1" Spacer TB spacer + VAFPR Injector pod + 80lb. Injectors + Injector Pod spacer + Ultimate TBI mods would free up how much horsepower?

 

You'll probably loose about 20-30HP.......unless you retune your ECM. If you're not tuning just swap your stock injector pod on top of a ported TB.

 

If you have the stock exhaust manifolds, intake and breather then I'd say you'll get very little from just the TBI mods. The engine is so restricted by those other things it won't be able to utilize the extra mixture capacity of the modded TBI.

If you put on an open element breather (or something that can supply some extra air) and retune the ECM, you might get between 5-10 hp from the modded TBI. At that point headers and exhaust would limit any more.

The stock TBI unit flows about 480-490 CFM with the injectors in place. For a 305 L03 that's making power under ~5000 RPM that really isn't a restriction at all. The L03 will only start demanding more mixture when it's allowed to breathe and rev higher - the stock exhaust and cam limit that from happening.

If you're not retuning the ECM then, like BMmonteSS said, don't use the bigger injectors. Your ECM will "think" that it still has the old injectors and it will operate them "incorrectly". Put your stock injectors back on with the modded TBI unit and it'll work (although, strickly speaking, it would still be a good idea to retune the ECM because your TBI will now be flowing more air). The Ultimate TBI mods can make it run a little lean, so it would be wise to increase your fuel pressure when you do the mods. If you aren't reading your ECM output, then you'll have to go by "feel" on this.

The bigger injectors themselves will not increase horsepower because the ECM - if properly tuned - will only "supply" the amount of fuel that the engine demands. If you don't retune the ECM, the bigger injectors will simply dump too much fuel into the engine. There is a small benefit to bigger injectors though ...they have higher capacity, so they respond more quickly under acceleration (acel enrich). When I put big injectors on my stock motor I noticed an increase in throttle response, when I added the other TBI mods it became more noticable ...an increase in fuel pressure with smaller injectors would have the same effect (perhaps even better because the fuel is under more pressure and the "atomization" might be better).

I realize that you never actually said that you were going to do the mods - you simply asked a "what if" question. I answered as if you were doing the mods because I think many people are interested in these types of modifications and having the info in one place might help someone who's searching the archives.

So, to end that ramble: On a "stockish" L03 with Ultimate TBI mods, bigger injectors are unnecessary and won't do a thing to increase power. Use your stock injectors with your modded TBI and bump the fuel pressure up a little. Save your big injectors for when, and if, you get a bigger cam and better flowing heads (or port your own).

 

Good info you'll save me $150 dollars for now Now all I need is to figure out how to increase my fuel pressure... And where to get a chip...

 

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go to the yard and pull a chip out of tbi equiped car and go to TBI CHIPS this guy will reprogram your chipoes to work with your mods for like 75 bucks. i also have a spare chip out of an 87 or 88 i believe.

 

TBIchips.com is junk just like all the other mail order chips. I've looked at his programming and all he does is advance the timing 4 deg, richen the fuel mixture (when it should be leaned) and disable vats, egr, and the speed limiter. I also thought that he was charging something north of 100$ now? You can have all the equipment to burn your own chips for 125$, I'll e-mail you a .bin file much like TBIchips....but not his exact bin for FREE.

 

Yeah I wanna get the equipment so I can learn... but the price I was looking at for equipment was adding up to $300-$400. Could you link all the necessary stuff your talking about. BTW I was adding my prices from the tuning starters guide.

 

thanks for letting me know i was thinking of getting him to reprogram a TPI chip for me.

 

yea im also interested in the equipment you have aquired for that price... please tell us... im an interested PROM n00b lol

 

Come on guys, it's the very first post in the stickies at the top of the forum. You gotta do some of the work yourself, myself and others (mostly others) have taken a lot of time to consolidate the basic info you need to get started moding your TBI engine right there in the stickies.

 

I've been looking around the net for a vacuum AFPR. I guess GM doesn't sell them anymore. Can anyone point in the right direction?

 

Got mine from someone on here and I am glad I did... $50 well spent!

 

The only hardware that you need to tune your chip is an 85$ burner from moates, a 30$ adapter to allow you to use the flash erasable chips, and 2 or 3 5$ chips, a data logging cable (5$ DIY or 45$ premade) and of course a laptop. You don't have to have the EBL, or an emulator.

 

Ok start posting up links because I got a total of $300 dollars for everything...

Wow just did a search thats much cheaper that pocket programmer...

 

Amazing what a little search can do isn't it

<u>DIY Fuel-Injection Tools:</u><br>Created by an EFI enthusiast for EFI enthusiasts like you! : Moates.Net

Thats all you need to know, if every company stood behind their product like he does the world would be a better place.

 

r0nin89,

First, Welcome to the world of TBI. Congrats on your first mod.

2nd, Please start doing some searches, read, read, read, read, and read more old posts... I have been on this board since 97 and I'm positive that EVERYTHING you'd ever need to know, everything you're thinking of doing to your car, everything related to TBI is covered somewhere within these pages. Granted the old search functions worked MUCH better, but you should still be able to find the answer to most of your innitial questions already covered.

The best posts in the world are ones that say... "I did a search, I read this post (post link) and I still have this question _____________.

 

Beleive me I always search before I ask questions I feel should be blatently posted somewhere else. The thing is it gets tiring after going through 3pages of posts that only came up because someone is selling their PROM equipment or someone made a one word mention too it in an exhaust post.

 

GM no longer makes a VAFPR? boy with all the marine engines out there. maybe just the rebuild kit is offerred. my aeromotive FPR is VAFPR. i chose not to use it. i tried using the GM as an alternative to tuning a while back.

 

the old search was so much better. I dont understand how when dirk owned the site he was able to get the search to work but now it wont.

feel free to im me at snflupigus or pm me anytime too.

I wasnt trying to come down on you or anything. Just make sure you were looking before posting.

 

A simple browse through the stickies here, and on the DIY prom board would net you about a week of reading and a month to comprehend it all.

 

I did the week now I need the month...scrap that 2months.