Limits on a 4A

[Stealer Of Souls]

Hey...

Okay. I'm thinking of starting the engine build for my car.
The plan:
4AGTZE
225kW (300hp) at the fly.
Ooodles of low down power for the daily haul, with good top end. Doesn't need to blow your socks off, just good.
Will also have a 50-75hp shot of NOS and be able to dial up the boost for a short period (15-30secs???) for a total of around 300kW (400hp) at the fly.

The Car:
1986 AE85.5 Levin

The idea:
I want to use this car as an all purpose vehicle. So all forms of track/competition. PLUS I want to daily drive it. So, it needs to be friendly. I want it to be competitive, but it doesn't have to be a class winner. As long as it can stick with the pack and scare the crap out of unsuspecting people on the street.

The challenge:
Twin charge is the first challenge. One that I'm looking forward to try and best.
But in the short term I'm just gonna run a 4AGTE.

From those with experience...
What turbo?
What's the most a 4A is gonna handle? Can I make 225kW reliably? Will it handle a peak of 300kW for around 30secs?
Can I do all this while retaining a CR of around 9.5:1, or even upto 10:1? Or am I kidding myself?

[Drifter4ag]

bluetop will handle it
4agze will definitly handle it
nite special t3/4 will see you there with no more than 18psi boost on 9.5:1
dont worry about the nos you wont need it.

[EVLGTZ]

Yep agree with matts comments. Just make sure ya get yaself a decent ecu (and tuner) to keep it all in check.

I personally wouldnt waste my time going for the twin charge setup but hey its up to you. As long as ya got plenty of cash and pateince then go for it.

[Stealer Of Souls]

Coool....
And here I was thinking I was gonna get heaps of posts say...
I hope you've got deeeep pockets.
or
It can't be done with reliable results...

Cheers Matt and Jade.


But NOS is fun...
Do you have any suggestions/hints on what I will need. I'm trying to decide whether or not to start stock piling parts or just wait till later on and do it all in one hit.
Was thinking on the way in to work, should I start by building a good NA motor (with turbo change in mind) and then plonk a turbo on the side, or should i just go turbo from word go.
So what I mean is...
Build a 130kW NA motor and then plonk a turbo on the side and work out the tuning/bugs.
Or build go straight along and try building a 225kW turbo from the onset?


I'm gonna try twin charge eventually, just to be a bit different. I am very patient. And i can save the money. So I'm gonna give it a try. If it's really that hard/pointless then I'll scrap the project, but not till I've given it a good go.

[Monsterbishi]

just build a turbo motor right from the get-go, track down a silvertop, throw some gze pistons in, add turbo, a sneeze of engine-management, and you'll be good to go.

[Drifter4ag]

you dont need to build a fancy engine
run a late model ze with a .8mm gasket or shaved head and standard gasket. Standard engine will see ya over 200kws @wheels if rebuilt just to factory spec.
Its alot easier than people make out
for 3-4k you can have 200kw@wheels reliable

[Mr Revhead]

20v with ze pistons isnt a fancy motor... and for the price of a 4agze you can buy a 20v and rebuild it...

2nd hand 4agze vs rebuilt 20v ze.....

[Stealer Of Souls]

What if I wanted to build a fancy motor? Would it be a good idea?

I'm guessing the .8mm gasket/shaved head & std gasket is to up CR?

3-4k... sounds nice...

Is a 20V head a good idea for forced induction head? Rumour has it, it's not. But engine drive theory says it should be.

What benefits are there in doing things like .5mm boring of cylinders? What's the max I could bore out a 4A?
Is it possible to get cranks made up? Like to say 78mm stroke?

I'm just considering all my options and things that I thought I might like to do.
I would like to use less boost in the final design than 18psi. But it all depends on whether or not these options were all that pointful to my desired outcome. That outcome being a flat as possible torque curve all the way from idle up....

[spencer]

stroker crank for a 4age would have to be custom made at big $$ unless you track down an hks 5age kit bit will also be big $$. As peole have stated find a silvertop and put some brand new late ze pistons in it and go. Dont worry about building an NA motor first thats a bad move

[Caveman]

Just work on breathing keeping in mind expansion for a turbo. Flow the head and manifold. Once you turbo a car all the restrictions multiply so a good flow is essential for big reliable power.

