7AFE vs 4AZGE?

[Shifty]

Hey guys

As per the other thread I recently purchased an AE82. If and when it dies, or I get itchy feet, the plan is to do an upgrade of some description.

The intention would be to leave it prettymuch standard - stock exhaust etc - and used as a street car only. I'm consdering these engines

89-91 or 91-95 4AGZE 165/170hp@6400 152lb-ft@4400 81x77 8.9:1 (Jap AE92/AE101)
93-98 7A-FE 115hp@5600 110lb-ft@2800 81x85.5 9.5:1 (Local)

The fairly obvious choice would be the 4AZGE although considering this from the viewpoint that the engine will remain standard and will only be used as a street car with no real performance aspirations other than being nice to drive and reasonable on fuel, would the low-revving 7AFE be a better choice?

[Hiro]

Is it currently a 4AGE or 4AC?
You say " will only be used as a street car with no real performance aspirations other than being nice to drive and reasonable on fuel", yet you're looking at a 4AGZE.....

Best bet (if it's already a twinky) is to just replace the engine with a fresh bigport, which will provide just about as much thrust as a 7AFE without the conversion hassles, be good on fuel, and still give you a smile every time you take it to redline.

Remember, a GZE putting out 120-odd kw at the fly, going into a roughly 900kg FWD short wheelbase car makes for a lot more than "no real performance aspirations".


And this comes from someone who owns both 4AGE- and 7AFE-powered cars

[Shifty]

Is it currently a 4AGE or 4AC?
You say " will only be used as a street car with no real performance aspirations other than being nice to drive and reasonable on fuel", yet you're looking at a 4AGZE.....

Best bet (if it's already a twinky) is to just replace the engine with a fresh bigport, which will provide just about as much thrust as a 7AFE without the conversion hassles, be good on fuel, and still give you a smile every time you take it to redline.

Remember, a GZE putting out 120-odd kw at the fly, going into a roughly 900kg FWD short wheelbase car makes for a lot more than "no real performance aspirations".

And this comes from someone who owns both 4AGE- and 7AFE-powered cars

The car is an original AE82 Twin Cam with a fresh 86kw 4AGE in it (old one died, so low km one purchased and rebuilt before being fitted).

When I say "no real performance aspirations" I mean that unlike most people on these forums I know that anything this side of 300hp at the wheels is slow, but that I just want something a litle more liveable and interesting.

I bought the Twin Cam as I have a soft spot for them after a mate had one many years ago and I always loved getting around in it, and they're a pretty hot little car if done right.

For those who don't know the lingo, what's a 'bigport'... is that a 100kw 4age? I drove a mate's 100kw GTi and it was a really punchy little car, actually it was a fucking hoot to drive. That engine in an AE82 would be plenty of fun, although I still wonder if a 20v wouldn't be a better/more sensible option than that.

A 4AGZE would be ideal but prices seem to vary wildly (anywhere from a few hundred bucks, to three grand) and I'd be concerned about buying a shit old engine to replace my shit old engine...

[Shifty]

Actually what about a 7AFE with the 4AZGE setup on it... is it a simple swap? Is the GE head a major benefit when you have forced induction and the extra 200cc?

[Shifty]

Ok well looks like a 7AFE is poo for forced induction... crap rods etc.

So back to my earlier questions:

* is a 'bigport' the 100kw engine?
* how does a 20v compare to these? I can just get a newer 20v a lot easier than I can get a good 100kw engine.

[4agerolla]

The bigport is the motor you have in your car now (early 4age).. the 100kw is a small port (later 4age).

Ive never driven a 20v powered car, but Id say it would be superior in all areas if the two motors were left stock standard

[X kyle X]

I have owned and driven hard all 3, biport 88kw, smallport 100kw and the 20v silvertop 119kw

And honestly the smallport was the best engine, there is NO difference between the 20v and the smallport 16v in speed/acceleration

And the parts for 16v engines are easier to come by

[mullett]

For a street car, 4AGZE WINS. I'm biased, because I loved mine so much, but I think they're a perfect street motor. Bulk torque, instant response, and in a 900kg car, it would certainly move. To me, the bottom-end of the GZE makes it a clear winner for a daily driven car, but you're going to have to budget many more dollars. A nice smallport will probably only set you back 1k or so, a GZE will be 3+ by the time you've installed, re-wired, plumbed intercooler, etc etc.

