| HT4100 4.1, 4.5, 4.9 This forum is to discuss the newer aluminum block Cadillac engines. | Cadillac Forums: DeVille 4.9 Throttle body spacer 
05-02-09, 01:26 PM
| | Cadillac Owners Member Cadillac(s): none  | | Join Date: Apr 2009 Location: Qc, Canada Age: 49 | |  DeVille 4.9 Throttle body spacer
I read somewhere that a Throttle Body Spacer might help a little bit on performance, and because I need to raise the TB a little bit, I am on the market to find a spacer.
I am doing a swap out of a 93 DeVille to a 88 Fiero.
I can not find any spacer specificaly made for the 4.9 TB, so I am wondering which other GM throttle body base plate I can compare with. On picture, TBI for 305/350 SBC looks alike. May I used a TB spacer for those on my 4.9? |
05-02-09, 06:40 PM
| | Cadillac Owners Connoisseur Cadillac(s): 1988 Allante' (sold), 1984 Eldorado 4100 91 Allante | | Join Date: Feb 2003 Location: california Age: 62 | | | Re: DeVille 4.9 Throttle body spacer
The small block Chevy should work, same bolt spacing. But I dont think it will help. These spacers were used on the old 2 injectors in the throttle body systems used on 4.5 Cads, 4.1 Cads and Chevy trucks. Spacing the 2 injectors higher supposedly atomized the fuel better?? The 4.9 is port injected correct? 8 injectors, not 2. |
05-02-09, 09:37 PM
| | Cadillac Owners Member Cadillac(s): none | | Join Date: Apr 2009 Location: Qc, Canada Age: 49 | | | Re: DeVille 4.9 Throttle body spacer
You are probably right but, as on my Dodge Dakota,the throttle body spacer certainly fool the mass air flow. Anyways I need something to raise the air hat so why not at TB spacer? |
05-02-09, 11:40 PM
| | Cadillac Owners Connoisseur Cadillac(s): 1988 Allante' (sold), 1984 Eldorado 4100 91 Allante | | Join Date: Feb 2003 Location: california Age: 62 | | | Re: DeVille 4.9 Throttle body spacer
Keep in mind this is a speed density injector system, not a mass air flow system. It already knows the designed air into the engine. So besides raising everything, it will not give more power nor torque. |
05-03-09, 09:41 AM
| | Cadillac Owners Fanatic Cadillac(s): 1993 Eldo 4.9 66K miles | | Join Date: Nov 2005 Location: Nazi Jerky, libtard central | | | Re: DeVille 4.9 Throttle body spacer
Quote:
Originally Posted by carnut 
The 4.9 is port injected correct? 8 injectors, not 2.
| Correct. It will raise the TB and that's about it. If anything, it will restrict air flow a bit. |
05-03-09, 10:42 PM
| | Cadillac Owners Fanatic Cadillac(s): '85 FWD fleetwood, '93 fleetwood Bro | | Join Date: Mar 2009 Location: mich Age: 78 | | | Re: DeVille 4.9 Throttle body spacer
If the spacer has the correct bore diameter it shouldn't restrict flow. There are some that have swirl designs in the bores to atomize fuel better. Summit Racing has them. It's called swirl-torque. Made for GM engines/wTBI If your gonna buy a spacer anyway, might as well try one that could help a bit.
And if you do, report back here and tell us if it improved anything. People tend to be nay-sayers even if they haven't tried the parts in question.
Cadillacs can use all the help they can get with these engines. |
05-04-09, 06:58 PM
|  | Cadillac Owners Enthusiast Cadillac(s): '87 Coupe DeVille 4.1L FWD(New engine Dec '08) | | Join Date: May 2008 Location: Austin(area), Tx | | | Re: DeVille 4.9 Throttle body spacer
I agree with steelybill. Check it out and let us know how it does. I've also considered a spacer, but hadn't found one correct for my application. |
05-17-09, 12:15 PM
| | Cadillac Owners Member Cadillac(s): none | | Join Date: Apr 2009 Location: Qc, Canada Age: 49 | | | Re: DeVille 4.9 Throttle body spacer
My 4.9 is for a project car, an 88 Pontiac Fiero, so I never drove the car with that engine in. I will then not be able to compare before and after.  | | Cadillac Discussion Tools | | | 
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