EJ20TT Questions

[desertsoob]

I am saving up for a EJ20T swap into my dune buggy. I seem to find tons of EJ20TT JDM motors but the EJ20T seems harder to find. My question is, if I strip the twin turbos off and put the offroad header and a single turbo from a EJ20T...would it be the same? All of the TT stuff seems to be a bit much. I am going to use a Megasquirt ECU and trim all of the extra stuff off. WHat do you guys think?

[keltik]

The EJ20T motors are a bit more rare as they were only used in the WRX and some Legacys. EJ20TT's were used in most Legacy GT's, B4's and Blitzens from '90 onwards.

 

The twin turbo is almost identical to the single turbo unit. A common modification here is to bolt on a WRX turbo and exhaust system and throw in a new ECU. The intake manifolds are the same, just the intercooler thats different - and you can even use the same intercooler with minor modification.

 

Also as far as im aware - all the JDM turbo models had hydraulic lash adjusters and quad cams.

[Hotshot]

From what I hear, converting it to single turbo is fairly easy, just plug up the oil and coolant lines that would have gone to the second turbo. I have been asking a lot of questions around on different boards for the swap I am doing, and it seems that the twin turbo engine is very similar to other subaru turbo engines, just with a few overly complicated valves and solenoids to control the sequential operation of the turbos. I do have to admit though, that the idea of a twin turbo dune buggy would be pretty cool.

 

I'm not sure how compatible with USDM ej20 parts they are though. It certainly would be nice if a lot of stuff would just swap between them.

[keltik]

If your running a megaSquirt setup it would actually be pretty easy to keep the sequential turbos. Just run independant boost controllers for each turbo.

 

Then youd need to figure out an RPM activated switch to open/close the exhaust valves to route flow from the small turbo to the big one.

 

The hardest part is sorting out the RPM switch as the factory ECU figures out when to switch based on the TPS and boost pressure inputs.

 

Biggest issue i see is having the 4500rpm valley of death, where the small turbo is unable to produce enough boost while the big turbo winds up - so you lose a LOT of power for a few seconds.

 

The end result if you can pull it off is a unique dune buggy with insane amounts of low down torque, but will rip your nuts off when the big turbo winds up.

 

 

All this is theory btw based on working on a few GT's and stripping the motor from my old one. I had a play round with mine in an attempt to remove the "valley of death".

[desertsoob]

The problem with the TT's is, I would have to build a new exhust and have tons of plumbing. The turbos are in the wrong spot and will interfere with my CV's and such. Not to mention, a car that sees lots of steep dunes does not need a dead spot!

If I strip it down and go with a single and header, it should work good. My goal is lots of power and try to keep it very simple. Basically, just wondering if the engine was the same. I dont want something that will be hard to get belts and parts for. I am trying to do something like this.

[keltik]

Yup the block is identical to the single turbo unit. All parts are interchangeable with other EJ motors except for the exhaust as the DOHC heads have a different shaped exhaust ports.