Cadillac Seville / Cadillac Eldorado Forum Discussion, 80mm throttle body question in Past Cadillac Vehicle Discussion; If I got to an 80mm TB, will it be too big for the intake? What's the intake's measurement? I've ...
- 05-15-03 11:41 AM #1
80mm throttle body question
If I got to an 80mm TB, will it be too big for the intake? What's the intake's measurement? I've only had the car a week, so I'm not up on any of it's specs. Thanks in advance.
- 05-15-03 12:46 PM #2
Increasing the TB diameter will have an adverse effect on overall performance unless several other modifications are also done to support it.
- 05-15-03 02:15 PM #3Cadillac Owners Connoisseur
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Your heads won't be able to move the volume that you'd be dumping in there. You'd need to rework the ports and find a better cam set ( Good luck if it's a Northstar! ) and a few other things to be able to see any benefit from that mod.
- 05-15-03 02:19 PM #4
Katshot, I was looking at quite a few things, that was just one thing. But I'm trying to avoid getting too deep into this. It's my daily driver, travel/trip car, so I'd say I'm willing to spend $1500 or so on mods. It's just so hard to find parts to start off, so I doubt I'll even be able to get carried away with the mods anyway.
I'll do a search on basic/initial mods and see what I can come up with.
- 05-15-03 02:31 PM #5
Usually, the best points to hit first are:
1. Air inlet (air filter and ducting)
2. Exhaust system (a good cat-back system usually covers this)
3. Maybe a PCM re-flash
The engine in "stock" form can USUALLY benefit from increasing air-flow capability at both ends, mainly because the OEM flash tends to be a little "fat" on the AFR (Air/Fuel Ratio). Remember, the engine's basically an air pump so the easier it can breath and exhaust air the better. You just have to also remember that in the "stock" vehicle, the air-flow is usually restricted only slightly by the inlet and exhaust, so improving inlet and exhaust too much can quickly make the ENGINE the restriction. It is also possible to cause driveability problems if the stock PCM flash isn't capable of "adjusting" for the modifications you make in the air-flow.
- 05-15-03 04:04 PM #6
I'd hope that GM's program can adjust for something as slight as an open air filter. My truck handles 4 extra lbs of boost safely with the stock program. It adjusts accordingly. I can't see a CAI mod leaning the AF ratio out in my Caddy. How conservative is our computer? I need to get into the scan port and check some stuff out. It'll help me learn the car some more.
Thanks for your help so far.
- 05-15-03 04:22 PM #7
No, a CAI won't generally cause any problem. But changing MAFs will. And so will changing TBs. Like I said, the stock flash tends to be a little on the fat side to help guard against detonation and keep NOX emmissions down.