4A-GE + Individual thotlle bodyes

[ZaX]

Please help us with some good info about 4A-GE + ITB.

Our member, Ivica aka Pero, would like to do this modification, but we can not gather enough of good information about this topic. Fair amount of money is in question, so we don't want to make any mistakes.

Ivica has standard rebuilt 4A-GE blue top in his Levin. It's MAP sensored, TVIS, big port engine, TRD head gasket, A'pexi intake and 5zigen exhaust manifod + straight thru exhaust pipe.

Planed upgrades are:
camshafts 288IN/288EX
adjustable cam pulley x 2
valve springs
Individual throtlle bodyes
Injectors
Some kind of after market ECU

With the above mods, this should be very good and powerful engine.
Targeted power is 170-180hp with good amount of torque in mid and high revs (we don't want 200hp with very narrow poweband, pero likes drifting so torque is more important).
This car would be driven 10-15 times to track per year, rest of the time it would be daily comuter.


Questions and doubts i have:
How does the cam lift afects the manner of engine? What's the differenc btw 288 7.9mm lift cam and 288 8.5mm lift cam?

Valve springs, do we need whole set (shims + buckets), or are the only springs enough? I know about the yaris bucket "hack", but what kind of buckets to order?
http://www.toda-racing.co.jp/product/one...4ag-3.html
http://www.club4ag.com/faq%20and%20tech_...uning.html

ITB's, what make?
What is exactly needed? Vacuum plenum, throttle position sensor adapter? What type of funnels to use (lenght)?

Injectors
Do we need bigger injectors? AFAIR stock are 185ccm.

Aftermarket ECU's
Power FC is not officialy supported by A'pexi, but i saw ae86 running with it.
Freedom - does not have English translation.
Motec - too expencive
Autronic - same as motec.

Please make any good suggestions/web links to help us built this very special AE86.

[mo-racing]

i am no ultra professional but i guess more open time on the cams is good. more lift is even bether. at least it´s the gap between valve and valve seat causing the main restriction in the channel so lift is very important.

[Ivan141]

Only summing up what I've read on club4ag and other places:
I would at least buy better valvesprings for 288 cams, you're going to make power at a lot higher RPM so you'll want to eliminate valve float.
Should you choose to go 8.5mm lift (which is only a good thing, these engines have very little lift as it is because of the relatively small diameter of the buckets, my volvo 360 has 11 or 12 mm of valve lift, but thats an 8v) then shim-under buckets are necessary to prevent the tappets getting loose. The club4ag tech reference ahs al the part.nrs you will need, you need to measure valve clearance and order them accordingly. BTW, they are not cheap, but a lot cheaper than the TODA ones.

[NoHachi]

Ok Zax,

The modification you are describing is not a small one. I would never attempt it if I didn't have acces to a steady state dynometer. Steady state means that the dyno can keep the engine at a constant rev number, while you modify throttle settings and tuning.
The standard dynojet dyno's that every shop seems to have are useless for tuning. They can only simulate transient behaviour. the trouble starts in steady state operation like cruising. The engine starts to heat soak and do strange things.

Second. These kind of cams and daily commuting do not go well together. If you ever get into a traffic jam you will know what I mean. Idle quality etc will be hard to get back to OEM quality.


With all this said...it would be one hell of a little screamer and blast around the track.
To answer some questions:

Quote:How does the cam lift afects the manner of engine? What's the differenc btw 288 7.9mm lift cam and 288 8.5mm lift cam

See above

Quote:Valve springs, do we need whole set (shims + buckets), or are the only springs enough? I know about the yaris bucket "hack", but what kind of buckets to order?

You have to set the valve lash of the engine (distance between bucket and cam). The only way to know the correct buckets to order is by measuring this lash with a feeler gauge. I think that there was a conversion method to determine which buckets were equivalent to which shims.

Quote:ITB's, what make?
What is exactly needed? Vacuum plenum, throttle position sensor adapter? What type of funnels to use (lenght)?

Best power can be expected by running a LARGE plenum over the ITB inlets, feed it via a cold air inlet. You will need the individual runner throttle bodies, some sort of throttle linkage, a new fuel rail and regulator, some sort of vacuum collector for the map signal (beercan wil do fine or if you go with the plenum, then you don't need anything) and most importantly, an ecu that is capable of running MAP/TPS Blended fuel en spark curves.
The biggest problem with the big cams and IRTB's is getting a map signal at idle. usually this is very week. Using some sort of MAP/TPS blend can sort some of the issues with this signal as well as some of the MAP issues on acceleration.

