4AGE 20V Performance - What have you got?

[Flannelman]

Anyone who has a 4age has searched the internet for Performance Gains. Yes, I have tried them. What I have found is as follows...

BLACKTOP THROTTLE UPGRADE
This is a joke. A back to back comparison of throttle response (NOT TOTAL kW OUTPUT) revealed a severe downfall. I build an engine for a friend with this upgrade and found that under 4000 was hopeless. Compared to my modified silvertop system, it murdered the blacktop setup.

Under dyno testing, the silvertop system gave greater torque at lower engine speeds while also giving the same peak kW reading in the top end. The dead throttle feeling under 4K made this car feel just as dead. AS point of reference, this engine was a blueprinted stock engine, blacktop intake cam and blacktop exhaust system. This setup gave a gain of 7kW over the stock Silvertop setup (77kW V 84kW)

I brought this exact engine an now sits in my car. Only difference is my lighter JUN flywheel and the smaller silvertop system. It has run as fast as 15.28sec at meremere (see link below) The "dead" throttle is now a consistent terror. Its under 4K acceleration is matched by being able to travel at 30km/h in top gear and being able to accelerate away from this speed. Something that was impossible before.

EXHAUST UPGRADE
This is a proven result. My own engine went from 78kW to 89kW with a header upgrade and timing fiddle. The exhaust system was already large at 2 1/4inch.
From this, its the Header system itself that gives the gain, NOT a larger exhaust system on the factory header system.

CAMSHAFT UPGRADE
Biggest difference with going from a slivertop to blacktop intake cam is FUEL ECONOMY. On a silvertop cam, I would see 600km to a tank. When I say "Tank", I mean using 48 litres of the 50L tank. After this switch I did a long trip and netted 700km. With smooth driving and limiting above 4k rpm I was able to do a personal best of 798km.

This is where things get interesting.

Internet says, 270 duration cams are as big as one can go on the stock computer. (Validation please by anyone here on Toyspeed)
BUT, there is also a problem with these cams as apparently the motor runs into a wall at around 7K rpm. This is about an increase of 1000rpm as the stock cams start to fall over at 6K. To me, there is something else missing in this chain and its the cause of many problems.

PLENUM
I did some research on this and found very little information on after market setups.
I have seen one once. A carbon fiber system 11 years ago. While my memory says its was a TOMS system, I cannot be 100% sure. Either do I have any dyno figures or anything concrete.
BUT!
While searching away I did read someone opinion (and it sounded true enough) that Yamaha designed the plenum to shut the intake up. The total opposite to making performance. Even in my own testing (see here - Tricking a 4AGE ECU viewtopic.php?f=3&t=92769) revealed very little.
I put my 1/4 mile gain in speed down to cold air than reducing a restriction. So to test that theory I build this



It is simply the biggest plenum that can be fitted without hitting the firewall, alternator, drive shaft, clutch master cylinder and heater tap.
No dyno evidence as of yet, but some speed runs have shown this setup to be just as fast as the tests with an "open plenum". Throttle response has lifted and the 7k top end is now no longer hitting the wall.

ANYTHING ELSE?
Sure. Compression increase, rotating assembly change for more RPM... OR go turbo.

I don't like turbo power delivery. Also, a turbo setup will require vehicle upgrades (brakes/suspension/tyres) and that's not including the drivetrain...
Also, all the things I have stated are 'bolt on'. (If you know what your doing, cam replacement is quick.)

The discussion I would like to start is, who has any of the above. What is it like to live with (be track car or road) AND has anyone else gone a step further than me and have 270 degree cams/large plenum/silvertop throttle bodies/ported head/after market headers. Something that I see as the killer combo to match a Honda "B16".

[1I1]

Tried running a blacktop with 270 degree cams on a stock ECU... smelt rich as hell at idle, no idea of AFR's but was simply a case of trying to move the car while waiting for my Link to show up. Personally wouldn't bother trying for the sake of trying to save some money.

My setup (stock pistons, untouched head bar 270° cams/springs, TRD headgasket, exhaust/intake etc and with VVT) makes for a sweet street car imo. Nice and peepy, doesn't demand you rev the tits off it yet is happy to if you so wish. Kinda tempted to see how Kelfords 280/274 combo reacts sometime.... And if driven nicely stil aint bad on gas. Did 7.9L/100km Auckland to Taupo earlier in the year.


Re: Open trumpets. We did back to back testing and found that while on this motor open trumpets did net the best power - running plenum + ARC intake chamber + short ram intake pipe with K&N pod filter was pretty much in line but with the added safety of a filter element.

[Flannelman]

Is that your car lith provided the dyno info on in the linked pages?

