camaro1122

iTrader: (1)

Its finally coming down to the days of tuning. Ive spent the last year puting together and building my turbo system. I did order a bunch of 12 gauge 304 stainless piping to redo my hack job piping i have now. Just some opionions on what i should do, i have a shop here that will tune and dyno my car along with looking over my work. I dont know how much the bill will be, they just said to bring the car in. Now my issue is they have openings next year which means my car will be sitting in the garage for the next month or more. Redoing my exhaust system should take more then two weekends if the welding shop can get to it. How hard would it be to tune and get a carbd 350 engine started and then running just to get on the dyno for the more exclusive tuning? I have a hei type distributoe with an msd digital 6 box. A holley 700 dp blow thru carb. Just opinions to see if i should even bother messing with it, ive never done it before but with everyones help here and maybe other fourms i could do it. What you think?

vortec350s10

Well to give you an honest opinion it would be nice to know a little more about your setup. If you don't have a wideband O2 sensor on the car yet I wouldn't want to run any boost to it yet, especially if you have never ran that carb before. I kept my carb setup the same when I first started bringing boost into the picture and it was incredibly leaner everywhere above idle. I know some guys just bolt on a blow through prepped carb and 'give-r' but I wouldn't risk it. If all you want to do is get it running so you can drive it somewhere I wouldn't worry about the tune. Just remove the WG spring and drive it easy. I would setup the timing like stock until you start adding boost. Then start limiting your max mechanical advance to keep it on the safe side. With no boost I ran 34 degrees, a max of 30 degrees timing with 3 psi, 27 with 7 psi, and 25 with 9 psi without detonating (as far as I could tell). I'm running cast pistons and ran my turboed car hard all summer with no issues so I think I've got a little handle on tuning, although I've never stopped learning. Keep your A/F ratio in the 11's to be safe and go from there. Compression ratio, fuel octane, intake air temp, boost level, air fuel ratio, and ignition timing are all factors that determine the detonation threshold of an engine. By decreasing any of these variable, others can be increased to a certain degree (no pun intended). If you are familiar with carb tuning and ignition curves, etc and have a wideband to monitor A/F, you can certainly tune it yourself. One mistake by changing a variable too much is all it takes to do engine damage, as you probably already know. So sticking with what you know is a conservative tune and seeing what changes do what is a great way to build experience and save money from just handing your car over to some shop so some other guys can tune it. Then you're the guy that knows the most about YOUR car and you can mess with it all you want till you think it's perfect or exactly how you like it, something a shop would never have the time or ambition to do. Hope this helps a little.

camaro1122

iTrader: (1)

Just the person i was hoping to hear from. Thank you. Yes i have a wideband o2 gauge. My setup is an ebay t70 turbo, i have two 38mm wastegates im going to run with a 7.4 psi spring. My carb is a 700dp with the jetting size you have and told me you had best results with. A msd digital 6 box, 3" intercooler plus 3" piping, walbro 255 fuel pump with stock lines and a regulator. As for the engine, it is completely stock except with a comp cam 262h and the springs,lifters, etc. engine is a goodwrench 350 truck replacement, only thing swapped is the heads (062 vortec) from the engine you have which is the 330hp chevy replacement engine. compression im guesssing is around low 9's. i love learning and doing things myself, but when i dont know how to do something i dont mess with it. Since this shop is backed up for over a month, i thought id give it a shot if i had enough help. Since i have no one to actually show me or teach me, im on my own. I learned how to drop the distributor in along with getting the fire order. If you got your carb setup running, i thick i can. Especially how similar they are