Thoughts on changing from TBI to Carb? Mud Bog Runners Chime in!

[MudFrog]

Ok, I used to primarily just run trails etc, but since I have joined my wheeling club I primarily only do Mud, thick goey Virginia red clay. They are very big into Mud Bogs, etc..

The reason I'm debating about going to a Carb is for HP. I am very limited with the type of engine I can build with TBI, and it would be much less expensive to buy a built carb'd 350 as opposed to a built TBI'd 350. Not to mention all of the computer issues. I know I would miss the TBI but I think the added power from a new engine would more then suffice for the sacrifice.

So what are your thoughts? How many people switched over? What would be involved?

89 K5.. btw

 

[sled_dog]

Fuel pressure regulator, lose the computer and computer distributor. Just buy an MSD distributor from Summit, should be like $120 and got a good quality one to replace that computer one. Then all you need is the motor and carb. If you want to put a carb intake on the TBI motor(if you want HP this will make more than TBI but TBI heads suck for flow so its pointless IMO), just slot the 4 center bolt holes so you can put a bolt straight down instead of on the angle of a normal carb intake. But like I said, just get a fuel pressure regulator and run the in take fuel pump with the carb. No mechanical pump robbing your HP off the cam.

 

[MudFrog]

Will lower gears help out a lot with mud? I'm putting in some 5.13's with tax returns, I'm thinking if I have 5.13's I might not need a real real high horsepower motor for the mud.

Tax returns = 5.13's and possibly a new cam + Holley Projection 670cfm to make sure my motor is not starving.

Any problems with adding a cam to an engine with 70k?

 

[k20]

a lower gear is going to make the motor spin more rpms, so theoretically it limits wheelspeed. However, if your motor isnt capable of spinning the tires now, it will help get em spinnin. So if you have a high output motor now, it probably wont help (unless you are runnin like 3.73's and 44's), but if the motor is weaker, it will help.

 

[CHEVY 4WD]

I run a carb.. and have good HP im in favor of the old faifull Q-JET it good up well into the 400+ HP range. As far as gear I like to stay a little high for mud you dont want your motor to be wound out all the time... but before you re-gear keep in mind what you plan on doing with the motor. Wheel speed is a good thing in the mud for heavy trucks

 

[bigyellowjimmy]

If we lived closer I'd trade you the carbed 350 in my Jimmy for your TBI engine

 

[MudFrog]

Well at the moment my 350 is bone stock, so it is deffinitely a dawg with 38.5's and 4.10's. I'm thinking of 5.13's primarily to get some "cheap" pep out of my truck. If I do what I want to my current engine then I would only be pushing around 275 hp or so. If I get a carbed 350 I would be looking for around 400 hp.

So I guess I will go ahead and do the gear swap and see how things go with my stock 350. If I don't like it then later down the road I'll swap again and put a carbed 350 in.

 

[AkMudr]

From goin to the VA bogs up in Richmond...everyone seems to be runnin high HP and carb.Gears arent generally an issue if youve got the balls to move but I know alot of guys run there rigs in the 4.10-4.56 range...and thats runnin the different classes with 35's, 38's 40's and bigger.

 

[84_Chevy_K10]

I'd suggest you get a Dana 60 before you start talking about gears, engine mods, or anything else.

 

[AkMudr]

I'd suggest you get a Dana 60 before you start talking about gears, engine mods, or anything else.

Good call. If yer gonna run the bogs, specially in VA, you dont wanna show up with anythin less than a D60, 14BFF and detroit. I saw quite a few folks last year get towed out from a busted rear end. Or a snapped front shaft,ujoint or hub. Most breaks occured when going over the first "jumps" in the bog then landing.

HP+Air Time= breakage.

 

[Wingnutt]

Deleted please remove

deleted

 

[Wingnutt]

Hey there frog, long time no see.

