4AGTE questions

[Bagpuss]

Hi guys and girls,

So my long term plans have always been to get a decent amount of power in my corolla, and I've had a fair few ideas as to how I'll achieve it, which have been narrowed down to either a 1UZ or turbocharging my current 4AGE.

The 1UZ swap is pretty self explanatory so I won't bother including that here, but turbocharging my 4AGE has left me with a few questions. Firstly how much boost can you safely run on the stock bigport internals? Also what is the maximum power the t50 gearbox can handle before giving up the ghost? The final question, and probably the most important one, is how much power could I see from the setup before needing forged internals putting in?

The basic plan for the build is to run a nissan t25 turbo on the typical HKS manifold, using the stock intake hooked up to a large intercooler. I will probably need larger injectors and I'm still debating which ecu I would use if I went down this route. With regards to the forged internals I have enough money to buy them, but if I was going down this route I'd prefer to try building my own engine, I don't profess to be a mechanic and I've never built and engine before so could that be a bit too ambitious?

Cheers for the replies, any and all opinions are appreciated!

[Tony N]

My advice would be to save yourself a whole load of hassle and start with a 4A-GZE if you want to run boost. They can take huge amounts of boost so it's not really worth considering forged pistons and rods particularly with an 86 drive-train.

4A-GE pistons are too weak for prolonged boost even at low levels, I had 3 crack in the ring lands over 4 years and have now moved to a GZE bottom-end as I had enough of swapping them. Even standard engines fail like this to give you an idea of how bad they are.

The T50 thing comes down to how you drive it, if you continuously launch it with grippy tyres it will break, but if you drive it sympathetically then they will last. Mine finally let go at Pod in feb with a 3rd gear clutch kick but it's had 5 years of drifting with boost so it did ok really. I've had a W58 waiting to go in for 4 years as I didn't expect the T50 to last this long so I'm half way through the conversion for that now.

[Bagpuss]

I do drive my car quite hard, I recently had to swap my last (stock) engine out as the big end bearings failed on me, so maybe this conversion isn't worth doing! The main advantage vs swapping for the v8 was price, but by the time I factor in the costs of another new engine, ecu and setup the price gap is negligible.

Thanks for the advice though, am I right in thinking the 4AGZE also uses the stronger 7 rib block?

[Tony N]

Yeah 7 rib block and larger big and small end bearings. The later ones have the small port head and oil squirters too. 4A-GTEs drive fricking ace but it's probably more cost effective to do a dirty SR conversion

[Chaycore]

wash your mouth out Tony! Im going to change SR in the forum so it gets automatically replaced with *I cant drive a 4age so cheat using dirty nissan power*

[Tony N]

Think Hux might have something to say about that

[Bagpuss]

Nooooo don't think I could bring myself to put an SR in it! Besides everyone knows the CA18 is far cooler

I'm still trying to figure out prices for getting a 4agte set up, the main reason I looked in to this option was various sources online quoting power figures of 250-300whp using a t28 turbo and a good map, how realistic are these numbers? If those figures aren't reliably obtainable I'll stick with the v8 option as reliable power is a requirement.

[Tony N]

I believe a T28 is good for around 300hp at the flywheel depending on how far you want to push it.

It depends what you're after, the nice thing about a 4A-GTE is they drive and sound (from the drivers seat anyway) the same as a regular 4A but with more power.

But much as I hate to say it, I think if you're looking for 200-300hp then slinging in a dirty SR is the way to go as you have the complete set-up - engine, gearbox, turbo, ECU + harness. The problem with CAs is they're all much older and if you're going to the trouble of doing a conversion you should use the latest available.

I've not got any experience with V8 conversions but I would say it's a LOT more work. Bigger mounts, two exhausts, bigger transmission, moving stuff that fouls, more wiring plus you won't get away running an 86 axle so you'd need to change that too. Just my two pence...

[Bagpuss]

If I went the v8 route I'd be getting Nev at driftmoto to do the conversion simply for the amount of work involved. I was wondering about the rear axle, I was hoping I could get away with it as I have a fully rebuilt rear end, with a cusco 2way, cusco drive shafts, 4.7 pinion gear, solid crush sleeve and all new bearings.

The SR swap doesn't really interest me as the amount of fabrication involved in doing the conversion would be similar to doing the v8 swap, new transmission tunnel, new mounts etc. the attraction towards the 4AGTE was that I could get away with using the same engine mounts and keep the t50 transmission, making it much easier for someone like me to achieve (I don't trust my welding when it comes to stuff like engine mounts).

In terms of what I'm after ideally I'd want to achieve at least 250hp and maintain the high reliability level, I'm not a professional racer and as a result I can get a bit heavy handed with it at times

[Tony N]

Yeah, I don't think the axle would live with big capacity torque, mine is pretty noisy even with moderate boost levels!

I'm not certain but I'm pretty sure the Nissan box will fit an 86 tunnel as they're quite skinny. Hux is the man to speak to though.