Does anyone know how much they bored out?

http://www.350evo.com/catalog/produc...7b99660a54f029

Is there a noticable performance increase?

 

PM me before you buy this.

 

We must both have caught the same itch over the Holidays.

I spoke to the guys at EVO and the bore out is approx. 7-8mm (total) from the mouth of the throttle body then tapers down to zero at the other end. The new throttle plate is approx. 4mm (total) larger and the stake holding the plate is replaced with a low-profile version that is less restrictive to incoming air flow.

Hope that helps.

 

Hmm.. Just wondering how much gain is there by just boring out the mouth, other than boring out the whole thing and port matching the intake manifold.

 

Well, boring out throttle body for an egine that hasn't been radically modified is always a tricky business. Sometimes it could actually do more harm. I would imagine this mod does more good for people with heavy breathing mod such as cams and the ECU reflash to compliment.

I raised the same question to the 350EVO and the response was they tried boring all the way through and saw no gains. They saw more gain doing it this way. I can't confirm nor deny the statement, since I haven't gotten one to play with nor have I even finalized purchasing one. However, using the increased velocity stack approach for throttle body isn't uncommon.

BTW ... I would have gotten one on an impulsive buy ( ) over the holidays if they had it in stock. The throttle bodies are back orderd for a 2-3 weeks. Darn!

 

why don't you wait for the TODA Racing Individual Throttle Body

 

Right Bruce ... and you're going to pay for the bill right?

ITB is more mess than meets the eyes for this car. For one ... it's drive by wire ... making 6 electronic throttle bodies 'safely' linked to the factory ECU is not fun. Most people by that point will have resorted to the more conventional cable driven method. All that money spent only to go backwards ... no thanks :P

 

Thanx for the info Clint. I e-mailed them a few times 3 months ago asking for the same info. Looks like I'll be ordering one soon...too bad the price has gone up.

 

No wonder ... I could of swore the price was lower from my recollection. Darn darn darn! Should of gotten it way back when ... Yes, apparently the demand is quite high for them (from talking to them) and thus the backorder status. It's only too predictable the price was hiked. Boo hoo

 

I did this a few months ago. I bored out the opening of the throttle body, portmatched it to the plenum, polished the inside of the plenum slightly, polished the intake runners in the lower plenum, portmatched that to the intake manifold, and polished the intake manifold.

I didn't remove much material, mostly got rid of casting flaws and smoothed the runners.

Here's a dyno plot. I had to convert the values to Excel, since I didn't have the dyno files. Dynos 1 and 2 were on the same dynojet, dyno 3 was on the dynapak dyno day organized by THX. There are some gains in the high end, just from looking at the difference in the shape of the curve.

Dyno 1 is Z-tube
#2 is Z-tube, Kinetix plenum, UR pulley, popcharger
#3 is Z-tube, Crawford Plenum (kinetix one cracked), UR pulley, popcharger, and the work as described above.

If I'm lucky, I might be able to get another dyno run in this saturday with the 350z's.

 

Did you flash your ECU for the additional air intake?

 

I'm not sure if you're asking me, but no, I haven't. I want to complete all my mods, and then see what's available for ECU management at that point. Currently, I'm leaning towards TS reflash, since I live in Torrance,.

 

The reason they may have just bored out the mouth of the throttle body is to create a venturi effect.