LS1 Conversion to Carbureted LS1???

[27Cam04]

Sound interesting to read at Chevy High Perf. this month..Anyone have experinced with it? Good Running? Stronger run than LS1 EFI ??

[97LT1Z28]

I don't know anyone who has done it to a 4th generation f-body but I've know plenty of people who have done it to a 3rd generation and have had very impressive results.

[TraceZ]

removing the port FI to go with a carb would be taking steps backwards. The carb can be tuned to do any one thing well but not all at the same time like FI.

I really have no idea why anyone would take a motor with a very well designed FI setup and rip it off in favor of a carb.

The FI is easier to tune, runs better, gets better economy and makes more power. People spend tons of money to convert carbeurated engines over to FI to see the benefits. Why would anyone want to go the other way?

I think that the carb is what gets installed when money is an issue because it is less expensive. Most modern motors these days come with the FI included though, so I am really confused as to why someone would decide not to take advantage of it and spend extra money on a carb?

I can see an arguement to replace an older 3rd gen Throttle Body Injection setup with a performance aluminum intake manifold and 4bbl carb. Those TBI setups were good for crap. The carb is an improvement. Maybe that is what "97LT1Z28" was refering to. I would find it hard to believe that it is common for third gen owners to toss a TPI in the trash and replace it with a carb.

[DeWynter]

I for one can tell you after playing with my 68 GMC truck for a few years I was going to convert it to TPI just for ease of tuning and fuel economy. I couldnt even dream of tossing my TPI stuff in my 89' Formula for a carb! Even for an LS1

[RocKin1967]

they have made some seriouse HP with the carb on the ls1 withouts having to fork down some cash to reprogram the computer and then having to do it every other time the add another mod, and as to y people do it.... u would need a custom gas tank for the fuel pump and then the 400ft of wiring gets in the way n a few other things i cant remember right now but yea carbs dont suck

[94Z/28]

Theres nothing wrong with carbed LS1's Hot Rod magazine made 530HP with one a couple months ago, stock LS6 changed cam(dont remember specs), put a GMPP single plane intake and a 750cfm carb and knocked down 530. Dont get me wrong I got nothing against FI, but I like carbs. Also there is no doubt that the LS series of motors are the best small blocks ever

[Kevin - Blown 95 TA]

There are more arguments for making a carbed LT1 or LS1 race car than a carbed street car that has to go thru emissions and get good mileage, but a lot of it has to do with the difficulty of tuning the EFI and having the equipment and knowledge to make tuning changes. The stock OBD1 & OBD2 pcm can also be limited in the air flow it can sense, the injectors it can use, the rpm's it can recognize, and the transmission it can use. There are workarounds, but a guy might end up with a low impedance converter, an aftermarket igition, aftermarket or no transmission controller, etc. and just using the pcm to run the instrument panel. One of the biggest differences is that the EFI car can adjust for changing conditions & wear better than a carbed car with a distributor, and is capable of having a better tune, but when it comes to making power and racing, a carb might be a better choice in some cases. There are those of us who can program their cars to do what we want, but there's also the chance that the programming process will hiccup during transmission and the pcm then needs to be physically repaired, or make a mistake programming line pressures in an A4 and cause the clutches to burn up. There's very limited DIY info out there for the guys who choose to do their own programming and no support from GM. That gets kind of scary, along with the initial outlay for laptop, cables, and software, all of which is pretty expensive.

[Jeff_in_Atl]

I was watching an interview with a NASCAR official and he was asked why NASCAR didn't go to fuel injection. The guy said there are 2 main reasons. One is it is to hard to keep them from cheating. Two is they would pick up about 100 horses. That tells me that fuel injection is more efficient and can make more power. Doesn't top fuel use fuel injection?

[TraceZ]

There are more arguments for making a carbed LT1 or LS1 race car than a carbed street car that has to go thru emissions and get good mileage, but a lot of it has to do with the difficulty of tuning the EFI and having the equipment and knowledge to make tuning changes. The stock OBD1 & OBD2 pcm can also be limited in the air flow it can sense, the injectors it can use, the rpm's it can recognize, and the transmission it can use. There are workarounds, but a guy might end up with a low impedance converter, an aftermarket igition, aftermarket or no transmission controller, etc. and just using the pcm to run the instrument panel. One of the biggest differences is that the EFI car can adjust for changing conditions & wear better than a carbed car with a distributor, and is capable of having a better tune, but when it comes to making power and racing, a carb might be a better choice in some cases. There are those of us who can program their cars to do what we want, but there's also the chance that the programming process will hiccup during transmission and the pcm then needs to be physically repaired, or make a mistake programming line pressures in an A4 and cause the clutches to burn up. There's very limited DIY info out there for the guys who choose to do their own programming and no support from GM. That gets kind of scary, along with the initial outlay for laptop, cables, and software, all of which is pretty expensive.

If we are talking dedicated race cars, I agree that the carb may be the best way to go for your reasons. I was assuming the question pertained to a street driven car.

[97LT1Z28]

Trace Z . . . you hit the nail on the head.

Street or Strip? . . . . That is the question!

It's like Shakespere meets f-body!

[fastTa]

I will all depend on how serious you want to get. If you want to go all out, you throw your carburetors in the nearest dumpster. All the big boys are injected. Much more horsepower is available by using fuel injection, whether it be pump gas, race gas, methanol, or nitromethane. Fuel injection makes more power. If you are on a budget, sure a carbed setup will do in a pinch, but WHY?? That defeats the enitire purpose of having a race oriented head and intake manifold like the LSx motors have and all of the technology that has been engineered into the electronic fuel injection.

Yes there are some limiting factors with the stock PCM. For example, the stock LT1 PCM is hard limited to 7000 RPM. So again, it boils down to how serious you want to get.

Yes, top fuel guys are injected, but it is a mechanical injection. Most of the Pros have the fuel pump driven directly by the cam. As RPM's go up, so does fuel pressure and so does the amount of fuel injected into the intake runner and the hat.