gen 1&2 leggy engines

[Guest]

Merry Christmas to all.

i have a bg5a that i would like to do a single turbo conversion on, now what im wondering is, can exaust manifold intake ect of a gen 1 leggy bolt on ok? as a mate has an engine sitting there with a blowen piston, so i thought it might be a cheap way of doing the conversion.

any help would be great.

thanx

[Shale]

Considering they're pretty similar to the version 2 WRX ones, and said WRX ones have been used on a TT > T conversion before... worth a try

[BC5RA]

Yes it will bolt up no issues.

[Guest]

thanx for that, will give it ago, hope to use gen 1 ecu if can get away with it, till i can afford to upgrade.

what sort of power could i get safely without forging?

[BC5RA]

 Moorza said:

thanx for that, will give it ago, hope to use gen 1 ecu if can get away with it, till i can afford to upgrade.

what sort of power could i get safely without forging?

A broad question, Even forged engines can lunch themselves easily.

Depends on the state of the Engine.

Also depends on how long you expect it to last; How long do you want it to last?

[Guest]

i was hoping to get about 300hp at all four wheels, with boost wound up, but would mostly run low boost for daily driving.

[Guest boostin]

On a stock engine at 300hp, maybe 1 minute, if you're lucky.

[Guest]

oh really, not strong motors then.

[Guest boostin]

200hp yes, 300hp no. 300hp from any stock 2L 4 cyl is asking a lot.

[BC5RA]

 Moorza said:

i was hoping to get about 300hp at all four wheels, with boost wound up, but would mostly run low boost for daily driving.

225kw@wheels takes a bit more than running high boost, any bolt on OE position TD or VF series Turbo will be out of there efficiency range anyway.

The most I would expect a Non STI EJ20 to handle would be 16psi and 160kw@wheels.

Boostin's on the money anyway.

[BC5RA]

 CUDDAS said:

Mine made 176.4kw @wheels, standard ej20g, TDo5h, STA extractors, 3" exhaust, turbosmart 38 w/gate, T/smart e-boost 20psi,

oh & it was an auto in 2nd gear:D at 6500rpm on 4.444 ratio diff

Still going?

[Guest boostin]

Yeah but thats not a stock engine, its been modified. They're talking about turning the boost up to get 300hp.

[wildturkey]

Nice pics......

[BC5RA]

 CUDDAS said:

as far as i'm aware i'm still running a non forged (standard) engine, & safely well i got & put the motor in 6years ago & it still running, although it isn't every day driven, but ive had no major problems,

Some Boxers are not created equal, there are some freak engines around.

I've seen some overheat and run fine when sorted; others not so lucky.

[ReubenH]

I made 176KW also, on stock EJ20R heads, stock V3 sti computer, 3" turbo back exhaust (at the time of the dyno, still had the factory midpipe), and a VF39 running 20psi. I run it on 18psi daily though, and now have the full 3" system.. I can only run that boost cause i got a PBMS built long block (ran 20psi on the dyno to see what it did power wise, and to see if the yellows were up to the task - there were). Wouldn't do that on a factory engine.

180KW at the wheels is actually quite a feeling. tis plenty of power.

Now, a BG5A won't make that much power with it's engine, the EJ20H's don't flow as much, especially the early ones, they are on par with V1/2 WRX, not V3/4 STi. They are far FAR less likely to spit big end bearing out though... All gen 1 legacy single turbo stuff will bolt up, i recomend sticking to V3/4 WRX though.

ECU wise, You have to re-pin the ECU to run a single turbo ECU regardless, so go to the later model 3-plug from the V3/4's, not the early 4-plug from the legacy's and V1/2's. 96-98 Forrester, and some V3 WRX ecu's will run grey top injectors and purple AFM's off the 3-plug, so you don't have to spend the $'s there just yet upgrading to yellows and an orange AFM.