[1I1]

Sure is

[solitaire]

I don't have a 20v but this made for a good read, cheers.

[touge_ae101]

Not sure if I've put anything up on TS on this car for a while..

You've got the right idea for the air box. I also couldn't find anything on the Internet for a good reason.. everyone who used to play round with that stuff on bikes with carbs etc is now really old!! Old guy at work gave me the run down. Ideal volume for air box is about 30l, rounded edges help reduce resonant areas inside the box. For trumpets we run 110mm but design is the most important thing and also best length varies depending on cams. Trumpet size is largely determined by plenum depth. You need at least 20mm around the end of the trumpet with undisturbed air to not effect power. I think this is where the stock intake plenum is largely restrictive as you've alluded to above
As for cams the bigger the better 300 deg + is surprisingly street able. I could easily live with it on the street.

Remember compression is key. The more you have and the bigger the cam the more vacuum you can create to suck more air into the engine. under vacuum the smallest pressure drop will make a huge difference in your max flow rate. Hence we've decided not to port or polish the head as every ported we've tried hasnt made any decent power and the potential to lose power rather than gain power is too large.. The conclusion we came to is that while in theory it's possible to make an increase in power, Im unsure if anyone understands the flow patterns of the 3 intake ports to successfully port it. And realistically it already has a MASSIVE flow for a 1600cc head

http://img713.imageshack.us/img713/4749/bdiz.jpg
http://img845.imageshack.us/img845/3430/y1z0.jpg

http://img834.imageshack.us/img834/3296/8tjf.jpg

Dizzy is limiting factor after high 120kw power levels. Also once you get up that high cam angle sensor will give tunability gains.

Extractors make a massive difference not necessarily bigger but tuned lengths helps a lot. 2.5" is a requirement For exhaust size.


Have managed 146kw atw on E85 (gained 3-4kw over 98 octane). Still standard bottom end and haven't touched head only bigger cams and springs. Is crazy fast. Keeps up with k20 powered Hondas on the straights... revving it out to 9000rpm in the end. Cant go much over that without dry sump. Also sump is a bit too small bigger sump makes it easier to manage heat levels in the engine.
Engine has lasted 3 years of racing but has pulled the valves. All we can determine is standard valves can't handle the revs/heat generated. Also there is significant heat marks on the buckets and have heat treated shims. Who knows what's next looking at building a bit more of an aggressive engine to push over 150kw atw...

I've followed that you've tried a few changes. My only comment would be that small changes won't gain you anything you need to get everything working together to make an decent increase in power. Also remember toyota engineered it very conservatively while the 4age has gopd potential, they didn't make it aggressive enough in its setup. Big cams are your friend.

Edit: not sure how to fix pics only half loading. May have to click on url..

[Lith]

Nice rant, couldn't hope for too much better an answer than that

[Leon]

PLENUM
I did some research on this and found very little information on after market setups.
I have seen one once. A carbon fiber system 11 years ago. While my memory says its was a TOMS system, I cannot be 100% sure

Yes, TOMS carbon fibre.

I run one on my silvertop

[Flannelman]

Must say thanks for the feedback. Good, positive and informative.

Cam and compression go hand in hand. While the CR can go up on a stock engine and get a power increase, it's mandatory that when duration is increase, so must the compression. It's needed to compensate for the later intake valve closing which bring dynamic compression down. The only way to do this is scratch build and build the engine like an orchestra! All components must complement each other!

With a 5 valve, I have learnt that the head is a quantity over quality. It can provide large volumes of air and fuel, but it's a poor quality combustible mixture. The design produces tumble which has been shown to be inferior to swirl and the spark plug is in the worst possible place for efficient burn. To create swirl, things have to get imaginative. The same with moving the spark plug. I do have ideas... But are untested. Things like valve seat angle changes, angle milling the head and split duration camshafts. Or, go all out and google search polyquad. This is patented so you can't go and make heaps of heads like this and sell them without paying royalties.

Besides the 20V head, is the crooked alignment of the injection manifold. The only way to cure that is to make a custom one. Same goes for the extractors... Lengths are determined by cam timing, but it's not that simple. There are multiple designs, not just the 4-1 or 4-2-1. There is also duel pipes for each cylinder, merge type, cone type, and the lengths are no way exact. Altering the lengths alters what RPM band they work in. As its a small 4 cylinder why not tune a 4-2-1 setup with a secondary length that favours 2000-5000? And the primary length for 5000-8000?

Sorting the bottom end is not that hard. MRP is a good place to go
But that at the moment is fairytale land for me.

