Ok so i was on ebay and came across this, what do you all think about it, and is it worth the money, and how much more power could i expect from it

http://cgi.ebay.com/ebaymotors/46mm-...QQcmdZViewItem

 

I like this one better:

http://cgi.ebay.com/ebaymotors/454-3...QQcmdZViewItem

It's just like yours except that it has 50mm throttle bores. I will be running one on my next TBI engine that is coming out of my truck. I think our stock TBI units are very restrictive on the air side so these pieces are good.

You can use a 454 TBI unit but you can't just bolt it down to a 350 intake because some of the air bleed passages are in a different spot. If you run it with an adapter on a 4bbl intake its fine.

 

would i be able to use the 454 one on my 305, my 305 is 100% stock?

 

I don't think it would be worth it since you valve train does not make much power over 5700 anyways. Our motors are mean't for lower rpm torque not higher. Just go with a 52mm tb it works just fine.

 

Don't bother. You are not maxing out your stock TBI unit, or even close to maxing it out. It'd just be 250 bucks out of your pocket and may even present idle issues on a bone stock car. I know a big 2" unit made it rougher off idle for me.

 

Stay with what you have. I bought one of those and on a stock tune you'll lean out and bog down when you mash the peddle. Your stocker is good to about 275 hp with the ultimate TBI mods.

 

Dont test your luck with that extremefi seller. He is a DISONEST THIEF. and his statements about his products are He doesent have nothing to sell that will make your car faster and stronger, exept the 350ci rebuilt.

With some research on tgo you will find out that your stock tb flows anough to fed up to 300hp.

 

Did you buy something from him and get screwed? What happenned? Enquiring minds want to know...

 

To the original poster: If you think you are going to buy that TBI unit and bolt it in place of your stock TBI unit without changing anything else and see any gains you are wrong. Not only will your restrictive stock heads and cam prevent you from being able to use the extra flow allowed by the bored out TBI units, it will completely throw your tune off and your car will likely worse than it ever did before. You just cant bolt on a bigger TBI and expect gains, thats now how you mod a TBI setup. It just doesn't work that way.

When do you need those bored out TBIs? If you take your motor down to the short block and install an aftermarket (or high performing GM cam), decent flowing heads, headers, full exhaust, maybe bigger injectors and/or a high flow fuel pump for increased fuel pressure at the stock injectors, and not to mention tuning. Even once you do all this and install the bored out TBI unit don't expect to get anywhere unless you learn to tune your own PROM chips.

What kind of engine is this going on? Tell us what car you have and what mods have been done to it if any. Then we can help you decide if buying a larger TBI unit is something that will help you. [never mind I just saw that you said it is stock. yeah, 'nuff said]

 

Yes. Wenn I bought mi 91 lo3 Firebird that was a real deception since its far away from being a muscle car what it should be...

I bougt one of Xtreme-fi's 46mm GM TBI 340HP throttle body kit, this Xtreme-fi LIER states you get a coustom TB for your specific Make and year,otherwise I wouldent have buy'd it. I did recieve a 46mm TB and the injector spacer, but the TB was not the same 87-92 lo3 thirdgen have. Sensors and vacuum ports were different and I did not whant to adapte everithing since I payd for a direct replacement. I also offered I could send him a 87-92 lo3 thirdgen TB to do the work. Extreme-fi THIEF then agreed that if I send him the TB back he will send me an exchange TB for my car.
I never recieved any exchange and at some point after I sent a complaint to ebay, he claimed the post lost it, I have pay'd for insurance but he doesent answer my e-mails. And since the claime was made over 20 days after the ebay sale, ebay and paypal cant help me and he has the right to keep my 250$.
I really tought that he may mispacked my order and that I will have no problem with him. But at this point it really loocks like Xtreme-fi is A DISONEST ebay seller.

I also installed the TB spacer and there is no gain of power at all. Xtreme-fi's feedback STINKS too. There is just NO WAY someone buy's one of his spacers, spends the time to intall it (30min) and then leaves a positive fedback writing his car runs better. I tooke the spacer off.

 

As far as the TBI's go, the way to see if you need a larger one is with a vacuum gauge. Take the air cleaner off the TBI to eliminate false readings and hook up the gauge and observe it during WOT. If the pressure drop remains below 2 in. Hg, then a larger TBI wont do much power wise. Your money will be better spent elsewhere.