LT1-LT4 Modifications 1993-97 Gen II Small Block V8

how to bore the throttle body to 52 mm?

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Old 04-22-2009, 11:31 AM
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Default how to bore the throttle body to 52 mm?

can anyone explain how to go about doing this?
Old 04-22-2009, 11:33 AM
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Originally Posted by shutzero
can anyone explain how to go about doing this?
You have to get the larger TB blades and open up the the bores "uniformly" to accommodate them. I believe there is more involved, but that's the idea.

A cam swap would be my next mod if I were you.
Old 04-22-2009, 11:38 AM
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If you are a machinist you should be able to figure it out, if not you should pay someone to do it.

The throttle blades are NOT round either, slightly oval so they seal a round hole when they are at a slight angle.
Old 04-22-2009, 01:11 PM
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you think i should go with a cam before i get heads/intake ported?
Old 04-22-2009, 01:13 PM
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Originally Posted by shutzero
you think i should go with a cam before i get heads/intake ported?
If you are planning on doing heads and cam, then you might as well tear into it all at once. I didn't have the money for heads, so I just did the cam swap. I also bought a PP 52mm TB because I got a really good deal on it.
Old 04-22-2009, 01:19 PM
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i do plan on doing heads and cam but i dont have the 1800 to get everything done by lloyd elliot yet, thats why im thinking about doing the little supporting mods until i get myself out of debt
Old 04-22-2009, 01:21 PM
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Originally Posted by shutzero
i do plan on doing heads and cam but i dont have the 1800 to get everything done by lloyd elliot yet, thats why im thinking about doing the little supporting mods until i get myself out of debt
Understood. Try to find someone selling a used Professional Products 52/58mm TB.
Old 04-22-2009, 01:22 PM
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Originally Posted by ss.slp.ls1
I also bought a PP 52mm TB because I got a really good deal on it.
I would never buy one of those because they are made in china. I would rather give my money to a company like Holley or someone american than waste a cent on someone who is not domestic.

Are you doing heads and cam or just bolt ons? If your doin H+C go 58mm, otherwise 52.
Old 04-22-2009, 01:22 PM
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48mm is plenty until u start getting into 500 hp range..just get a machine shop to port the tb and get the bigger blades.

id say save your money until you get enough for le2 heads. AI makes some good heads too and also has a cam package you should check them out too.
Old 04-22-2009, 01:24 PM
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Originally Posted by slomarao
I would never buy one of those because they are made in china. I would rather give my money to a company like Holley or someone american than waste a cent on someone who is not domestic.

Are you doing heads and cam or just bolt ons? If your doin H+C go 58mm, otherwise 52.
I bought it NIB from a member on here. Price couldn't be beat, even when new from their website. It works well too.
Old 04-22-2009, 01:25 PM
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im planning on going with the le2 setup ive been talking to lloyd about it for a while now...its just a matter of me getting the money. also, some guy on ebay is selling ported intake manifolds with increased runners and painted red or black for like 200 shipped not sure if anyone else has seen them or if theyre good or not
Old 04-22-2009, 01:28 PM
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Originally Posted by shutzero
im planning on going with the le2 setup ive been talking to lloyd about it for a while now...its just a matter of me getting the money. also, some guy on ebay is selling ported intake manifolds with increased runners and painted red or black for like 200 shipped not sure if anyone else has seen them or if theyre good or not
I wouldn't buy a ported intake from anyone other than straight from Lloyd or Ai. And I would never buy heads from anyone without a flowsheet (if not from Lloyd or Ai).
Old 04-22-2009, 01:29 PM
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Originally Posted by shutzero
im planning on going with the le2 setup ive been talking to lloyd about it for a while now...its just a matter of me getting the money. also, some guy on ebay is selling ported intake manifolds with increased runners and painted red or black for like 200 shipped not sure if anyone else has seen them or if theyre good or not
You will see little to no benefit from a ported intake manifold. The stock one flows plenty well for most heads/cam setups.
Old 04-22-2009, 01:34 PM
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i wanted to go with this cam from lloyd elliott
226/230 .565/.565 111 LSA
Old 04-22-2009, 01:35 PM
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Originally Posted by ramair95ta
you will see little to no benefit from a ported intake manifold. The stock one flows plenty well for most heads/cam setups.
+1...
Old 04-22-2009, 09:25 PM
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Old 04-22-2009, 09:44 PM
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I have seen a stock throttle body bored to 54mm and they used throttle body blades from a Cavalier/Sunfire.

The reason they didn't go any larger is that there isn't enough material on the factory throttle body, but I don't know if that part is true or not.
Old 04-22-2009, 10:27 PM
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Originally Posted by shutzero
i do plan on doing heads and cam but i dont have the 1800 to get everything done by lloyd elliot yet, thats why im thinking about doing the little supporting mods until i get myself out of debt
There's no real benefit to getting the TB done until you're making 420+hp. But that made me think, as I've never really read anyone say: Is that flywheel or rear wheel HP?

Anyways, a LE Budget build is $1100 and the LE1 is $1200, which if you have the boltons taken care of can make 400+rwhp through an M6. If you're wanting more than that, even the LE2 comes in @ $1650

I'd put my money into something else besides the TB right now.
Old 04-23-2009, 07:10 AM
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Porting the throttle body isn't difficult, but you will need the proper machining equipment, definitely would not use a dremel or any hand tool. I don’t like the throttle body to be bored past 52mm, the casting becomes very thin in places past that point. With the throttle body being cast aluminum, which is hard and brittle compared to a billet piece of 6061-T6, it does crack much easier. And most LT1 intake manifolds bores are 52mm already, a throttle body larger than 52mm will require porting the manifold. I have hear some stock intakes were 54mm but I don't think they are common.

Also like mentioned earlier throttle blades are not round, they are an elliptical shape. Also depending on what year of LT1 the angle, or ellipse shape, will be different. The 92-93 is different from the 94-97 throttle body. I would not put a stamped blade or one from another engine in the LT1 throttle body. The blade will control where the throttle shaft is positioned when closed, this can have an effect on your TPS voltage. All the blades I use are machined from .062 thick 6061-T6 aluminum on a fixture to give them the proper angle and shape.

The first throttle body I bored was for my car's head/cam swap about 7 years ago. After that I started to do them on the side and sell them on Ebay. So far I've done around 300 of them. If you look on my cardomain page in my sig I have some pics of my old machining setup.
Old 04-23-2009, 06:37 PM
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Ok cool so in my effots to save for the le2 what would be some good mods to get in the meantime? Would an msd coil help anything?


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