boxerbob

I have been looking at this thread over the years, I have a love for older GM but love my Subaru's. My wife's Forester reminded me of it again because I absolutely hate the engine in hers. I obviously want to know if this thing is still going, but does anyone here know if a Subaru 4EAT can be controlled separately from a GM PCM?

its jsut a matter of sacrificing top end for low end or low end for top end.

 

the supercharger in twincharged ends up like your putting a desk fan on the roof of your car at 70 mph.

 

but guys mine and climber d's are automatic. the stall of the turque converter allows the engine to hop up to the power and let the turbo spool.

 

Yeah, if Grand Nationals with big turbo's can do wheel stands and are kept a 4spd auto the turbo top end must not be hurting them so why would it you. Just may need more converter at some point.

It depends on what you want from your engine too - top power or a nice wide torque curve. The latter is preferred if you want something that's easy to drive, and in many cases you can be faster with such an engine since it's less sensitive to the wrong gear.

 

Roots blowers are only good for low and mid range. Yeah they can make horsepower but tend to lose top end depending on how well built even then turbo's can still do good mid range and better top end. My 98 regal gs with the factory eaton m90 drops off on high end, with factory cam or rockers its pretty pointless to try and go beyond 100mph. Pulls hard in first and second but once i hit 3rd around 97mph it feels like its lacking about 40hp.

Also the gen 3 m90's are also only 50% efficient at 15psi. On a 3800 depending on build for that boost range you'll see high 12's which is intercooled range. 15psi on a decent turbo is low 12's or better.

^ Buicks are crazy heavy....so no surprise there. 10x better/softer ride.

if it was a regal GS it runs around 3600lb factory. stock it'll break 14's. glad to see your swap is running good!

I love that toon, partly because I've been that guy before ...

 

i can't help it myself. Its an uncontrollable urge to add my two cents. I drive a subaru, own a regal gs so this thread called out to me.

its 3.8 not 3800. 3800 is newer 88+ style engine. they have balance shaft and what not.

 

88-95 3800 are quite strong. but have diffrent camshaft head and intake designe.

96-01 have crossbolted mains but powderd metal rods and 1" shorter deck height meaning shorter rods. very strong bottem end weak rods. but will accecpt the same piston as grand national.

 

mine is out of a 87 buick centuary or park avenue and you would know that if you read through the posts !

 

actually the Hot forged powdered rods didn't kick in til around 04 for the L32 code supercharged. their actually pretty strong and reliable but if your looking for more than probably 450-500hp i'd say they wouldn't hold. L67 code ran from 96-03/04 and were just plain old rods.