Throttle body

[mr289]

I have a 99 z28 havent done much to it i have a flowmaster exhaust and a kn air kit. Wanted to know what kind of results i should expect upgrading the throttle body to the 80 mm. Is this worth it will really gain more pep

[BLK2KSS]

You will feel a bit more throttle response but nothing real serious in terms of hp. If you find a good deal on one id say go ahead and do it but you will see more from a set of long tubes that can be had for around the same price as a good tb.

[JayTA98]

You will feel a bit more throttle response but nothing real serious in terms of hp. If you find a good deal on one id say go ahead and do it but you will see more from a set of long tubes that can be had for around the same price as a good tb.

Agree with blk2kss. If you want you can port and polish your TB and you will get a slight increase in Throttle response. If you have a dremel tool buy the metal cutting tip(not the discs). I spend like $20 dollars in materials and about 2hrs of time. If you dont have a dremel tool then you can look in ebay for port and polish ls1 TB. Its about $60 plus core charge. When you receive your TB you send your stock one back and you get the core charge back.

Im thinking about getting headers but I don't want to be too loud. Is a DD car.

[2ManySS's]

Don't bother with a TB mod of any type until you have surpassed it 's flow rate abilities, which probably would be needing a pretty stout cam and head work before it happened.

The aftermarket suppliers and manufacturers don't bother telling you the whole story and dyno runs really don't also tell the story.
First with the dyno.
One it not exactly at the same everything, engine temp, ambient air quality etc one run will differ from the other, 2nd run is usually more. Plus now the fact from the first run the tires have settled onto the rollers and may have heated enough to grip a little different, this applies to chassis dyno's.
Secondly some changes the computer needs to relearn for so the initial change of a part may show a gain, but after the computer has a chance to adjust it actually could settle with a lower power number.

Now with these TB mods.
A larger opening "IS" going to flow more than a smaller one.
What you see "feel" with your foot is it takes less pedal to do the same thing as before.
It means nothing power wise, just takes less pedal effort to obtain the same result.
If a TB actually added power it would be at the top of the RPM game, not throttle tipin.
And again the stock TB bore size is easily 25%+ more than needed to begin with.

The aftermarket prays in this stuff.
I felt a difference so therefore it must work as advertised and they sell them like hot cakes.

Now the only thing I have not come across on these forums is the TPS mod.
Basically what that is, is making sure the TPS hits it voltage targets.
I don't know what idle volts or WOT volts are but these TPS's either can be adjusted or made to be adjusted so you can make sure the computer is giving it all. This mod is worth more than any of those free mods. Any manufacturer like GM does not test everything and these have found to be off before by me. I had a Monte that was showing 4.4 volts WOT and it was suppose to be 4.6, little dremel work on the TPS to make it adjustable and we got 4.65 while maintaining the idle max volts. That was a good seat of the pants different.

[KMdef9]

The 80mm would be far as I would go, otherwise any bigger your really starting to be limited by the intake inlet size. I think the aftermarket 80mm's look better, but to each their own on that. The P&P from eBay is a route alot of people have taken here, b/c the price is pretty good for the MOD.

As mentioned previously, it will help with response, not so much a huge HP gain. A larger mouthed TB will allow more air into the motor, but that doesn't always mean you'll be fully burning more. That lies more on your cam and headers.