machen

I have a 93 Z28. Chevorlet Cold Air Induction. Doug's Shorty Headers. Hypertech Chip installed with the 175 Thermostat. Is it worth ~350 bucks to install a BBK 52mm Throttle body? If so, what kind of gain can I expect. I want to do it because it will help a bit. Iknow 58mm is too big unless other mods are done. I have owned this car for 17 years. It has 19,000 miles on it and in prestine condition, garage kept. Color is Grey, Green metallic. Added the rear spoiler painted black and painted the hood inserts black. Love the car. Thanks in advance. Before anyone responds, I am not sure where this is going. I leave the car parked in the garage since I work in Korea. I want more and more, but have to keep the car capable of passing emsission since I live in Virginia. Thanks in advance. Merle

RamAir95TA

At your power level, no. Usually a bigger throttle body is the LAST item on the bolt-on list that people add simply because the stock one works very well. Have you considered upgrading your suspension also?

I would invest in ditching that Hypertech crap for a mail-order tune, ditch the 175-degree thermostat (Where'd you get that anyway? Stock is 180, the most popular aftermarket is 160) and replace it with a 160 to maximize your cooling system in conjunction with the tune, then add a cat-back exhaust to go with those headers.

Car sounds real nice. 19k miles? And a 93? Sweet!

koolaid_kid

Once you do the work RamAir95TA suggests you can bolt on the BBK. You must open up the air flow front to back before a larger throttle body is useful at all. however, don't expect a 50 hp increase, it just ain't gonna happen. Most believe the money is better spent in other areas, but if you can find a deal on a good used one it is not a bad thing to have to take advantage of future upgrades. I had my stock one bored out and I preferred it to an aftermarket one, since it was perfect from the factory as a 48mm.
Suspension work is an excellent suggestion as it puts the power you have down properly, and will prepare you for future power upgrades.
AFA the tune, you have a chip which must be replaced, not sure on the procedure. The Hypertech is O.K. for certain things, such as changing the rear end, tires, etc., but the tune is completely useless. I had one, tested it at the track, and there was literally no difference between its tune and the stock one.
I am also curious at that thermostat. The 160 is the accepted standard, but the tune must turn the fans on at different temps for the thermostat to be effective.

bw_hunter

Even after adding what Joe suggests you won't need or benefit from a larger TB. The stock TB flows enough to support 450 hp at the crank....

machen

Thanks guys, that is what I thought. I probably mis spoke on the thermostat, it is a 160 and required with the Hypertech chip. Now you all have told me it is crap, I will mail order one. The 93's you have to replace the chip.

I already have the Eibach pro kit springs. I was going just replace the springs since there is low miles on the car. Since I found out the fronts are hard to do, I am going to replace all of the shocks during the install.

Thanks again

n2ceptor

I disagree with said posting on Hypertech... On my 93Z, stock, I ran the Hypertech Thermomaster with no issues and had better throttle response, lower temp, ect...

I would not recommend for modified engines....

bw_hunter

Are those seat of the pants impressions or did you dyno it?

boostedz28lt1

Hypercrap..... stick with your stock TB untill later on. buy some LCA

96capricemgr

It was touched on before, for 52mm you are better off to go rebored stocker and avaoid the IAC and TPS hassles of the aftermarket TBs. Any power gain would be minimal and I would sooner do rockers and springs.

bkpliskin

What IAC and TPS hassles are you refering to? I swapped my stocker for a 52mm unit and it took me about a half hour start to finish. There were no issues whatsoever with the IAC or TPS. Summit brand TB.

andysc

I had a stock one opened up to 52mm. I have most bolt ons.
The biggest gain was in throttle response. The butt o meter felt the gain, but was not faster time wise. I would not spend $200.00 for one, I got mine off ebay for I think it was $130.00, and I had three old throttle bodies laying around, and the guy gave me $25.00 for each I believe. So it really cost me about 60 dollars.

hth

andy schuck