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I think what he meant is that more air coming in is different than air flowing out easier.Quote:
Originally Posted by dsmuts
When I had my stock airbox, I removed my MAF screen and my idle wasn't too happy.
Also, what if you cut the MAF screen so that it only provides the laminar flow over the sensor? Leaving the rest of the TB unrestricted?
When you add headers the inlet flow goes up. According to people in this thread that means your tune will be out of whack. It's the MAF sensor's job to see that extra air and add fuel accordingly, not get thrown through a loop with a simple change.Quote:
Originally Posted by nos4blood70
Adding headers does not affect the maf calibration.
intake and throttle body do.
Quote:
Originally Posted by fry626
Rob, This poster is incorrect in their assumptions. Like others mentioned, if you increase the size of the TB and keep the maf the same, then there is more air going into the engine (or available to the engine) which changes the maf reading and w/o a tune this is a bad thing that may run you lean and blow your motor.
If you need sensors, I'd suggest either finding a decent local JY or calling your local 3800 guru to see what parts he has laying around.
I'm not assuming anything. These are the facts. 3mm change in the throttle body diameter isn't going to effect the tune in any way.
By your logic, people need a retune any time there's more than a 1% change in air density.
If you have back to back dyno plots or AFR graphs to prove otherwise I'd love to see them.
If only you knew how we modify our throttle bodies.
If you haven changed from your current TB to a bigger one and scanned personally,then you ARE just assuming... because the maf reads off air and DIAMETER of that intake air... how can you say 3mm isn that big of a difference in the readings of a maf that is so sensitive...???Quote:
Originally Posted by fry626
point being were not just saying this to say it, weve all (for the most part) done this personally and just know. Its a pretty easy concept to grasp really...
Ok end all to this arguement. This is what you are referring to, no? VVV
ZZPerformance - L67 High Velocity Throttle Body #MT-HVTBL67
Lets see what ZZP has to say about it...
Notice the part I underlined...Quote:
Introducing the ZZPerformance High Velocity Throttle Body. A total work of art designed to work perfectly in the 97-03 Grand Prix GTP, 97+ Regal GS, 04-05 Monte Carlo/Impala SS & 97+ Bonneville SSEi. This was ZZPerformance’s first product!Stage one work is optimized for getting a Series II 3800 car down to the high 12 second track times. Once you are working on mid/low 12's or lower the stage 2 is the better choice.
The next step up would be our Northstar throttle body kit.
Stage 1 Features include:
- Porting the TB from 69 to 72mm on the outlet
- Installing a new larger 72mm TB plate
- Machining the rod that holds the plate into a trapezoid shape
- Using low profile rounded head screws to retain the plate
- Black anodized linkage
- 72mm gasket included
- Security screws replaced with stainless socket head bolts
- Comes with TPS and IAC sensors (comes without the MAF sensor)
- Works great with our throttlebody spacer
Stage 2 includes all of above plus:
- Inlet epoxy work
- Removal of hump above the MAF sensor
- MAF chart modification recommended for AFR calibration and streamlining
*To receive full core credit you must return a complete throttle body with IAC and TPS sensors. It can be from any 97+ 3800. Excessively Dirty or abused cores may be subject to a reduction in core money. Please package well because it is common for the sensors to arrive damaged from poor packaging.
For more information about our High Velocity Throttle Body Click here
Throttle body: 84-89 in/lbs
"MAF chart modification recommended for AFR calibration and streamlining" means you need to tune the pcm
It should have a * instead of a Bulletin as it is NOT included but it is necessary.
/thread
Thanks.
Because even removing the MAF screen causes a crappy MAF reading.
Ask icemann. He thought he was removing a restriction, now the car idles like poo.
Same with the '98 GT I had. I put it back in...my '03 didn't really react to it, so I didn't care...granted it was also TUNED for it. The MAF side of these cars are pretty finnicky...so, don't tune for it...let the car idle like crap...like all of the HVTBs from ZZP tend to do. Seen that day in and day out. Is there even a NEED for a modded TB? Maybe once you start upgrading the valvetrain then maybe.
Until then, save your damn money.