throttle body
 

I have a few questions about throttle body and want to see if the Twins family can help me make my decision.
1) would I benefit from an upgrade in the throttle body without going force induction? I already have the cold air intake upgrade.
2) if yes then which on would you recommend? I was looking at the Grams 72mm unit.

What other engine mods do you have?

it doesn't add power (maybeeeeee +1hp at best), just better throttle response for the most part

the only thing I have done is install a cold air intake but thinking catback and unicip tune after the throttle body. reason is the grams 72mm is only around $400. Doing the cheap upgrade first then go up the list just because of budget.

Would it help with the stupid 4k rpm dead spot?

Nope. Tunes will. I would suggest OFT or investing in Ecutek if you plan for boost down the road.

The best gains IMO are heads, exhaust and tune for NA.

The OEM throttle body is already oversized for the engine's needs. Even for mild FI, it's perfectly adequate. If you were going with forced induction and it was becoming a point of restriction, then sure. Otherwise it's money that could be spent on things that make a noticeable difference instead.

You'll have a much better result from a catless header and tune.

Spending money on the wrong things. OFT alone will decrease the "dead" spot.

I live in CA so catless header is not an option for if I want to pass smog.

The guys that replied don't have a personal experience. They haven't changed their throttle body. Personally, I changed it and I am very happy with the results. However, I am using a Toda Racing TB. Results may vary with the Grams unit. You will not see massive gains, but this is pretty much the same for most of the mods on a natural aspirated engine. It is really about refining the result.

My suggestion is to use the bigger TB together with an Open Flash Tablet (OFT). Reason is that the TB will work better with the tune. You won't need to change anything in the tune. For stage 1 , you just need to use the stock air intake.

Is Ecutek better then the unichip setup? Can the dealer see the flash if I use a ecutek? I am looking at the E-force but this won't happen for a couple of years down the road. Thanks for everyone respond. I won't waste money on a throttle body but will loon into budgeting for a catback system now instead.

And for the ones that questioning the result, when Subaru designed this engine the throttle body diameter was expanded from 60mm to 65mm. This is a difference of 5mm. In contrast, intake valve diameter was expanded from 34mm to 35mm and exhaust valve diameter was expanded from 28mm to 29mm. Only 1mm. This is another indication that there were more gains from the throttle body change.

Was this 5mm increase enough? According to Toda Racing it was not and there was the potential of a few more gains with a +2mm increase. In fact Toda Racing provided a larger TB back in 2012 and it was one of their first products for our engines.

The reason I asked about throttle body is because I used to play with mustang back in the 80's & 90's and TB and heads is the first thing we swap out to improve performance and increase HP. This is my first import and highly computer control car so don't know much about tuning.

While this is true many mods you may put on will fail you in Cali.