Real tech discussion on design, fabrication, testing, development of custom or adapted parts for Pontiac Fieros. Not questions about the power a CAI will give.
Aaron wrote:Exactly. On the W-body you need the arm because there isn't enough room, but on the Fiero you can mount it right there. I'm not sure what advantages in power and throttle repsonse this will have, but it will be easier and cheaper.
Throttle response is how much time elapses between a movement of the throttle and power output from the engine. This is a direct function of the distance between the throttle and the intake valve. Moving the throttle body closer to the valves will improve throttle response.
How exactly does it "mess up the tune"? What bad habits does the engine gain from doing things this way?
I can see it screwing up your AE so that when you snapped the throttle open you'd get a rich bog for a split second.
I wonder if there would be any negative effects from having the throttle body closer to the plenum? I don't think so, does the arm contribute to plenum volume at all?
As for the tune, the intake/TB weren't the only things messing it up (Headers..) But whatever it was, the ECU didn't like it. That's part of my reason for going to a sequential MAF based system, it should be more accurate and "learn" better.
The MAF system will still need tuning... part throttle reversion can be tricky stuff.
Of course the arm contributes to plenum volume. It holds air, doesn't it?
When you crack the throttle open, you've got to wait for the air to get from the throttle body to the valves. It doesn't move at inifinite speed. Getting rid of the arm reduces the wait.
Moving the TB around can screw up an existing ECM calibration's AE setup. Other than that there's no disadvantage, as race cars do it all the time.
The Dark Side of Will wrote:The MAF system will still need tuning... part throttle reversion can be tricky stuff.
Of course the arm contributes to plenum volume. It holds air, doesn't it?
When you crack the throttle open, you've got to wait for the air to get from the throttle body to the valves. It doesn't move at inifinite speed. Getting rid of the arm reduces the wait.
Moving the TB around can screw up an existing ECM calibration's AE setup. Other than that there's no disadvantage, as race cars do it all the time.
That arm adds a LOT to plenum volume; doesn't that also have an effect on the location of the powerband? That ought to throw off tuning..
Got my LS1 throttle body in today. It is a bit dirty, but everything looks to be in good working order. It smells like fire. Not just typical combustion, but like it was IN a fire...But there don't seem to be any abnormal markings. Backside is plenty dirty as expected, and as usual it doesn't open fully and the two plate screws are like 1/8" too long...Typical LS1...
On a side note, 96-97 UIM should be on it's way, as are 96-97 injectors, an ignition, and coils. New AC Delco plug wires came in the other day as well.
Found a 96-97 Fuel rail with injectors. I'm not sure if the wiring harness part or anything else is included, but that doesn't really matter. $50 shipped.
Aaron wrote:Found a 96-97 Fuel rail with injectors. I'm not sure if the wiring harness part or anything else is included, but that doesn't really matter. $50 shipped.
looks like the 96-97 rail is only one small step away from being a returnless fuel setup..
For now I'm just going to run it like stock, no need in further complicating this.
I also got a pair of 96-97 valve covers, front and rear, for $10 shipped from the same seller. I doubt I'll use the front one, but it can't hurt to have (These make valve covers 13 and 14 of mine...)
