Throttle body spacer

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Throttle body spacer

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Blazer >> Modifications >> Performance & Brainstorming >> Engine & Internal >> Throttle body spacer

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Throttle body spacer - 5/11/2005 10:49:25 AM

shawn_dh

Posts: 14
Joined: 3/7/2005
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I have a 98 4.3L blazer. Besides a little improvement in HP and torq. what type of improvement in gas mileage will a throttle body spacer give, if any. If anybody has one, do you think that it would be worth purchasing just for the benefits of gas economy, or would it be a waste of money? Thanks.

Post #: 1

RE: Throttle body spacer - 5/12/2005 4:49:12 PM

timetoblaze

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as far as gas economy goes i wouldnt.. i think you might gain like 1-2 mpg and i really dont think that they give you all that much horsepower at least i dont think its that worth buying for that kinda money thats just me though

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RE: Throttle body spacer - 5/12/2005 9:27:25 PM

zero psi

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i put one on my old 88 k5 and didn't notice a thing. not worth the money or effort in my opinion.

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RE: Throttle body spacer - 5/13/2005 2:10:16 AM

shawn_dh

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Joined: 3/7/2005
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Thank you for the input. They sound good in theory, but I am still skeptical of the product. Thanks again.

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Post #: 4

RE: Throttle body spacer - 5/18/2005 9:27:45 PM

timetoblaze

Posts: 586
Joined: 9/9/2004
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shawn, have you done any mods to your truck yet?

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Because going fast looks much cooler when your car is on fire...

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Post #: 5

RE: Throttle body spacer - 5/18/2005 9:57:47 PM

02 Vortech

Posts: 279
Joined: 12/11/2004
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yeah get one you can definatly feel the difference

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Post #: 6

RE: Throttle body spacer - 5/18/2005 10:30:07 PM

shawn_dh

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No I have not done any mods.

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RE: Throttle body spacer - 6/10/2005 1:36:33 PM

02 Vortech

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You can feel the difference and i forgot to mention that my exhaust has a burble to it now after you rev it up but as far as gas mileage i havent seen a difference but i did notice rpm's rise faster and acceleration increase

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Post #: 8

RE: Throttle body spacer - 6/10/2005 2:35:48 PM

chevylane2003

Posts: 161
Joined: 6/1/2005
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Okay it all depends on which one you get.

If it has straight through holes then don't expect much. You may see a little change but not enough to make you feel it was worth it.

Now if you get one of those with the spiraled out holes then the diff would be quite noticeable. How well depends on the angle and what-not of the spirals.

The story as I can see it is this. If it is just a straight hole then it is doing nothing to the airflow. No disturbance, no cooling, no de-atomizing, no nothing. All it is doing is giving the fuel about an 1/8th of a second more to try to mix with the air. It is acting as the name states. Spacing things out.

If the hole is not smooth; may it be spiraled or grooved it is accually effecting the air-flow. These are set up to creat a votex of sort. This will spin the air as it comes in therefor doing a small touch of cooling. Also the spiraling effect will help to mix the fuel with the air. Better mixxing leads to better burning. If it burnes stronger you get more bang for the buck leading to better mileage when your foot is not in the floorboard.

Picture it like this. While making some kool-aid put the water and the mix in a pitchure and just poor it into another one. Don't stir it. With this you will not yet have kool-aid just some nasty watery stuff. Now start over. Put your water and mix in the pitchure and give a good stir. Get it all spining pretty well. As it spins poor it into another pitchure. You will notice a feel of added force coming off of it. Once it is in the other pitchure you will have something much closer to a good kool-aid.

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Post #: 9

RE: Throttle body spacer - 6/11/2005 10:14:19 AM

zero psi

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From: maynard, MA
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now im thirsty.

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Post #: 10

RE: Throttle body spacer - 6/11/2005 11:34:03 PM

chevylane2003

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ha ha ha ha

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Post #: 11

RE: Throttle body spacer - 6/13/2005 1:20:01 PM

swartlkk

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Joined: 5/1/2005
From: Waterloo, NY
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The mixing aspect of a TB spacer really isn't where the increase in power (torque) is from. Basically, the way a spacer works (regardless whether it is under a carb, TBI, or on a MPI manifold) is by increasing the volume of air between the throttle and the cylinders. What this increase in volume does is shifts the torque curve down lower in the rpm range. Think of it this way. What is the difference between run-of-the-mill dual plane intakes and single plane intakes in terms of their respective power-band? The dual plane intakes have power bands much lower in the rpm range than the single planes because of the added volume of air. By adding a spacer, you are increasing this volume of air and shifting the torque curve down. So say you have 285 ftlbs of peak torque at 3500rpm. With a 1" spacer, you may now have 285ftlbs peak torque, but it may now be down at 2700rpm. By shifting the peak torque lower, you boosted the torque (mind you that the actual torque curve changes very little with a spacer - the entire curve shifts) from off idle to the new peak rpm, but after the new peak rpm, the torque has fallen off.

Here's an illustration:

Now, here's where the mileage increase comes in. If you very rarely get up in the rpm range (past peak torque), then by shifting the curve lower in the rpm range you are decreasing the throttle required to reach the same speed as without the spacer.

Back to the discussion on the 'spiral bore' of many of the aftermarket available spacers. This spiral does NOTHING. Every little bit that it protrudes into the air stream slows down the main stream velocity, thus hindering performance. Many of these designs don't impinge on the air stream at all and if they don't get out into the air stream, then how can they influence the airflow much?

I produced a limited run of throttle body spacers for the Dodge Intrepid 3.3L & 3.5L engines for DodgeIntrepid.net members and EVERY single person that purchased a kit from me noticed atleast 2mpg better fuel mileage. One member even dyno'd his 3.5L with my spacers (smooth bore), PowerAids spacers (spiral bore), and bone stock. His dyno showed a 500rpm decrease in peak torque rpm level with both of the spacers (only difference between the two spacers was the bore design). Nothing else changed. Peak horsepower was the same and at the same rpm and peak torque remained the same.

Take everything that you have read with a grain of salt, but I speak from actual first hand experience. I know for a fact that on my Chevelle, my 1" 4-hole spacer makes a huge difference with it in than with it out on top of my Edelbrock Torquer 2 single plane manifold. But I never did dyno it to figure out exactly what the difference was. The car pulls much better in the lower rpm with it and it was free so I decided to leave it on.

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2004 Rainier
1970 Chevelle - Resto
1974 K5 Blazer - Resto

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Post #: 12

RE: Throttle body spacer - 6/13/2005 2:16:31 PM

shawn_dh

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Joined: 3/7/2005
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Thanks for the info. Very well explained. I do tow a small boat, 3500lbs, every weekend. It would be interesting to see what improvements can be felt. Thanks.

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Post #: 13