Quick spool, big top end 68vvt/88mm

[mike diesel]

Not having a whole lot of people interested in buying my 88mm so now I am starting to rethink the valley charger.

I had my stock turbo machined out for a 68mm compressor, has been sitting in a box since. Other than the 68mm compressor, the turbine side is totally stock.

I am curious how it would react with the 88mm (88/112/1.23ar) basically a gt5518.

I could care less if the truck goes faster than it already has. I know it isn't an ideal match in turbo sizing but if it will work I'd definitely like to give it a try and eventually swap it out for a stg2r.

What got me curious is I saw Harbin run very impressive times with a totally stock lmm turbo in the valley. I just feel like my compound setup is very under utilized and if i can get the same work done with a smaller setup whether it be the atmo or the secondary, I'd be all over it, and considering I already have the 68mm stocker it makes it easy to justify doing.

 

[mike diesel]

I could also port/polish, add some better vanes and a 10 blade turbine in to spice the stocker up a littler more if it will make it "worth it". I am just not sure if the 88mm will be severely limited with the somewhat stock charger in the valley.

 

[Rancelot211]

Ask mark he will be able to help you.

 

[mike diesel]

I will pick his brain beginning of the week if he doesn't add anything in here.

 

[Harbin_22]

Not sure if you want to spend the money but my truck was honestly lazy feeling with the stock turbo in the valley after having the 72R turbo on it. These R turbos are insane on spool. It did run good with the stocker 83 setup though. Was kind of scared to push it hard with the stock turbine.

 

[Harbin_22]

Maybe gate around it if you are going to keep the stock turbine

 

[yellowchevy]

Porting/polishing the exhaust side, 10 blade turbine wheel, and vanes will make a good difference and really wake it up.

I rebuilt/ported/polished my cousins LLY and it made a big difference; spooled much quicker too. I keep the stock comp wheel, turbine, wheel, and vanes. It just had an edge chip, stock exhaust, and EGR delete.

You'd be surprised how much material I remove and the difference porting/polishing makes.

Being you're just seeing how it would work, I would just leave the turbine wheel and vanes to make sure you'd like it.

Yellowchevy

 

[mike diesel]

Is that 10 blade turbine any tougher than stock? Or would the gt40 turbine be minimum you'd want?

 

[TwiztedMetal]

If you end up doing that set up let me know how it works I want to do the same with a dp72

 

[delong_1]

I wouldn't run it with a gt55 the atmo will be pretty lazy

 

[TROJAN366]

I would think that 88 would respond much better with a bigger valley charger. I would think the 72R would be the best option as far as VGTs go unless you were willing to gate around it.

 

[yellowchevy]

Is that 10 blade turbine any tougher than stock? Or would the gt40 turbine be minimum you'd want?

Shaft diameters are the same if its a stock, 10 blade, or 4094 turbine wheel; just requires machining on the exhaust housing to make the 4094 turbine wheel fit due to the larger blade diameter.

Being its the high pressure turbo I think the 10 blade would be fine but I'm not a twin master.

Yellowchevy