Does anyone have an idea if a throttle body spacer would be a good idea on my 1998 gmc 2500 4x4 with a 454? Because a few years back we out one on my sisters 1998 chevy 1500 4x4 350 and it seemed to have better throttle response and it wasnt noisy at all. What are anyones thoughts on this because the trans dapt brand throttle body spacer is only 51 bucks (which is the same brand as the one i put on my sisters truck). And if you think the TBS is a bad idea for this application then what would be some good performance modifications for my truck that wont break my wallet?
Three words: "waste of money".
So what should i do to make my big block a raped ape??
The best way to start to modify for power is with a camshaft. Yes, it is major surgery, but this is the heart of the engine and on these motors it is the first thing I suggest doing. It is what I started with based on the recommendation of my shop, and this shop specializes in high performance modifications. At the same time I changed the heads to aluminum Edelbrock 110 cc chamber heads. Again, my shop said this was my best option for the end use of the truck. It depends on the year of manufacture of your block as to what you need in terms of cam profile, and heads, and what you are after.
I want torque out of my motor. I have a specialty high performance shop right here in my home town that selected the best cam profile for my fuel system (TBI) and the design of the pistons in the engine. My engine did not come with a roller cam, so we put in a roller cam, roller lifters and custom built steel roller rocker assemblies for the heads (the heads came with rocker assemblies but they did not work with the roller lifters we used). I am still using pump gas and can use regular. It does run better on the middle grade fuel however.
Then you have to get the system custom tuned by an expert. Again, my shop had all the technology and the technicians to tune my OEM ECU to the new set up, using a dynomometer and a lap top. We had to slightly modify the fuel pump to put out higher fuel pressure.
I already had Edelbrock stainless steel headers and put a ceramic coating on them to hold the heat in better and for looks. But headers by themselves, at least on this motor in this truck, don't do a whole lot for increasing performance. I have a new catalytic converter and a 4 inch pipe running from there back to the 4 inch muffler and out the end.
Next for me is going to be a super charger. Hopefully I will post pictures in a thread on this when it gets started. The same shop will be installing it.
So whats a ballpark estimate on how much you spent on rebuilding your big block?
We did not rebuild the block. We left it intact because the mileage on the engine was only 83,000. They felt I could get what I wanted without touching the block other than the camshaft. We did do a lot of little things besides the roller cam and roller valve components and aluminum heads.
I can also give you the cam specs. This camshaft was selected based on my engine. Yours may require something different based on the year of the engine and what you want to accomplish. We set a game plan before starting. We mutually decided that if we left the engine unmolested, they could squeeze maximum torque from it with what they did, using the stock TBI with some modifications, and I could still use regular pump gas.
If you wanted a super gonzo motor, you'd need to change pistons and maybe mill the deck or the heads to increase the compression ratio. We left my compression ratio relatively unchanged other than how it was affected by the new aluminum heads with a different chamber design and volume. If you start changing the deck height, etc., that means you can't run it on anything but premium, and I use my truck to tow a trailer for vacation, so that is not the best solution for me.
The total bill for everything, parts and labor including 3.90 hours of labor on the dyno @ $150/hr to tune it, was $5,751.58. You would need to read the information to understand why it was that much. If you pm me with your email I can scan and email you the complete invoice with all the information on what they did, line by line and all the parts. Very detailed invoice. I am very happy with the results, the truck has a lot more torque at the rear wheels. Once I put on the supercharger, I will have all the towing power I could want.
It won't do anything for you except take your money.