I will see my dyno operator and see when he can fit me in. Just to put some numbers to the plenum change.
Be nice to make it to the 100 club... (That may be a fairytale too!)

[touge_ae101]

lith you may be best qualified to answer this question... In a modern ish efi engine, does tumble vs swirl actually make a difference or is the tunability of cam timing and ignition timing good enough to compensate for any side effects? How many modern engines actually worry about tumble vs swirl etc?

The reason I'm wondering is once you go high compression pistons you've got such small gap between the head and piston and a weird shape on top of the piston to fill the gap that smoothness doesn't really matter as the main driving factor behind making air go in/out is the compression rather than how it flows into the chamber..

I agree with your comments on intake manifold design. the further out the injectors are the better for power. Look at bda/formula Atlantic spec intake manifolds..


We use a cone on our exhaust which makes a massive difference. The power band is flat from one end to the other and just keeps wanting to rev.. I quizzed the guys who designed it a few years ago - we got some acoustic engineers in chch to design the lengths for it. Their comments were the lengths of primary and secondaries weren't as important as the cone length. The pressure wave from the rear of the cone traveled backwards through all 4 runners at a rate of 1540ft/sec and you wanted to this to reach the back of the valve during the valve overlap to suck more air through the intake.
an old guy I talked to reckon on a single cylinder speedway bike with a properly designed intake and cone exhaust they could see up to 15-20% increase in power.

[Flannelman]

The design produces tumble which has been shown to be inferior to swirl

I will expand in this. When describing air movement I'm referring to the greater mass of air.

Tumble is when the air enters the cylinder and rotates in an up/down motion from the cylinder head to the piston and back to the cylinder head.

Swirl is when the air enters the cylinder and rotates around the cylinder walls.

Under comparison, once the intake valve is shut and the charge is being compressed, the Tumble motion begins to slow down as its energy is being countered by an uprising piston. On the other hand, Swirl accelerates as its energy is not hampered by the piston motion. (There will be a physics gas law to explain this in greater detail)

By the time the spark plug fires, the Tumble motion has all but stopped leaving a stagnant charge to try and burn as fast as possible. It is most likely why heads that produce Tumble demand high compression/large squish areas to get the flame speed up. As for Swirl, its chamber looks similar to a tornado. At the time the spark plug fires, the squish area is moving the turning mass and "squishing" it towards the spark plug. The flame speed inside this cylinder exceeds the Tumble port with less compression. Adding it up, a Swirl design can exceed the Tumble design with less ignition timing and lower octane fuel.

If BOTH heads flow the same CFM then the Swirl design wins. If the Tumble design OUTFLOWS the Swirl design by a greater percentage than the gains from Swirl, then the NET result will be that Tumble produces more power/torque because of air volume. The ultimate way is having superior airflow with superior combustion design.

The word on spark plug placement. In the stagnant chamber of the Tumble port, plug placement needs to be in the center to eliminate the possibility on any odd airflow behavior that is created around raised piston tops and valve reliefs. In the Swirl design, the spark plug wants to be in the hottest spot. Starting ignition here eliminates trying to burn it last (this promotes very ugly combustion eg detonation). So, usually the best place is somewhere close to the exhaust valve and exposed to the swirling mass.

Sadly, the King of Swirl is dominated by two valve engines as air entry is from one side of the cylinder.

As for the debate over what is the better breed, few engines that are pushrod remain in production. I think all are V8 (or the Viper V10). When it come down to the crunch, its these factors as to why Ford and Holden can still beat the Twin Cam V8s in V8 Supercars.

When you want the winning edge, you have to run the best. That includes being open minded to the best ideas.

[Flannelman]

Sorry, forgot to add, which is why I like your exhaust! Awesome!

[Lith]

lith you may be best qualified to answer this question... In a modern ish efi engine, does tumble vs swirl actually make a difference or is the tunability of cam timing and ignition timing good enough to compensate for any side effects? How many modern engines actually worry about tumble vs swirl etc?

The reason I'm wondering is once you go high compression pistons you've got such small gap between the head and piston and a weird shape on top of the piston to fill the gap that smoothness doesn't really matter as the main driving factor behind making air go in/out is the compression rather than how it flows into the chamber..

Haha not so sure I am, but I'll try and weigh in for the sake of conversation

I don't know that swirl or tumble are specifically targeted - at least as a lone thing when the engines are designed... really they are just a couple of phenomenon (among others) which can be chosen to help balance between cylinder filling, even mixing and allowing good burn speed, knock resistance etc and play their part as much as they ever did to get the desired result. Being able to fine tune cam and ignition timing are great, but no matter how well optimised they are the result can only be as good as how quickly and evenly mixture can be burnt from it's starting point without losing it's shit along the way.

