13bcosmo

I was thinking of converting my S4 turbo engine over to a single throttle body instead of the mazda item. I have a single unit the measures 80mm, i think it will give more flow then the mazda item and maybe a little less restriction. Would like to hear people ideas on this and if anyone that has done this how they found it?

13btnos

iTrader: (1)

I have a 80mm LS1 throttlebody on my intake. Don't know how it runs as I haven't finished it up yet. It's on a S6 FD intake and the plenum is opened up to accomdate the single blade. I joined all three holes to make one open plenum. My friend made 580rwhp with this setup but from what I gathered you will lose some low end response. Which only affects you if you use it for street use. My car will only be ran at the track so the low end response is not an issue for me. Couple shots of my intake setup.

rotarygod

iTrader: (1)

^that is absolutely true. I had a 75mm Mustang tb on a modded S5 intake for a while. You definitely do lose some low end power and street drivability. This al has to do with air velocity through the tb. Remember that you for all intents and purposes have a dual plane manifold right now with the primaries separated from the secondaries. The secondary plates don't even start to open until you pass about 20% throttle. This means that all of your air up to that point which includes crusing speeds is going only to the primaries. This keeps velocity higher and chamber filling better. Since we have 3 throttle plates stock, all the air to the primaries goes through 1 little plate while all the air to the secondaries goes through 2 plates. The secondaries breath better but this is really only evident at higher rpm's when flow through the primaries is getting maxed out. Just because there is a turbo on the engine does not mean that when the primary maxes out it will force the rest of the extra flow through the secondaries. This would cause a pressure imbalance in the manifold and that just can't happen.

When you hog out the dynamic chamber into one larger single plane plenum, you let all the ports share the airfow from the same spot. This would even work the same way if you hogged out the plenum and stil used the stock throttlebody. All the ports would be sharing from all 3 plates. Top end would still benefit somewhat and drivability and low end would still suffer. When I had mine, it was fun for a while but I got tired of it pretty quickly. Mine is a play car but it is a street driven playcar. I liked the drivability of the stock setup better. That's just a personal preference though.

While I did rig mine up to work with the stock ecu and tps, it was far from optimal. There's not alot of point to doing it without a standalone ecu. I also found that 75 mm was too large and that a smaller one would have been nicer. 80mm is way too big unless of course you are putting down 500+ hp on a race engine.

13bcosmo

Thanks for the info guys, that was what i was starting to think to, that the low end would suffer quite badly. My car is going to be street driven and im only aiming for 350-400rwhp soo i think i might stay with the standerd setup. As for the standerd setups i have a S4 engine, is there much benifit to changing over to a S6 intake setup i have heard it is not that had to do, i will also be running a standalone ecu so the tps wont be a problem.

sillbeer

I had an 80 mm infinity TB on my 20b. As said before you will loose low end response and gain top end.

-Destin

GT1-20b

13btnos,

Just an observation, I would centainly consider relocating the Injectors to the engine side of the Intake.
The heat rising from the Turbo & DP. will play havic on the fuel dencity.
This will have You chasing your tail on the tune-up, not to mention, percolation, injector heat soak, and a fire hazard.

Though it makes for a much "easier" instalation, the way it shows on the pics.
The benefits of relocating the injectors to the other side, far outweigh the inconvenience of re-doing it all over again.

GT1-20b

PDViper77

iTrader: (9)

A thick heat shield should do the trick.

13btnos

iTrader: (1)

I got the intake from a friend of mine and was already setup that way. So I will leave it the way it is but I will be doing some extensive heat shielding. The exhaust will be totally wrapped and the exhaust side of the turbo will also be shielded and I will also have a shield up against the injectors/lower manifold to keep the heat off the manifold and prevent heatsink. I've read all your post and know about your quest for thermal efficiency and it amazes me how many people don't consider these things when building a turbo anything.

GT1-20b

Wraping doesn't help, just fools people into false security.
When using "FUELS" , One get's a much larger "WINDOW" of tuning, before the sh--t hits the fan
w/ pump gas, ...You don't get that opportunity. .........

All the best,

GT1-20b