Jump to content
Ultimate Subaru Message Board

NA EA82 build


WJM
 Share

Recommended Posts

Here is what I was thinking....

 

EA82 block. 11:1 compression (the limit on pump gas) Pistons/rods. big NA delta cams using nearly stock drivetrain with stock 6500 rpm redline.

 

Spyder lower intake peice...with dual carbs sitting on the top of each cyl bank. Standard vac controlled dizzy, and no electronics at all other than ignition and information return to driver (temps/pressures/RPMs/speed)

 

Lite flywheel, and pullys. PS and alt. with dual v belts....attached to the 2wd xt turbo 5spd trans (best gearing and 5th is tall! 140mph!) with the XT6 clutch and pressure plate. FF configuration....in an 85-86 2WD 5 spd DL sedan (2100 lbs!!!!)...and strip it down...(WOW! Less weight now!)

 

160 hp? Power when the foot is put down. no lag! And that lite chassis...fastAr than WRX! Almost as fast as STi (if said DL is 1800 lbs after strippage)

Link to comment
Share on other sites

Definitely intriguing. I think the biggest problem is going to be detonation. With 11:1 compression, you'd definitely be pushing it, and with my delta cams in it wants a lot more timing to have a decent idle and make any power, which is also going to push it closer to the detonation threshold.

 

I know there's a way to engineer around any problem, it just might get frightfully expensive. The aircooled VW guys have done it, but they've actually got some aftermarket support. Their engines also seem a bit more prone to blowing up:drunk: .

Link to comment
Share on other sites

Definitely intriguing. I think the biggest problem is going to be detonation. With 11:1 compression, you'd definitely be pushing it, and with my delta cams in it wants a lot more timing to have a decent idle and make any power, which is also going to push it closer to the detonation threshold.

 

I know there's a way to engineer around any problem, it just might get frightfully expensive. The aircooled VW guys have done it, but they've actually got some aftermarket support. Their engines also seem a bit more prone to blowing up:drunk: .

great idea!!! that would be a sweet car.

what about water injection? a friend of mine, (subaru master mech.) used to race BMW 2002's and NA's and he had water injection on them to keep the detonation away. he claimed more power from the water injection also...he has not dyno sheet to prove it just the "seat of the pants dyno" aka "butt dyno"

 

Richard

Link to comment
Share on other sites

11:1 as statically measured, or effective? (Many race engines can run higher CR because their valve overlap reduces the effective CR... they actually NEED a higher static CR.)

 

Also, I would think that if you really want to control detonation you are going to need some engine management. EFI can hold the mixtures a lot tighter than a carb, and the stock disty's timing can wander all over the place (not so much if less worn than mine! :grin:).

 

Or just rev the snot out of it and forget about detonation.

 

Sounds like fun. I once rode in a 750lb (empty) car with 120+hp engine on an auto-x course. WOW!!!

Link to comment
Share on other sites

im not worried about det on a carb engine. Plus i have new insights on det on FI EA82s...

 

11:1 static compression.

 

I would still wonder about detonation. I've had 4 engine configurations in my car, and they've all flirted with detonation to some degree.

 

1. Bone stock carbed ea82 with hitachi: running 87 would detonate under heavy load/high temperature conditions. 91 octane, the highest available at the pump here would give better fuel economy and performance. Ignition timing adjustment made a little difference, but not a terrible lot.

 

2. Same engine with Weber carb:Similar results. Advanced the timing a little more in accordance with directions from Weber (ran better and made more power). Seemed to prefer 91 to a greater degree.

 

3. Stock engine with Delta cams and Weber carb: Pretty much had to run at least 89 to prevent detonation under relatively light loads. With these mods, even more timing was needed to make it run well, so it started to become a battle.

 

4. SPFI shortblock, Delta cams, Weber carb: Higher compression made detonation an issue for this engine. Timing had to be retarded compared to the previous configuration to keep detonation under control even with light loads running somewhere between 89 and 91 octane.

 

Now, I know for a fact that something just ain't right with my Weber. That could be a major factor in this, but since even with a completely stock setup including carb I saw some detonation, I would rule that out as the cause.

 

I also tend to hear a lot of detonation-type noises coming from other carbed subarus during similar situations. Although the turbo engines tend to have more of a problem for odvious reasons, it's still there in the carbed motors.

Link to comment
Share on other sites

Bring the piston to head clerance to a minimum (.030 or so at RPMs below 7000) as a primary means of increasing CR and you'll get surprisingly good detonation resistance.