From strictly a power standpoint, you can make a bit more power with a carb and you can tailor the power to a specific rpm range with the cam and intake. BUT before you start ripping things off, remember that we have that stupid emissions part of the state inspection. I haven't talked to ya for a while, but have you done anything with the computer chip yet? I've been playing around with mine for several months now and have gotten some pretty good results, and that was before I put the 4:10's in. OR, you could but a pre-emmissions vehicle and let your imagination run wild. Give me a yell sometime, I would like to get a trip together with some of the sw VA K-5'res.

 

[dyeager535]

I was going to suggest similar...don't discount TBI yet.

I'd suggest looking at the thirdgen.org TBI forum, but the site was still down last I checked.

I guarantee some of the TBI motors people are running there are making a lot of HP, and they did it themselves.

 

[MudFrog]

A high horse TBI motor would be fine except it will cost a whole lot more as opposed to a carb'd engine.

A dana 60 will be in the works soon enough but for now my front 10 bolt will do fine (it has for 2 years now). We have mud pits and bogs here local but nothing like in those pictures

Currently I have a 14 bolt rear with detroit, 10 bolt front and 4.10's. The truck just can not produce the power to turn the tires in the mud. Soupy mud it will do ok but thick gooey clay does not. The last bog I went to my club members were asking why I wasn't giving it much gas, they were amazed when I told them my foot was on the floor. It just will not turn the tires in the thick mud.

Wingnutt, deffinitely got to go wheeling. I have to get a new steering box and change out a ball joint before I hit any trails but hopefully within the next month or so I will be back up and going.

 

[dyeager535]

You gotta spend money to make power, doesn't matter if carbed or not. Thats a universal constant. The fuel delivery system is just as important, maybe less, than the components chosen like heads, cam, exhaust, etc, and you can spend serious money on that stuff.

I can't think of anything other than a different throttle body and PROM burning stuff+ time, that a carb wouldn't require to make good power.

As expensive as "good" aftermarket carbs are, I'm sure TBI isn't really THAT much more expensive.

Of course, thats from not seeing what aftermarket throttle bodies cost, ane whats required for what level of HP.

 

[AkMudr]

. We have mud pits and bogs here local but nothing like in those pictures

You wanna see how folks build there trucks..come on out to the bogs in Petersburg....(with the exception of a few backyard built rigs)

Petersburg is about 3 hours from yer place. Alot of guys I go up there with drive the 3 hour mark just to go there and its totally worth it. First bog is March 19th.

Heres the schedule

http://www.virginiamotorsportspk.com/mud_schedule.htm

 

[MudFrog]

I'll see if some buddies want to make a trip up there to check it out.

I know serious HP requires a lot of money, but like I said, if I do the gears I'm probably only going to need around 275-300 out of my engine, if I go to a carb engine I will look for around 400hp. I can reach those #'s without a serious amount of money put into the engine.

I figure:
Holley Projection 670cfm - $300
Vortec Heads - $300
Mild Cam for TBI - $180 (not sure on which yet)
Intake for Vortec Heads - $250
New Fuel Pump - (haven't checked prices yet but I would assume $130 or so)

So I'm thinking these engine mods with lower gears would be a lot better than my stock 350 and 4.10 gears.
Thoughts?

 

[SUBFAN]

Leave the gears alone and build a fire breathing 383....If you go the carb route, make sure the regulater has a fuel return, so it won't burn up the pump. The new Holley truck avenger looks like a very interesting carb....


Eventually you will need that front axle, and it would suck to have built 2 of them....

 

[MudFrog]

There are carb'd 454's on ebay between 2k-3k claiming 400+ HP. Anyone have any thoughts on those?

 

[MudFrog]

Ok, finally figured out what to do. I still do trails and all so I want a decent all around truck that will do good in Mud.

Getting a D60 front, putting 5.13's in and will do the mild upgrades to the current engine.
ProJection 670cfm
Vortex Heads
Cam
Intake Manifold
and the little stuff in between