Scottie-GNZ, i need some suggestions (long)

[Guest zthang43]

Well, it looks like everybody else is posting questions for you so I will too.

What turbo(s)? did those GN's come with stock? Weren't the early ones a carb blow through setup? What were the main issues with that setup?

Also, how much boost were GN's running in stock form? Are the turbo's still easy to find for those, or are there other similar turbos that are easy to find?

I ask because I'm considering a turbo setup for my 4.3 V6 in my 74 Z. I know I should probably ask the Sy/Ty guys but nobody here seems to have done a Sy/Ty Z. I haven't decided about twin turbo or single turbo yet. I'm not going for huge power; I plan on building up the motor a bit more to make 300 to 350hp n/a, and want to add a turbo setup to get about 450 or so. It seems that I should be able to do this with relatively low boost, (I'm guessing 10psi or a little less?) so I want to have a turbo that spools pretty quick.

What would you suggest?

I would like to do the turbo side of the buildup relatively cheaply, as I will already be spending enough on the motor itself. (Intake, heads, head work, headers, pistons, rebuild, and 4 bolt main conversion.) Can the turbo setup be done for $1000 to $1500? I was thinking if I can find some reasonably priced used turbos that would be reasonable. Besides, for about $2000 I could just go with a ATI Procharger for that kind of boost.

Anyway, sorry for the long post, any suggestions, ideas, or advice is appreciated.

Dan

[Scottie-GNZ]

Well Dan,

 

you decided to ask a mouthful, didn't ya?

 

What turbo(s)? did those GN's come with stock? Weren't the early ones a carb blow through setup?

GNs came with a variety of T3s. The early ones were carbed, the 84-84 were non-intercooled with the turbo mounted right up on the intake and the 86-87 were intercooled with lots of improvements.

 

What were the main issues with that setup?

The early ones had a carb . The 84-85 were not I/C'd and you were limited in the mods you could do. They are not a good base for making 450HP.

 

Also, how much boost were GN's running in stock form?

I am more familiar with the I/C versions and they ran 12psi from the factory.

 

Are the turbo's still easy to find for those, or are there other similar turbos that are easy to find?

I will only address the 86-87 as I feel the early setups are not worth pursuing unless yiou have one already. The 86-87 used a 3-bolt turbo unique to the GN. No problems finding one in the Buick community. You can go a long way with the stock tturbo but is not the way to go for 450hp.

 

I ask because I'm considering a turbo setup for my 4.3 V6 in my 74 Z.

The GN and Sy/TY engines are both V-6 turbos but worlds apart. The 4.3L is a 6-cyl SBC and nowhere as strong as the Buick 3.8L. A stock unmodified 3.8L can handle up to 550hp w/o detonation but why risk it. Nothing is interchangable between the 2.

 

I haven't decided about twin turbo or single turbo yet.[/qoute]

For only 450hp, a TT is not worth the effort or expense. I am close to that right now with a special hybrid turbo and no engine mods. Focus on the heads, a mild cam and the right turbo to match and 450rwhp is no problem. Note I said RWHP.

 

I plan on building up the motor a bit more to make 300 to 350hp n/a, and want to add a turbo setup to get about 450 or so.

Problem with this approach is that you will need a decent c.r. and cam to make 350hp with the n/a and that is the opposite of what a turbo needs.

 

It seems that I should be able to do this with relatively low boost, (I'm guessing 10psi or a little less?) so I want to have a turbo that spools pretty quick.

If having a 450hp turbo engine is the end goal, I would build the n/a with all the parts needed for the turbo in the shortblock. Do the heads, get the correct turbo cam and low c.r. pistons for the turbo setup and run it n/a until you are ready to switch to turbo.

 

I would like to do the turbo side of the buildup relatively cheaply....Can the turbo setup be done for $1000 to $1500?

Hate to tell you this, but it probably will not be cheap. It is a lot more expensive trying to piecemeal a turbo setup. You best bet is to find turbo parts off a Sy/Ty but the electronics is not the best.

 

(heads, head work, headers, pistons, rebuild, and 4 bolt main conversion.)

In my opinion, you might be better off searching for a complete Sy/Ty engine, go with that stock, then over time, get an SDS and a T04 and GOOD I/C. The 4.3L is not a strong turbo engine but what makes them break is the fact that the engine management system is not conducive to modifications, the I/C is not efficient and owners try to push too much boost through them. With a good I/C and a programmable, you can avoid detonation and safely run more HP. Remember, it is detonation, not boost, that breaks engines.

 

Probably not what you wanted to hear, but I do not want to see you charge into a project w/o the right budget. Whatever you budget, ADD AT LEAST 25%, repeat, ADD AT LEAST 25%.

[Guest zthang43]

hey thanks scottie. I appreciate your input. I'm still trying to figure out what's feasible and practical, and whats the best way to go.

In the end, I may end up just using a Procharger like John Scott's setup, but turbos would be cool.

[Guest jens]

You should join the s-series forum. Bill mach from www.machperformance.com has worked with both supercharged and turbo v6. The vortec engine has better heads and rods than the L35 and should be good to 450 crank hp. The L35 rods has a lower rpm limit this means you might end up reaching the rpm limit

in a 1/4 mile run with a datsun rearend like scottie did. A vortec s10 with cmfi injection can get close to 300 rwhp with bills kits. A t3 with 60/0.82 trim like some buick and pontiac 301 is to small try this calculator

http://www.sn95.com/projects/turbo/part1.htm