If your motor is a fresh rebuild, then the obvious solution is a low-boost turbo...

-RM.

[X kyle X]

^^ i agree with mullet..

if you want to get out of it cheaply.. get a manifold (the 20v one from ebay is the go for cheapness and only requires you to slot the end bolt holes for fitment and is about $299 i think))

buy a second hand t25/t28 from a 180sx (can be had for like $250 from egay again)

buy some aftermarket management (mircotec or other cheap ECU $1000)

get some water and oil lines for it (simple job can tee into the existing water lines and oil feed) buy/make a modified sump (with the oil drain bung in it) probs take 1 hour or so to make it up...

get a good tune..

run like 8 psi..

ownage!!

[Draven]

I know that anything this side of 300hp at the wheels is slow,

in a car that's under a ton? 300hp@wheels is going to be one hell of a handful!

[X kyle X]

yeh 300hp at the wheels would be mghty quick in a 900kg car like a ae82...

[mullett]

^^ i agree with mullet..

if you want to get out of it cheaply.. get a manifold (the 20v one from ebay is the go for cheapness and only requires you to slot the end bolt holes for fitment and is about $299 i think))

buy a second hand t25/t28 from a 180sx (can be had for like $250 from egay again)

buy some aftermarket management (mircotec or other cheap ECU $1000)

get some water and oil lines for it (simple job can tee into the existing water lines and oil feed) buy/make a modified sump (with the oil drain bung in it) probs take 1 hour or so to make it up...

get a good tune..

run like 8 psi..

ownage!!

I agree with that, the only thing I'd change is the management. Microtec (or any other) cheap ECU will still cost 2k by the time it's fitted and tuned, and tend to have pretty average control of the 'niceties' like cold start, cruise AFRs, A/C idle up etc etc.

For such a mild turbo install, I'd go for a set of GZE injectors and an interceptor that can compensate the whole map for the larger injectors, and compensate for the boost with more fuel. I think that the bigport had an AFM? In that case tuning will be pretty easy AFAIK. This will be MUCH easier to wire up, and should cost less than $800 fitted and tuned for something nice. A 2nd hand SAFC and a DIY wiring job could see the whole lot done and tuned for $300.

For cheap T25 turbos, head over to one of the silvia forums, like silviawa, they're often going for $100 or so. I've got one or two at home, but I can't be totally sure of their condition, so I'm not going to sell them to anyone except as a dummy

A friend recently did this for his MX5, the whole install (including an exhaust) cost just under 1k, not including the ECU.

-RM.

[Shifty]

My last bike was 218kg & 174rwhp... sold that to buy a new bike and chase 200rwhp with a modest turbo setup... so yeah not interested in fucking with turbos, management, etc, for a cheap runablout/weekender. I just want something 100% stock & reliable that's nice to drive and can't be defected.

As mentioned the 4AGE in there is a low k motor that's been fully rebuilt (rings, bearings, etc) so there's absolutely nothing wrong with it and it goes fine, it just feels slow to someone used to effortless acceleration.

Seems like a 4AGZE is the go.

[Mr Revhead]

keep it original! these are geting rare!

the 4agze is a good option, use the stock NA gear box for awesome acceleration

however... the 7afe will probably be cheaper to buy, maintain and run.
and will be better to drive around town. if i was building a car for daily city driving, i would go with the 7afe

[trdee]

.........I just want something 100% stock & reliable that's nice to drive and can't be defected..............

............Seems like a 4AGZE is the go..........

These two lines contradict each other for every point you made. It will not be 100% stock and reliable, and it will need an engineer's certificate. Keep the stock bigport. If you want a faster car, then buy a faster car. It will work out cheaper, less hassle, and will be more reliable.

[mullett]

Agreed, I wouldn't take this on as a second project. That said, lots of GZE powered twinkies come up second hand...maybe hold out for one of them, it'll certainly be cheaper and easier.

-RM.