hasselgren motor as it does exist granted that sort odevelopment is beyond our budget, But The more i see the more confident I am that gettin that 200bhp mark isnt too too hard and doin so on a somewhat reliable motor is possible, I still think surpassin that mark is posible aswell

[BenR]

The engine is capable of 200bhp easily, its been done a million times before with relatively little work.

I'm just pointing out that the 16v is vastly superior.

[david]

also you have to consider this:
if you are building a 200+hp engine
if you are going to build a 16v you need the under bucket shims
but the 20v already have them..
and it is actually cheaper to buy a 20v blacktop head with throttle bodyes than buying the under bucket shims..
and the prices on cams, adjustable cam gears, piston and rods etc isn't vary very much if it is 16v or 20v..
and 16v you have to buy carbs or throttlebodyes which the 20v already have..

maybe the 16v is better if you want more than 220hp
but I think the 20v is cheaper to get 200-220hp...
what do you think?