The biggest advantages to swirl are probably seen at lower engine speeds and low cylinder filling (/load) levels - so allowing nice running at light load and with lean mixes, not saying that it's ONLY there but that's probably where it REALLY makes a difference and I'd say a lot of why OEM put a lot of effort into it. I think of the swirl/tumble as ways to incite more turbulent flow in order to increase BSFC (and having decreasing gains the harder you are pushing) but a lot of the things that improve them tend to reduce VE, so when modifying cars for outright performance I guess if you're looking are developing the motor and how confident you are in terms of developing different parts of it.... I'd consider how much your power production you think you can influence by improving BSFC as opposed to increasing and maintaining VE, and on that note I think it seems to be a good time to refer to Flannelman's comment on V8 Supercars and then compare how those do their thing to how F1 teams have developed their engines to do their thing Extreme example and I know it's not really an entirely fair example, but still has to put some perspective on things.

Fortunately not all the magic is during the induction process, as your comment on compression (the gases keep spinning and mingling when the piston goes back up, and back down again) eludes to

[petrolhead]

Interesting reading chaps.. I'm currently reading a book on head work, (David Vizard's, How to port and flow test cylinder heads).
Worth a read if you are that way inclined..

[touge_ae101]

I think what we all have to keep in mind is all this talk is only in theoretical Wonderland. In reality by doing the basics right and making everything work together some really good results can be reached without much effort.

Both marks corolla at 120kw atw and our ae82 at 146kw atw were both done on standard bottom ends and heads.. Theres a lot to be said for leaving the head and bottom end alone and focus on the basics. I don't think these phenomenon we are talking about would actually make a difference until you are chasing over 160kw atw.. (I think this is the power limit of the blacktop head with unlimited cam/compression)

[Lith]

I think what we all have to keep in mind is all this talk is only in theoretical Wonderland. In reality by doing the basics right and making everything work together some really good results can be reached without much effort.

Both marks corolla at 120kw atw and our ae82 at 146kw atw were both done on standard bottom ends and heads.. Theres a lot to be said for leaving the head and bottom end alone and focus on the basics. I don't think these phenomenon we are talking about would actually make a difference until you are chasing over 160kw atw.. (I think this is the power limit of the blacktop head with unlimited cam/compression)

Totally agreed - well I don't know what the limits are, but I think a lot of the time people STILL get too deep into tweaking stuff when getting the basics right with engine right would be worth so much. By that I mean overall tuning, and while I consider ECU tuning as part of that I am more talking complimentary collection of parts to suit the target can really count for a lot. I'm more from an NA Honda background and not sure what the manners of your thing is like but have to say I was really impressed with how effortlessly and competently Mark's car made it's power, before his I'd not been overly impressed with 20vs I'd been around but had for a long time been curious about how they'd be with a nice collection of parts.

The power aims for his were 110-120kw and he didn't want to compromise much drive-ability so the cam choice was possibly a bit conservative, but his car is probably the best street-spec 1.6litre NA I've been in so far... better anywhere than stock, when there had been the expectation that for the peak power gain there could be a little compromise at low rpm. Makes me wonder what the next size up (284/278s) would have been like!

[XS1V]

I and other people have had issues with the blacktop hydraulic tensioner so switching to silvertop timing gear (also have to change oil & water pumps) has been a good switch. Just have to be careful as timing marks on oil pump and cam sprocket are in a different position so make sure you use the correct pair or mark accordingly You also need to change two lower cam covers to silvertop versions due to changing the pumps.

Brad

[matt dunn]

The silvertop and Blacktop cambelt drive sprockets have different marks as you have stated,
but they are also different widths, so the front pulley is also a different width too.
A ST camdrive sprocket and a BT front pulley puts the alternator belts slightly out of place.
I have struck that too.

IMO it is easier to modify the hydraulic tensioner guts with a bolt through it to make it a purely mechanical adjuster.
It's a bit of work to do but saves changing a lot of other bits.

[Bazda]

Or we have these:
http://www.mrpltd.co.nz/product/341/mec ... cktop.html

$85 for TS members.

Nice discussion on the 20v power capability. With a 1600cc bottom end id say 240hp is the max you will get.
Up those ccs its then proven to make up to 270hp. The heads we get CNC ported flow enough to support this power.

Im in the middle of building one, its def not cheap to get these numbers! id say the engine will cost me $20k+ to acheive this with reliability.

[touge_ae101]

Will be interesting to see what the new engine in the ae82 makes with the pistons and valves you've supplied. The guys at colliers are very impressed with the quality of the gear so that's normally a pretty good sign..