Improving the exsisting engine performance.

[9a pilot]

I am interested in how much room there is in factory setup for simple(and not so simple) tweakes using updated technology to increase the output and efficiency of what GM has already in place in terms of compatibility with the archaic engine managemanet.
Can the static compression be raised? If so, by how much?
Can a roller camshaft be retrofitted into flat tappet 3.8 block?
Can the stock computer be altered to accomodate? I know that chips have been available in the past.
Would a HEGO(heated) 02 be of any benifit?
I'm working with a 1984 3.8 Buick.
I have rebulit the carburator and the stock engine is good mechanically. The car no longer turns on the "check engine" light.
MPG is at or above the revised EPA numbers. It's at 24+ highway. Oil consumption is well within specs at 1 quart in 2000 miles. Driveability is as good as it can be... Ie it has a litlle converter bump and it idles like a buick 'even fire' V6..Which means its not as a good as a V8 in terms of smoothness, but its ok.

 

[RITTER]

headers
exhaust
head work ... port/polish, maybe even upgrade to a Stage1 head :idea:
rear gear ... major difference, if not already done
torque converter

In my opinion, if you are upgrading the 3.8L ... I would switch to a HOLLEY 2 barrel carburetor instead of trying to make the old CCC work properly with the upgrades. Or you could also go with a Quadrajet non-CCC setup :idea: I am not sure about the roller cam idea

 

[avin85cutty]

great thread idea. i have a 350 chevy in mine and was thinking about the same thing. any way to improve performance with upgrades. looking foward to see what people post about

 

[Peter]

A lot of people have talked about installing a 4.1 buick 4 barrel intake and a 4 barrel quadrajet along with headers in hopes of being around 200 HP after that work. I cant tell you how realistic it is, i suppose it is plausible but I dont know how the computer would adapt to adding the 4 barrel carb using the stock CCC system. It certainly sounds like something worth looking into, personally unless I was building the engine ground up in hopes of big power, I wouldnt touch the cam or heads or look into using a roller setup. I dont think the gains would be worth the time, effort and money unless you can expect getting 300+ horsepower out of a NA 3.8 of this age which i haven't heard of anybody accomplishing.

If you want to push all your chips into a NA 3.8 to make big power, more power to you and I would love to see somebody tackle it. The buick 3.8 has great drive ability and with some serious head work, a bigger cam, and a good exhaust and rear gears; i wouldnt see any reason it couldnt be a fun setup that gets solid efficiency.

 

[9a pilot]

I'm not looking for a specific x output. I have actual 'fast' cars for that. I'm interested in working around the edges of what is already in place. The car is to remain smog compliant, at least visually. A roller cam reduces frictional loss. I would try to get a grind that would not radically alter idle and low speed driveability or force a stall change within the conveter. I would like to reduce the chamber cc to get as close to 9:1 (a full point), and try to clean up the runners to get a little extra CFM. The cam would probably need a slight overlap increase to permit keeping the timing the same and still burn 87.
As far as headers are concerned, I'm not aware of any for an N/A G body. As far as the carb is concerned, since I just had it rebuilt, I would be hard pressed to cast it aside. I would think that the CFM rating would be adequate as is given the operating range and engine size. The limitations to all of this will probably be the stock computer.

 

[Peter]

I'm not looking for a specific x output. I have actual 'fast' cars for that. I'm interested in working around the edges of what is already in place. The car is to remain smog compliant, at least visually. A roller cam reduces frictional loss. I would try to get a grind that would not radically alter idle and low speed driveability or force a stall change within the conveter. I would like to reduce the chamber cc to get as close to 9:1 (a full point), and try to clean up the runners to get a little extra CFM. The cam would probably need a slight overlap increase to permit keeping the timing the same and still burn 87.
As far as headers are concerned, I'm not aware of any for an N/A G body. As far as the carb is concerned, since I just had it rebuilt, I would be hard pressed to cast it aside. I would think that the CFM rating would be adequate as is given the operating range and engine size. The limitations to all of this will probably be the stock computer.

The cpu would def be the determining factor of all this. My suggestion would be (assuming you have stock 2.41 gears that these 3.8's usually came with) is to focus on your rear end instead. move up to a nice 3.23 or 3.43 and you should be much much happier.

 

[9a pilot]

You may be correct. Starting at the rear may produce the best results.
I experienced good results when I replaced the 2:41s in my Malibu with 3:42s. But one thing I would do if I go this route with the Grand Prix is replace the 200M with a 200 4R.
I retained the THM 350C when I did the gear swap and was rewarded with 14-16mpg highway with the hopped up 229. That engine had a Comp HE-260,1.6 rockers, Performer intake, and a Holley 390. The problem was it was a 229. The Buick is a better engine.
I appreciate your input.

 

[LS1GN]

I don't think using a quart of oil every 2000 miles is "in spec"

Put a cheap turbo on there, maybe that will compensate for the poor flowing heads and small valves.

 

[Peter]

I don't think using a quart of oil every 2000 miles is "in spec"

back then they legitimately did have oil usage specs. it sounds valid to me

 

[Clone TIE Pilot]

headers
exhaust
head work ... port/polish, maybe even upgrade to a Stage1 head :idea:
rear gear ... major difference, if not already done
torque converter

In my opinion, if you are upgrading the 3.8L ... I would switch to a HOLLEY 2 barrel carburetor instead of trying to make the old CCC work properly with the upgrades. Or you could also go with a Quadrajet non-CCC setup :idea: I am not sure about the roller cam idea

You can swap in a CCC Qjet and 4bbl manifold from a 4.1L Buick V6. ECM can't tell the difference between a Djet and a Qjet so it will run just fine. Nets about 10 more HP and a little more torque , don't expect an 80 HP improvement though. You could even swap in a whole Buick 4.1 V6 if you really want to. The 3.8's and 4.1's biggest problem is the lame 8.5 CR, they sell thinner headgaskets for the turbo versions that bump CR to 9, they would work for the N/A versions, should improve quench as well. Even then most Buick V6 heads are very poor flowing, even the stock heads for GNs but they have turbos to more than make up for it..