63viking

Power enhancement ideas

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20 minutes ago, Barney Eaton said:

how much could you get out of the Reatta by modifying the timing, injectors and transmission shift points?

 

You can very easily upgrade an LN3 and an L27 to tear up their transmissions. The L67 was Factory coupled with an SC, but only after some major tweaking. The automatic transmission has always been the weakest link. Higher pressure pump, adjustable regulator, a remapped ECM PROM, and larger injectors could easily snap the internals of a plain OEM TH440/4T60 ME9 on an '88-'89 Reatta. 

 

The Series I Supercharged engine went through many internal changes and the horsepower changed rapidly between the time it was introduced and the time that the Series II L36 was introduced. The M62 supercharger was manufactured by Eaton, exclusively for the GM 3800 engine. HP was rated at 205 for 1991-1993 engines (models vary), and 225 for 1994-1995 engines. Some of the additional horsepower for 1994-95 engines was gained by using epoxy (not Teflon as commonly believed) coated supercharger rotors to improve efficiency, and a larger supercharger inlet and throttle body. The 1994-1995 utilized a 2.85-inch (72.4 mm) pulley versus the 2.55-inch (64.8 mm) pulley used on the 91-93 supercharger.
 
Applications:
1991–1995:
Buick Park Avenue Ultra
1992–1995:
Oldsmobile Eighty-Eight LS (opt), LSS (opt)
Oldsmobile Ninety-Eight Regency Elite (opt), Touring Sedan
Pontiac Bonneville SE with H4U RPO, not badged - SLE (opt. SC package), SSE (opt) & SSEi
1995 Only:
Buick Riviera(Opt)
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2 hours ago, Ronnie said:

 

Sorta like a Paxton?

Yes, exactly. It could be in the space where the battery used to be also, attached to the engine of course:P

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1 hour ago, Barney Eaton said:

Or like the later 3800 Supercharged V6 ..........save your grey matter and use what GM engineered.

I toured the Hennessy performance shop down in Kyle TX last fall and they were taking that high performance Dodge and modifying it.........mostly with software, they changed the blower pulley for more boost, new exhaust and the rest was

modifications to the ECM chip..........how much could you get out of the Reatta by modifying the timing, injectors and transmission shift points?

I haven't found much improvement with chips, fuel pumps or injectors. Those are usually supporting modifications for actual physical changes to the engine such as a camshaft changes, forced induction, running a different fuel etc... The engine just doesn't breath deeply enough, so forced induction works well. I agree if you want plug and play large power increases, the factory s/c option makes a lot of sense. One place where chips, injectors and fuel  pumps would be a necessity would be to run E85. If you can't get enough air in, use a fuel that carries some of its own oxygen, for a net tq. gain. Of course you use 30ish% more, and would be even more effective it the compression was bumped up at least two whole numbers, or more.

 

I don't know enough about the transaxle to comment much about the shift points. I know the TV cable has some effect on it but I think the governor in the trans. would need to be modified to change the shift point. This is for the mechanical trans. in 88-90. Probably wouldn't help a lot if the engine has fallen on its face 1500 rpm back :rolleyes:

Edited by 2seater (see edit history)

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2 hours ago, 2seater said:

I don't know enough about the transaxle to comment much about the shift points. I know the TV cable has some effect on it but I think the governor in the trans. would need to be modified to change the shift point. This is for the mechanical trans. in 88-90. Probably wouldn't help a lot if the engine has fallen on its face 1500 rpm back :rolleyes:

 

Yeah that is one drawback about this tranny, whereas I have heard of people making adjustments to the shiftpoints on other models to get better performance. Actually if you do not have the TV cable adjusted properly on our setup the OD doesn't function right if at all, I know from experience.<_<

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Putting a switch on your car to turn off the torque converter lockup makes the car feel like is has better performance. With the switch turned off the car accelerates better (in my opinion) because you don't have to wait for the converter to unlock when you mash on the gas pedal . It allows the RPM to jump up immediately allowing the engine to accelerate better. Otherwise you have to keep mashing down on the gas, (usually lugging the engine), until the converter unlocks. I personally think having the converter unlocked is easier on the transmission because it eliminates the abrupt transition between lock and unlock of the converter. When I drive on the interstate, which is seldom, I flip the switch to the on position to lower the RPM and to get better fuel mileage. This idea probably isn't for everyone but I thought I would throw it out there since were talking about performance.