Quote:Injectors
Do we need bigger injectors? AFAIR stock are 185ccm.

If the stock injectors are 185cc/[email protected]/mm2 then there isn't that much potential left in them. I hear people using them up to 160bhp but you would be hitting 100% duty cycle and the sloppy fuel delivery that goes with that.
@80% duty cycle the injectors@stock pressure are good for 132hp. Upping the fuel pressure to 4.7kg/mm2 should be enough, but I'm unsure whether the stock fuel pump kan handle it.
I would suggest using the high comp 4A-GE 235cc/min injectors at 3.9kg/mm fuel pressure. That way you have plenty of room left should you ever decide to shoot for more hp.

So you'd need a fuel pressure regulator too, add it to your list.

@stock pressure and 80% duty cylce you would need 265cc/min injectors.

ECU: whatever your engine shop is used to tuning. THE most important factor in this kind of setup is the way it is tuned. If you have no previous experience in this then let an expert do it. They usually have one type of ECU that they are familiar with..use it.
I would also strongely suggest investing in a Wide band lambda sensor (WBO2) and a knock sensor that you can hook up to some earphones while tuning.

Good luck!

[mo-racing]

did you ever hear of a guy called ron hellenbrand? he is a dutch guy and only one of two i ever heard of tuning the original 4age ecu. he used to post time by time on the german toyota forum. there was also a rallye ae86 pictured in this forum from a guy called hellenbrand (maybe hes the guy)

he tuned a ae86 4age with high compression pistons, 270 or 280° cams (don´t know exactly) and ITB with stock ecu just running trottle position and rpm sensors (no MAP) to 180hp. stock exhaust manifold and good idle.

i am shure he wants to see some money for his work but thats an option. ... at least you can see what is needed to get on this power level. good tuning seems to be the key - thats clear!

[mo-racing]

did i forget to say he had bigger injectors and i guess a bigger fuelpump as well. but anything else was stock afaik.

[NoHachi]

Running just TPS for the street is not acceptible. The engine cannot respond to any change in VE (aka clogged air filter or carbon buildup in the exhaust) or changes in ambient conditions. TPS systems are for the track and more like carbs. (need constant tweeking).

Ron Hellenbrand is a very knowledgable person. The things he's done to that engine are not that simple, lots of little things that get done in between. Basically he knows how to totally reconfigure the stock ecu. What that really means is that the only "stock" thing of his ecu, is the outside of the box and the chips it is using. The programming is all custom.

[mo-racing]

yes yes. he seems to be realy deep into that matter. he is measuring different cams with obviously the same specs to find out which is opening quicker. also he knows whats important to look on at pistons. ... and he knows a bit about electronics as well, i guess

to run an engine without MAP realy seems to be strange but i think with the right tuning you can get it running pretty well. it is allways a compromise esspecially on a smaller budget.

i think we are getting a bit off topic. zax was just looking for advice for his setup ... wasn´t he looking for aftermarket ecus?

[NoHachi]

I didn't think that it was off topic. Just reminding everyone that that wasn't a stock ECU, just stock housing and chips

I wouldn't run TPS on a daily driver. I have tuned such a system and even had the chance to take a quick spin in it. Love the throttle response, but it has to much issues to be an easy daily driver setup.

Back to the ECU. As I said earlier, if you want a high power setup, with good street manners then there really is no way around a TPS/MAP blended system.
Look herehttp://www.sportcompactcarweb.com/projec...rojsubaru/ for some info on the TEC2 system, issues with tuning and uses of blend algorithms
The only systems I can find that use blend are motec and TEC, guess you get what you paid for.
Oh yeah, there is one system available that can use blend and costs around 1/10th of the other systems..Megasquirt2 with additional dual table and blend firmware updates. Be prepared to do some learning thouh.

[Ivan141]

Ron Hellenbrand is not the rally-car hellenbrand. It's his family (who happen to have a lot of ae86's for sale at steep prices).
Just thought I'd point that out. He told me he wasnt very fond of his uncle..
I wouldnt consider reprogramming of the stock ECU unless he would be willing to explain it to me, which I'm sure he wouldnt like to do since he makes some money with this method.