[suberimakuri]

sounds like one of those posts about the motor that never eventuates.

stuff rebuilding anything, getting a good runner is where it's at.
changing headgasket is easy and is one major out of the way.

Then, as said before, plenty of fuel and a good sized turbo.

at least with a 16v head you have easy manifold options.


I guess it comes down to whether you want a setup that works, function first....... or you want some fancy pants motor that has a different rocker cover.

I'd like to see the dyno graphs for a turbo 20v.
as for turbo 16v, we've got a heap on our site.

not everyone puts up these things on internet, but i like to think the proof is in the peanut butter.

[Al]

I'd like to see the dyno graphs for a turbo 20v.
as for turbo 16v, we've got a heap on our site.

Ask matt dunn for a copy of his or mister2's

[suberimakuri]

matt dunns has been in nzpc. good work. keep 'em coming. then run 'em on the track.

[EVLGTZ]

I'd like to see the dyno graphs for a turbo 20v.
as for turbo 16v, we've got a heap on our site.

not everyone puts up these things on internet, but i like to think the proof is in the peanut butter.

I got a few more 16v ones for ya if ya like Karl

[Stealer Of Souls]

sounds like one of those posts about the motor that never eventuates

Tee hee.. You don't know me very well...
The motor will happen. It just depends whether it will be a plain turbo setup or a "something different" twincharge special!
After all I've already spent in the order of 24k on the car...

And before you go WTF! I was unlucky with the car. If it can wear out/break, it has worn out/broken. I'm sure I must have replaced just about everything in the car with something new and usually something upgraded... So the cost of replacing just about everything in an AE85.5/6/5 is around 15k....
God that was a painful lesson. But at least I know I won't be break too much for the next year or two while I build an engine. Man I need a better job....

I'd like to see the dyno graphs for a turbo 20v.
as for turbo 16v, we've got a heap on our site.

I'd like to see some 20v turbos too. If you find/get a hold of some I'd like to see them.
It was interesting to look at the dyno charts on your site. Gives quite a good insite in to things.
Makes me really wanna perfect a good twincharge setup...


But back to things....
How far can you bore out a 4A?

[suberimakuri]

heh.. yeah I know Jade... would be good for site actually if you want.

cool, i hope you're going hilux and w box, or similar for this build then if you break stuff.

[Stealer Of Souls]

I'm considering options on the diff/box.
I want to keep weight down and I'm prepared to spend some money if need be.
I don't know about diff at all, but I'm not keen on adding all the unsprung weight of a hliux end. I was wondering if I could get a Cusco/TRD/Kaaz or any aftermarket diff to survive, bearing in mind I'm not planning to drift, racing with 300hp. I'm also needing to inspect if you can get strong enough half shafts to do the job.

As for the box I'm thining of going down the road of custom internal T50. Dog box, specified ratios. Again, don't really know if it will be able to handle the jandle. But not looking at that right now. Got a AE86 rear with a brand new TRD 2 way. Once I've got an engine I'm gonna invest in a T50 to replace my K50 when it blows up...

[suberimakuri]

maybe late model ae86 diff would be ok........ but i don't trust it.

to be honest, the thought of racing with 300 hp with T gear seems a waste of time to me.
extra weight or not.... just the luxury of being able to chop gears quick or having unbreakable gear seems slightly more important to me.
Especially when you're launching with slicks and the 1->2 gear change is not easy on a T50.

though, i guess it depends on what class you're in.

[Drifter4ag]

bah ..its not even that heavy ..
my piece weighs 960kg full interior and its armed to the teeth.
T50 is a waste of time
T series rear end is a waste of time if going over 200ps
you will snap axles every other day
the extra weight is marginal - maybe 30kg .. stuff all really .. more weight in the back evens the dist out on the car

[Stealer Of Souls]

the extra weight is marginal - maybe 30kg .. stuff all really .. more weight in the back evens the dist out on the car

How much of that is in the rear end. I would agree that 30kgs is squat all, but if it's all unsprung then for the sort of work i wanna put the car through it's best avoided.

And weight dist for general performance is best at about 53/47-55/45, cause then when on the gas the weight shift moves it more toward 50/50. The supposed optimum. Anyways that's a bit of a moot point since my car has odd bits everywhere my weight dist is probably closer to 50/50 anyway...