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How To get Less Drag on L98

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Old 03-11-2008, 07:31 PM
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Car: 1987 GTA Vert & 1991 GTA 5 Speed
Engine: 87 GTA-L98 91 GTA LB9
Transmission: GTA-700R4 & GTA T5
How To get Less Drag on L98

Just got a 87 GTA w/ a blown up 305TPI. I also got in the deal a 350TPI from a 88 Formula that I will switch the blown out engine with. While the engine is out I want to allow it to breath a little easier and run w/ less load. So I want to put on an overdrive pulley, electric water pump, and I am looking at buying a set of used headers.

What all has to be done when adding these 2 items on the front of an L98?
Old 03-11-2008, 07:48 PM
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Re: How To get Less Drag on L98

Make sure the alternator is up to the task, it will work pretty hard running an electric water pump on a street car. Take it to your local starter/alternator rebuilder and have it tested, make sure its good.

Not sure what you mean by 'overdrive pulley'... its awfully vauge. Headers is a good idea, the exhaust is a big problem on the V8 cars. A decent set of headers (1-5/8" minimum) will help power, sound, and fuel economy as well. No negatives to a set of headers IF YOU GET A QUALITY SET. Cheap ones are exactly that - cheap. They probably won't fit well, and will likely leak too. Spend money on a good set (new or used).
Old 03-11-2008, 08:46 PM
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Car: 1987 GTA Vert & 1991 GTA 5 Speed
Engine: 87 GTA-L98 91 GTA LB9
Transmission: GTA-700R4 & GTA T5
Re: How To get Less Drag on L98

This is a quote from a retailer regarding the overdrive pulley, "THIS PULLEY REDUCES THE CRANKSHAFTS TURNING MASS, THEREBY ALLOWING YOUR ENGINE TO TURN HIGHER RPM’S FASTER. DON’T BE FOOLED, NO PULLEY INCREASES AN ENGINES HORSEPOWER, IT ONLY REDUCES THE AMOUNT OF MASS YOUR ENGINE HAS TO TURN THEREBY FREEING UP 10-15% OF YOUR EXISTING POWER. " It was also a reccomended MOD on the Corvette Fever (about 80% sure I saw it on that site). Its ironic that Vette Fever said it added about 5-7 hp with the reduction of engine load! Here is an ebay link to one http://cgi.ebay.com/ebaymotors/ws/eB...MEWA:IT&ih=011
Old 03-11-2008, 08:52 PM
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Re: How To get Less Drag on L98

Might also want to think of things like a crank scraper. If you can, chuck your AIR pump. Sure, it's not hard to turn, but whatever, it has to count for something.
Old 03-11-2008, 09:31 PM
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Car: 1987 GTA Vert & 1991 GTA 5 Speed
Engine: 87 GTA-L98 91 GTA LB9
Transmission: GTA-700R4 & GTA T5
Re: How To get Less Drag on L98

No problem, but what is a crank spacer? Tell me how to install it (is it hard to diy?) What is involved in removing the smog. Will this give me emission inspection problems, I live in NC.
Old 03-11-2008, 10:19 PM
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Re: How To get Less Drag on L98

Scraper. It helps with oil control. Generally a 0-2HP mod. I wouldn't lose sleep over it.

IMHO (very humble) pulleys are for r|cers. There, I said it. :gasp:. Reason being, import engines are already running at 99% capacity, so you need to wring every last HP out of it you can. So you kill off your powersteering/alternator/waterpump capacity for a little more HP. It has nothing to do with reducing mass, it turns those things slower. That means it uses less HP to turn them. Ok, but when you turn it less, you get less output - ie it's harder to use your power steering, you don't get as much cooling from the waterpump, you don't get as much power from the alternator.
(This is an aside, since you mentioned an electric waterpump).

Anyway, the gist of my rant there is that our engines, even the good ones like our TPI 305, are nowhere close to top efficiency. You can gain HP without the losses associated with underdrive pulleys. As Adam mentioned, exhaust is one of those win-win things. Go for the win-wins first. ie. you don't lose mileage, reliability, etc etc when upgrading the exhaust. You gain sound (most of us consider that a win...).

There are other win win upgrades, but a top notch exhaust should expel your budget for now ($800 or so, all said and done).
Old 03-11-2008, 11:19 PM
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Re: How To get Less Drag on L98

Losing the AIR system fails your emissions tests wherever they have a visual.

If you drop the oilpan, a scraper isn't a hard thing to install. That's IF you have the oilpan already pulled.

I agree with the underdrive on these cars. Kind of iffy, really. Going with an electric water pump will require a lot more power from your alt. You won't want to underdrive something that likely wouldn't be putting out the power needed when driven at factory ratios.
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