 

I'm running 11.2:1 on a 4 valve motor (stock 9.5:1) on 90 octane with more timing and no detonation. Stock pistons, stock cams...did it by reducing piston->head from .051" to .036"...the 2 valve chamber should take even better to such a mod as it has more quench area (I'm assuming...I've never had the heads off my EA82).

Link to comment
Share on other sites

Here is what I was thinking....

160 hp? Power when the foot is put down. no lag! And that lite chassis...fastAr than WRX! Almost as fast as STi (if said DL is 1800 lbs after strippage)

Ram Performance

"130-140HP RAM Dual Port Engine

This engine has all the goodies of our MPEFI engine but is offered in throttle body or carb instead of MPEFI.

Your Best choice for reliable power and simplicity!

$6495.00"

 

http://www.ramengines.com/_wsn/page2.html

Link to comment
Share on other sites

damnit dude, you make posts like this just to get flamed huh?

if a turbo sube has trouble making that amount of hp with mods, why would na do it?

 

how do you think your gonna get to 1800 lbs, my hatch is 2100 with an almost empty gas tank, and is as stripped as you can get. are you going off of a door sticker, or what you have read somewhere?

 

 

 

at least somebody is thinking like they should about these delta cams. you gotta run high rump roast static compression to actualy have desent compression when the motor is running. those cams bleed off alot more compression than the stock ones. so your 9;1 engine would be like 8.5:1, maybe worse.

Link to comment
Share on other sites

... at least somebody is thinking like they should about these delta cams.
Uh, Thanks!, I think... :-\ :)

 

... those cams bleed off alot more compression than the stock ones. so your 9;1 engine would be like 8.5:1, maybe worse.
Don't know the numbers for the Delta cams in question, but "full race" profiles of old were known to reduce effective CR by 1.5-2, and "street and strip" by around 1.0
Link to comment
Share on other sites

damnit dude, you make posts like this just to get flamed huh?

 

only by you.

 

if a turbo sube has trouble making that amount of hp with mods, why would na do it?

 

on stock internals and cams I am making 160-180 range. Its no trouble...on STOCK boost too.

 

why would NA do it? Because it can. proper air flow in and out of one of these engines NA with proper timing and fuel tuning with the compression and cams will get this engine to 160 na ponies. At this point, the suspension on the car is so good I dont really need any more than 160...but id like to ahve 160 when i put my foot down, not a sec or two later. If I had the $, I would have an EA82T putting out 400 hp like those rally guys in canada have done back in the early 90's. Yes, FOUR HUNDRED. Either way, i would be happy with a 220-240 hp EA82T, and those WILL hold together just fine every day for quite a while...its just a matter of getting a different turbo, exhaust and playing with the ecu and boost control some more.

 

how do you think your gonna get to 1800 lbs, my hatch is 2100 with an almost empty gas tank, and is as stripped as you can get. are you going off of a door sticker, or what you have read somewhere?

 

2175 lbs for a 1986 DL sedan 5 spd 2wd. That is stright from section one of the FSM for 1986. I stripped out atleast 300-400 lbs of mess from my RX coupe...a DL might have less, but it will still have about 300 lbs worth of stuff to get rid of. That and a AL racing seat and some light weight body panels will do wonders in reducing weight.

 

at least somebody is thinking like they should about these delta cams. you gotta run high rump roast static compression to actualy have desent compression when the motor is running. those cams bleed off alot more compression than the stock ones. so your 9;1 engine would be like 8.5:1, maybe worse.

 

I do not dissagree nor agree. All i know is that I am in search of 11:1 static, as that is the limit on pump fuel.

Link to comment
Share on other sites

its just that you talk so much about how cool your stuff is going to be. i have yet to see you post any dyno numbers.

 

how is it that a 1.8 honda motor with vtec can produce 170? technology. not knowhow.

 

take your car to a scale and post how much it weighs, fsm is useless for this.

 

making a new post once a month, boasting about how fast your car is going to be only impresses the new board members and peepl who believe you. the proof is in the dyno sheet, and 1/4 mile times.

Link to comment
Share on other sites

making a new post once a month, boasting about how fast your car is going to be only impresses the new board members and peepl who believe you. the proof is in the dyno sheet, and 1/4 mile times.

 

You have a good point!

 

I'm not even thinking about going to the dragstrip until I put some better numbers down on the dyno. The dyno doesn't tell everything but it says a lot about what you can expect of your car. I'm looking forward to sharing my progress with the rest of you folks as I'm sure there are others that feel the same.

Link to comment
Share on other sites

Please sign in to comment

You will be able to leave a comment after signing in



Sign In Now
 Share

×
×
  • Create New...