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10 hours ago, 89RedDarkGrey said:

Here's some nifty info for us- 

 

 

Interesting but I noticed they didn't really specify that the next generation, the immediate predecessor to the 3800, was not used in the GN? The GN has the traditional flat tappet lifters, rocker shafts and an oil pump driven from a camshaft drive. It didn't have a distributor but used an external cam position sensor in the same location as the distributor which drives the oil pump in the old traditional way. Not a big deal I guess, just unclear.

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While I'm on the subject of things that makes it feel like you are getting better performance, I wonder if my cold air intake actually makes any more power. It does give the sensation of having more power because it gives the engine a little more (louder) sound when you open up the throttle pretty wide. The stock air cleaner is almost silent. The cold air intake combined with the unlocked torque converter really gives a seat of the pants feeling that you are accelerating better. I really doubt I've done much to improve performance but it makes my car more fun to drive. :)

 

Air Cleaner (14).JPG

 

Air Cleaner (15).JPG

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29 minutes ago, Ronnie said:

Putting a switch on your car to turn off the torque converter lockup makes the car feel like is has better performance. With the switch turned off the car accelerates better (in my opinion) because you don't have to wait for the converter to unlock when you mash on the gas pedal . It allows the RPM to jump up immediately allowing the engine to accelerate better. Otherwise you have to keep mashing down on the gas, (usually lugging the engine), until the converter unlocks. I personally think having the converter unlocked is easier on the transmission because it eliminates the abrupt transition between lock and unlock of the converter. When I drive on the interstate, which is seldom, I flip the switch to the on position to lower the RPM and to get better fuel mileage. This idea probably isn't for everyone but I thought I would throw it out there since were talking about performance.

I agree, it does let the engine operate more responsively probably at a small cost in mileage. I did something along those lines when I started trying my own chip burning. I raised the minimum lockup speed to something like 55mph. Not a perfect solution but for urban/suburban driving it does feel a bit peppier.

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2 minutes ago, Ronnie said:

cold air intake

 

As usual- all those do is sound cool. Without a cover- to properly duct in actual outside ("cold") air- those setups generally suck in hot (warmer than outside engine compartment) air, slightly skewing any reading put out by the Air Charge Sensor (assuming most users even hook them up) and ultimately changing the air/fuel map. It's ok if you're retuning anyway, or have a completely Aftermarket ECM-ECU-PCM or a variance of those, in a more "modern" setup.

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Does anyone have thoughts to share on the supercharged conversion? Even better if you had the car with both engines. I am truly curious on the results and experience. 63Viking mentioned possibly adding a turbocharger as well, which would really be new ground, and got me to thinking about doing a s/c engine myself. I dropped off the rusty block I received from Daves89 at the machine shop to have it checked out for possible use. If it can be saved I am warming up to the idea of adding a supercharger to see what that experience is like.

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7 minutes ago, 89RedDarkGrey said:

 

As usual- all those do is sound cool. Without a cover- to properly duct in actual outside ("cold") air- those setups generally suck in hot (warmer than outside engine compartment) air, slightly skewing any reading put out by the Air Charge Sensor (assuming most users even hook them up) and ultimately changing the air/fuel map. It's ok if you're retuning anyway, or have a completely Aftermarket ECM-ECU-PCM or a variance of those, in a more "modern" setup.

Yes, there is a chart the ECM reads to adjust timing based on inlet air temperature. LV8 is an engine load calculation based on several inputs, with 256 being maximum load.  It has pretty large cells so its not really linear but this is what it looks like:

 

MAT chart.jpg

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2 minutes ago, 2seater said:

Yes, there is a chart the ECM reads to adjust timing based on inlet air temperature. LV8 is an engine load calculation based on several inputs, with 256 being maximum load.

