Redneckmudslinger
Registered Member
how much involvement would it be what would i have to do
CK5
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tbi to carburetor swap help
- Thread starter Redneckmudslinger
- Start date
Redneckmudslinger
Registered Member
sorry i didnt see them websites into now thanks for the help
Yanking off the TBI and throwing on a carb isn't going to do ANYTHING to make more power.
People aren't trying to be jerks about telling you not to yank TBI off. Many times people do it without thinking the whole thing through, and some have been around long enough to know it can be a mistake, especially when done for the wrong reasons.
If you want to make power, just ditching the TBI isn't going to get you there. You will incur a bunch of expense and time and still end up with a motor with garbage heads, garbage cam, and garbage exhaust, none of which do anything other than make low end power, which TBI is arguably BETTER at than a carb.
Go look up any 400HP 350 build out there. I can't think of one that reused the factory TBI cam or heads. If you are building a high HP motor, absolutely the ~525CFM restriction of the TBI unit is going to prevent you from making power, but without changing everything else, the restrictions elsewhere are still an issue.
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Redneckmudslinger
Registered Member
i gotcha so would it just be better to buy a used 350cid motor and sell the tbi cause i seen alot more horsepower ci motor then tbi motor instead of wasting money on the tbi or could i make good power with the tbi
Redneckmudslinger
Registered Member
is there a website just mainly for tbi performance because i want power it just seems like the tbi has alot of negative things when it comes to power idk im new to this tbi thing i never owned one into i bought this blazer
Honestly not sure what the limit is on the 525CFM throttle body and the stock injectors/pump. The TBI systems are popular enough that with some googling I'm sure you could find out the theoretical limits.
One thing you might do, depending on where you want to go, is try some headers. They are normally worth a fair bit of power, often don't make enough of a difference to throw fueling off a whole bunch (so not likely to NEED a retune, although it would help) and would be usable on any other small block you end up with.
Honestly, if you wanted to make a fair bit of power, didn't want to bother with re-tuning, and all you cared about was weekend fun with the truck, a carb would probably suit you fine. But that is assuming the rest of the components were good enough to take advantage of the increase in air/fuel a larger carb could provide.
What gears and tires are you running? Is there a possibility that you could use some better axle gearing? My experience with TBI is that as long as gearing was good, and tire size was appropriate, it had respectable power.
One thing you might do, depending on where you want to go, is try some headers. They are normally worth a fair bit of power, often don't make enough of a difference to throw fueling off a whole bunch (so not likely to NEED a retune, although it would help) and would be usable on any other small block you end up with.
Honestly, if you wanted to make a fair bit of power, didn't want to bother with re-tuning, and all you cared about was weekend fun with the truck, a carb would probably suit you fine. But that is assuming the rest of the components were good enough to take advantage of the increase in air/fuel a larger carb could provide.
What gears and tires are you running? Is there a possibility that you could use some better axle gearing? My experience with TBI is that as long as gearing was good, and tire size was appropriate, it had respectable power.
Redneckmudslinger
Registered Member
ok one thing about the headers how can u put long tube headers on the tbi because if im not mistaken does the tbi have o2 sensor how can u put long tube headers on without hookin the o2 sensor up cause normal headers dont have o2 sensor holes right is there ways to by pass them or somthing like that
Redneckmudslinger
Registered Member
im running 35s with 4.80 gears
Redneckmudslinger
Registered Member
im sorry i ment 4.88 gears
That sounds like a decent combo, certainly doesn't sound like the tires are hard to turn!
You don't want to bypass the O2 sensor. If you are to that point, yank the whole TBI setup off.
Not sure who, if anyone, sells O2 sensor ready headers for the trucks, but if nothing else, bungs are available and can be welded in. Even if you ditch the TBI later, you can just run a plug in the bung.
It does seem odd that very few, if any, sell O2 ready headers, when there are no more carbed trucks made in this country. Header companies that don't sell any, are really limiting themselves IMO.
I will be getting Stainless Hedman's eventually, but even being stainless and uncoated, they say I will void the warranty by welding a bung on them.
You don't want to bypass the O2 sensor. If you are to that point, yank the whole TBI setup off.
Not sure who, if anyone, sells O2 sensor ready headers for the trucks, but if nothing else, bungs are available and can be welded in. Even if you ditch the TBI later, you can just run a plug in the bung.
It does seem odd that very few, if any, sell O2 ready headers, when there are no more carbed trucks made in this country. Header companies that don't sell any, are really limiting themselves IMO.
