Jump to content
Ultimate Subaru Message Board

Recommended Posts

Hi,

 

I bought an open wheeler with a ea81 motor (1.8 NA 1985ish) and 4spd gearbox in it. The motor is sad and old (read 50bhp)

 

I have an EJ20 turbo 1996 wrx motor that has been rebuilt with new bearings/rings/gasket/etc. The internals remain the same. I have a new fuel and spark system sitting there I was going to put on a Supra (now sold): 

-ID1000cc

-Aeromotive 1000 

-top feed rail and lines to suit

-turbosmart fpr3000

-B&W CDI

-OEM Supra coils

 

I want to run the EJ20 on Methanol (with additives). I'm new to the boxer motor and want to know what hp I should be looking for on stock internals with a good chance at it all holding together. I dont know what turbo I should be running, and I was hoping you guys with experience could help me out. 

 

Any help would be greatly appreciated. 

Link to comment
Share on other sites

If your looking for that much power (I don't see why, but that's not my concern) your going to want to use an EZ motor (the oposing six cylinder) much heavier duty internals and a bigger cid.

I just don't see an ej20 ever being able to put out that much power

Link to comment
Share on other sites

You'd need a GTX2871 or GTX2876 to hit that power level with a single turbo and NOT be a lag car that does absolutely nothing until 3-4k rpm. OR you can run 2 smaller turbos like twin GT2554 or even better a twin GT17xx setup at moderate boost levels. The GT2554 at around 14 psi each would get you there. The GT17 turbo at around 10 psi each would be 400 hp, and the lag wouldn't be bad. But you'll need a tunable ECM to account for fuel, bigger injectors, MAP sensor, boost, timing retard under boost, timing advance, etc. If you feel up to it, you can try a carb with the turbos, but it needs to be able to accept boost and it MUST be professionally jetted and adjusted. Can also try a super charger like the Mustangs run as there wouldn't be lag from that and it'd make enough hp to be fun. If none of this is your cup of tea, try a T5 Saab engine and read up on their tuning software as people have reversed it, and those engines can tolerate that power level on stock internals. The tuning software has a plethora of preconfigured "safe" tunes that also has a user friendly interface with drop down boxes to select say a GT2871 turbo, 630cc injectors, a Walbro fuel pump, and be up and running. Though I'll have to warn you, there's some homework on your part needed to dump the factory .bin files and flash the donor ECM with it as the ECM's are keyed to the car. Otherwise, go with a NA Ford 351w with a set of heads and a small cam, or look for a modern GM V8 and throw a carb on it and go.

Link to comment
Share on other sites

Thanks for all your comments. I really want to stick with the EJ20 because it's what I have at the moment and upgrading in stages suits my budget. 

Methanol should help it get to higher hp, though it doesnt reduce stress/load on the engine.

 

I see people on the forum get to 300-350bhp without too many mods. Is that where the limit is on the internals? (I know nothing is guaranteed). 

Link to comment
Share on other sites

Thanks for all your comments. I really want to stick with the EJ20 because it's what I have at the moment and upgrading in stages suits my budget. 

 

Methanol should help it get to higher hp, though it doesnt reduce stress/load on the engine.

 

I see people on the forum get to 300-350bhp without too many mods. Is that where the limit is on the internals? (I know nothing is guaranteed). 

 

Generally speaking, I've seen a LOT of guys stick, say a Holset HX35 on a FWD 4 cyl. then brag how they are making 400+ hp at the wheels. The problem is, that's a peak HP rating at redline, which we'll say is 6500 rpm for the sake of argument. Now, if you were to look at a dyno graph of that engine, it'll make 65hp off idle, 100 hp at 1900 rpm, 120 hp at 2200 rpm, 150 hp at 3500 rpm, then at 3700 rpm when the turbo is finally up and moving, the number jumps to 250 hp, and finally at 6500 rpm it's making 410 hp. While it's "technically" a 410 hp engine and great for forum bragging rights, in a 3k pound car, it'll be lucky to hit a mid 12 in the 1/4 mile. IF the engine had a higher average HP/TQ, which means it made more HP/TQ below 2000 rpm, like a NA V8 does, it'd probably be in the low 11's assuming it hooked. A lot of those same guys will defend their decision of sticking an incorrect turbine housing and oversized turbine wheel on (by turbine I'm referring to the exhaust-side of the turbo) by saying it's not as hard on the engine since you aren't making ungodly torque off-idle and throughout the low revs. While that's technically true, since the engine is barely making stock NA HP levels under 3500 rpm, and is already moving above 3500 rpm, it makes for a fairly slow car. 260 hp V8 can get you a 13 flat if you weigh around 2700 pounds. The early 00's Trans Ams could run a 13 flat on street tires with only 300 hp. Put that same 300 hp V8 in a 2700 pound car and you are deep in the 12's, with a 110 hp LESS than the guy running a wrong a turbo that's playing catch up the entire race and already has the engine fairly maxed out. Now, if the same guy stuck say a GTX2871 on the car (a GT2571 can be made by custom matching of wheels, and would allow for more low-end power), I think high 11's would be reasonable in a 3200 pound body, with very low 11's at 2700 pounds, which is nearly HALF the HP of these Hellcat Dodges popping up. Do you see what I'm getting at? Don't focus on some pointless "peak" HP number that's only good for bragging in forums "My 4cyl. makes 450 hp from a Holset HX40" but barely runs a 12.4 in the 1/4. Whereas a 320 hp engine making peak torque as early as possible and holding it as long as possible, while making say 180 hp at 2k rpm, 250 at 3600 rpm, and 300 and higher the rest of the way up to redline will make for a much more stout car. Unless you are aiming for the standing mile run, 7k rpms and that oversized turbo won't be very fun. And since we are talking about some sort of buggy car, you want as much power off the line as possible and I'd even say LESS of a redline with a cam that favors off the line performance and midrange powerband and it'll scoot like a cat with a firecracker up it's @ss

  • Like 1
Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

 Share

×
×
  • Create New...