I was originally considering a custom turbo setup, but I am starting to lean toward a supercharger due to the fact that I can keep my AC and smog equipment, and there will be less design hassles, less heat in the engine bay (hopefully), etc. I still am not going to buy a kit, because for what a kit costs, I can make my own inlet and discharge tubes, and make my own oil lines, etc.. and save some money. I would have had to do the same thing with a turbo.

The engine in question is a 350 truck block with 4 bolt mains, Scat crank, Scat rods, SRP pistons, TFS 23° w/195cc intake runners, and a high-flow TPI setup (will probably be switched to a Stealthram, eventually).. basically, it's a budget buildup. The compression ratio is almost 10:1 (actually around 9.8:1), but I also live at 5500 feet, so I feel that it needs that much compression to stay responsive, and it won't be a problem with moderate boost.

The fuel system side of things is being taken care of, the only thing left that I need to decide on is whether or not I should go with the larger compressor, or if I even need the extra airflow. It's a street-only car, and I plan to run ~10lbs of boost or so. The T-trim looks like it flows a higher volume of air at the same boost levels, and actually has a higher max boost level, not that I'd ever need 26psi (Ok, who am I kidding, I'm sure the potential to do that would be nice ). But, for my moderate boost levels, and considering my thinner air, I'm thinking maybe the T-trim would be more efficient and not heat the air as much.. I won't be running an intercooler, maybe water injection or a small shot of nitrous down the line, but nothing other than that.

Is a T-trim going to be too unfriendly for the street, at moderate boost levels? Cost isn't a factor on the head unit, my cost on them is actually very similar.

Thanks guys.

 

Maybe all the hardcore supercharger guys are sleeping or something..

I'm just mainly wondering if I'll really hurt myself with a bigger head unit.. I can't see any drawbacks, but that's why they pay you guys the big bucks. More airflow = good, right?

 

I would recommend the S-trim. For your 9.8:1 compression ratio, and for street use, it is a hard combo to beat. The T-trim is nice, but also produces some heat! Check my sig. I ran my S-trim at 15psi with 10.5:1 compression and never had issues. Either unit is fine, but I would say get the basic S-trim kit and just upgrade to some nice 8 rib pullies for more boost.

Stay simple, stay happy, believe me!

 

One thing to note about GMI FAST setup is that he had full control of his fuel/timing (DFI) which helps keep things liveable in the engine

you can do the same with PROM burning but it would be alittle more difficult

 

Ive seen some back to back tests of the s-trim and the t-trim on the same engine and the graphs were the same up till around 18psi of boost and then the t-trim started kicking in. It made more power but it was all on the top end of the efficiency range.

Id say go with the s-trim. Cheaper, and it will do what you want.

 

I have some connections, engine management and dyno tuning is on the "to do" list.

That is very good to know guys. I know my engine will never see 18psi and higher. I guess I need to start seriously considering the S-trim.

 

Yeah I asked this question awhile ago. Then I saw a 383 4th gen with an S-trim in the 9's with 10lbs of boost. I made up my mind there.

 

Ya, a local club member is running 9's in his 4th gen with an S-timmed, aftercooled 383. He looked at the T-trim, but as Guido mentioned, all it's benefits were much higher in the boost curve than he was pushing anyway. It also generated more heat than the S-trim at comparable boost levels.

Of course, now the guy is fabbing up a YS trim and a front mount intercooler. High 9's just weren't cutting it.

-Matt