 

I'm a little confused. Are you saying I may have hurt performance with the chrome plumbing I added? :)

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15 minutes ago, 2seater said:

Does anyone have thoughts to share on the supercharged conversion?

 

I have actually thought about doing just a supercharger bolted on my engine and changing the pulley size to give a very mild boost that would be easy on the transmission. I never got really serious about it but I did check into it a little a few years ago. If I remember correctly it might be possible to do without swapping the whole engine.

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4 minutes ago, Ronnie said:

 

I'm a little confused. Are you saying I may have hurt performance with the chrome plumbing I added? :)

Sorry, that wasn't my intention, I was just adding detail to the previous post. I believe you relocated your temperature sensor to the new inlet pipe, so the ECM should be getting correct information. Easy to see what the incoming air temperature is in diagnostics so you can judge if it may be an issue. The other thing that many cone filters do for you is give a larger filter area than the stock panel filter.

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4 minutes ago, 2seater said:

Easy to see what the incoming air temperature is in diagnostics so you can judge if it may be an issue.

Should I be comparing that reading to outside ambient air temperature to know? I wish I had done some testing like that before installing the cone filter. Actually the extra intake noise was what I was going for. I didn't really expect any performance gain.

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9 minutes ago, Ronnie said:

 

I have actually thought about doing just a supercharger bolted on my engine and changing the pulley size to give a very mild boost that would be easy on the transmission. I never got really serious about it but I did check into it a little a few years ago. If I remember correctly it might be possible to do without swapping the whole engine.

That would be my intention as well. Remember F14Crazy? He had a long thread about doing exactly that. There are subtle differences internally on the s/c engines, which I think became more robust as different variations increased in power. The early 90's engines are little different with possible things like full floating piston pins which would show up as different part numbers but otherwise similar. Same heads, block, cam as the n/a version.

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My '71 Nova had a "Thermostatic" air cleaner on it's 250 cid  1 bbl Rochester. Just below the snorkel, was a duct attached to a sheet metal shroud around the exhaust manifold called the Heat Stove. A bimetal sensor in the air cleaner- controlled whether vacuum was operating a diaphragm servo- that controlled a damper door to the Stove. The valve got stuck once- and the heated air made the hot engine ping. Warm air in a cold, carbureted engine will make it run smoother.

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10 minutes ago, Ronnie said:

Should I be comparing that reading to outside ambient air temperature to know? I wish I had done some testing like that before installing the cone filter. Actually the extra intake noise was what I was going for. I didn't really expect any performance gain.

Sure. The closer it is to the outside air temp. the better. I usually see several degrees warmer when in traffic or very low speed just from the general warming of the immediate area around the car but cools once moving. From the chart, there is little chance it is pulling timing until you get over 33*C or 91*F

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3 minutes ago, 2seater said:

Sure. The closer it is to the outside air temp. the better. I usually see several degrees warmer when in traffic or very low speed just from the general warming of the immediate area around the car but cools once moving. From the chart, there is little chance it is pulling timing until you get over 33*C or 91*F

I'll try to remember to check it out when warm weather rolls around.

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22 minutes ago, 2seater said:

The other thing that many cone filters do for you is give a larger filter area than the stock panel filter.

 

And anyone who reads this- please- don't ever use one of those filters you spray "wax" or some "coating" on. It gets on the MAF and cooks to it, and could easily ruin the MAF. 

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4 minutes ago, 89RedDarkGrey said:

I'd be weary of big power on a 2 bolt main setup.

Yes, discretion is needed. I think the trans. will scatter long before the engine will as long as it is tuned well and doesn't knock itself to death. From much information I have found over the years, is our 3800 is capable of about 500 flywheel hp before you drive over the crank. If I could get somewhere close to half of that, I figure it would be just right.

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5 minutes ago, 2seater said:

From the chart, there is little chance it is pulling timing until you get over 33*C or 91*F

 

Southern States area. +90F & 85% humidity. AC on. Traffic. Underhood temps can easily exceed 150F.

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