Regarding the difference with all the single turbo stuff between gen 1 legacy, V1/2 wrx, and V3/4 wrx. The exhaust manifold, up-pipe, down pipe etc are all much of a muchness. The difference between them is all in the intake manifolds. Stick with the twin turbo intake manifold mate, they are the same shape as the V3/4 generation, and run the V3/4 gen intercoolers. The difference between gen2 and V3/4 is the bolt points on it, they run a different shaped ICV pipe, don't have the BOV return line underneath (though have the bolt points for one) and they don't have the bolt points for the coil pack setup. But essentially are the same manifold. That said, if you find a V3/4 one for a good price, get it.

Regarding the turbo itself, the gen 1 legacy turbo will have a 90º intake. I recomend selling that, and buying a TD04 (will flow much the same) off a post 96. Will work with the V3/4/gen 2 intake manifold setup.

Um, long post short. gen 1 turbo related stuff works fine, use the stuff your mate has. Stick with the twin turbo intake manifold setup, it's usable for single turbo. Get a turbo off a post 96, and get a 3-plug ECU, not a 4-plug.

[Munkvy]

If your going to the effort of a single turbo conversion - you may as well put an STi motor in at the same time - they are reasonably cheap and if you get a V3/4 one at least you will have the base for making decent power later on.

I went to an STi V3 motor (admittedly its forged and running a Link) with stock heads and made over 200kw at the wheels with only 15psi on a TD05. This is swapping from a factory RS motor that only made 156kw at the same boost, although there was the added advantage of the larger injectors too.

[Guest]

 ReubenH said:

Now, a BG5A won't make that much power with it's engine, the EJ20H's don't flow as much, especially the early ones, they are on par with V1/2 WRX, not V3/4 STi. They are far FAR less likely to spit big end bearing out though... All gen 1 legacy single turbo stuff will bolt up, i recomend sticking to V3/4 WRX though.

I know of a bg5a and a bd5a that both made 180kw atw with the original twin turbos ! So they can flow enough...

As long as an engine does not det then in theory a cast piston will be ok.

Obviously on a turbo engine this doesn't leave alot of margin of safety !

[ReubenH]

I can only assume they had a bit more than factory V3 STi stuff to acheive this. Nothing saying the engine itself can't make more power, but with the same ammount of work, a V3/4 STi engine will yield more.

[BC5RA]

I would rather cut weight from reciprocating engine internals or from the vehicle itself than add more power.

[Guest]

 ReubenH said:

I can only assume they had a bit more than factory V3 STi stuff to acheive this. Nothing saying the engine itself can't make more power, but with the same ammount of work, a V3/4 STi engine will yield more.

Well you did imply a common myth that early twin turbos can't make 180kw which as you know is plenty of power.

Stock engines. heads etc etc

intake, exhaust, turning up the boost - just the usual turbo mods

So yes they can make 180kw... heads are rarely a limiting factor at such low power levels

To be honest the only thing worth keeping on a ver 3/4 Sti engine wise if you want to make good power is the heads.

[funkytown]

 Qwerty said:

To be honest the only thing worth keeping on a ver 3/4 Sti engine wise if you want to make good power is the heads.

truth.. as is my build

[ReubenH]

 Qwerty said:

Well you did imply a common myth that early twin turbos can't make 180kw

It was not my intention to imply that at all, and i have set that straight. What i meant was that with the same ammount of work, it won't acheive the same power as a V3 STi engine..

[Guest]

thanx for that, so the ej20h engine with forged internals will be as strong as an sti engine? because it might be cheaper to streghten the engine i have, rather than buying an sti engine and the putting forged internals in that.

[ReubenH]

If you are just converting to single turbo, you don't need to touch the block at all, it will be fine for your purposes. Single conversions in themselves do not add power, they change the way the power is delivered. Should you convert with STi bits like ECU and injectors, good exhaust and such, you will get a mild performance increase as a bonus, but the engine will still be perfectly fine.