I will be getting Stainless Hedman's eventually, but even being stainless and uncoated, they say I will void the warranty by welding a bung on them.
Redneckmudslinger
Registered Member
no i havent cut them off but i was just wondering but thanks for the all help
Additionally, if you do it right (that is, yanking TBI out) you can probably find someone that would be interested in the setup, but it's gotta be complete, not hacked up. Kind of hard to do in a truck you don't tear all the way down.
Simple O2 answer is to weld the O2 bung in the collector instead of the header. Easy deal...
I understand that not everyone on this site is an actual wheeler. I know some just like a camping rig, or just think square body chevy's are cool and that is it. All of this is fine....but I still feel like this will be a mistake. In the end, it is your truck, and anyone can do whatever they want with their truck to make them happy. But everything that is said in this thread is advise from many, many years of experience. You said you are young...I remember when I was in high school or very shortly after, I thought I knew what I wanted in a truck and what was cool, but after a couple years of really looking (without the aid of forum sites like these where I could have learned faster) I realized what I wanted was really stupid.
I think the people in this thread that are giving you a hard time about doing this are feeling the same way. Once again, do whatever you want with your truck, but I can bet you money that if you still have your rig in a couple years, and you do go through with this swap, you will start kicking yourself realizing it was not a smart move.
I think the people in this thread that are giving you a hard time about doing this are feeling the same way. Once again, do whatever you want with your truck, but I can bet you money that if you still have your rig in a couple years, and you do go through with this swap, you will start kicking yourself realizing it was not a smart move.
y5mgisi
1 ton status
Leave it TBI. There is a reason 1987's are more desirable than an '85 or an '86........
Martin
Martin
wasted wages
1 ton status
sorry..... But I grew up in the era of "building" engines to make HP...not tuning an EFI one that came out of the factory....just look how many threads there are on EFI problems...ECM/chip issues with a cam swap... no thanks...I got better things to do.
I know the in's and out's of pretty much any Carb out there...I'll stick with them.
Yes EFI is nice and I'm not knocking it at all... I even had a thought to put EFI on my BBC when I had the blower on it... but it was so cost prohibited...
4500.00 was about what it would have cost me...
personally,,,I rather just run carbs off road.... my old QJ worked fine on Widow Maker.... and whats that?? about an 80° incline ??
I'm just skimming here..
OP, you'll want a heated O2 with long tubes.. as said, welded into the collector..
original line of thinking of OP... TBI has nothing to do with power per se.. it's fuel induction, that's it.. doesn't matter if it's TBI, MPFI, carb or Cletus sitting on your motor pouring a can of gas down the intake, it's not what dictates power... your cam, heads, compression dictate how much power you make...
and yes, if you want power, headers are #1 on the list of mods.. next you'd need to look at the cam... and that's where EFI becomes a bit more challenging, tho worthwhile...
OP, you'll want a heated O2 with long tubes.. as said, welded into the collector..
original line of thinking of OP... TBI has nothing to do with power per se.. it's fuel induction, that's it.. doesn't matter if it's TBI, MPFI, carb or Cletus sitting on your motor pouring a can of gas down the intake, it's not what dictates power... your cam, heads, compression dictate how much power you make...
and yes, if you want power, headers are #1 on the list of mods.. next you'd need to look at the cam... and that's where EFI becomes a bit more challenging, tho worthwhile...
Yeah, I'll concede that a carb is a good choice for a drag race (mud/sand/strip) vehicle, but if you want something to perform in all conditions, wherever you want to drive, like cold starts, heat soak, elevation changes, etc. then you need EFI.
We're pretty much all here to do whatever we want with our vehicles. If we were conformists we'd be on ColoradoCamrysandPreludes.com
We're pretty much all here to do whatever we want with our vehicles. If we were conformists we'd be on ColoradoCamrysandPreludes.com
This is a response for the OP, if he is still out there. Not to start something, just another way of looking at it.
You took the time to learn how to work on carbs. There are plenty of people here and elsewhere who have problems with carbs. Learning to tune one or the other is no different other than the way tuning is accomplished. The theory is fundamentally the same: get the right amount of fuel into the engine at the right time. Carb or EFI is fairly difficult to dial in for day in day out driving. Max output in a very narrow RPM range is pretty easy with either.
It would be a stretch to say that a low-end carb or carb rebuild is as costly as getting into tuning EFI, but when you start talking about higher end carbs, it is every bit the same cost, if not less, to tune EFI than to swap in a carb.
As has been stated, when you own the truck, it is yours to do as you wish. Take all the advice given, apply it to your situation, and make your own decision!
