28 replies to this topic

[stick70]

Boost_Junky, on 03 September 2009 - 02:33 PM, said:

Difference is NA vs forced induction.

There are also different characteristics to the intake manifold and head.

this, its hard for me to justify running a 3" throttle body when my 16t only has an outlet of like 2" if that. with blackt5 i could see some possible need for it, but he is also running a 35r iirc

['12brotruckmofo]

laird, on 02 September 2009 - 01:32 PM, said:

The larger TB is a questionable mod. At a minimum, it goofs up your cruise control by causing surges. It is a pain to hook up and you will likely end up with two more hose clamps and some home brew transition. I blew my TB hose off about a dozen times before I finally got a good setup. You will also need to bore out the Intake Manifold to accommodate the larger throttle plate. I used it for a while and took it off with no obvious difference in get up and go. It mostly changes throttle response off idle. That may appeal to you and may feel snappier but I don't think there is any gain in actual flat out acceleration. There is a lot of "I think" and such here so take it for what it is worth. If I could find a bored turbo throttle body, I would probably try that. It would allow use of the factory plumbing which is for me, the biggest drawback to the mod.
Let me know how the cams go though, I have been sitting on a set of NA cams for a while now.

Wasn't a problem for me at all. If you're using OEM pipes though, I can see where you'd run into problems (2.5" to 3" is relatively easy to find). Can't comment on the gains/loss because:
A.) Didn't dyno
B.) Got put on while the motor was being rebuilt...I forgot what the car pulled like, so the butt dyno was off too.

[laird]

the commissar!, on 03 September 2009 - 02:40 PM, said:

Please explain...what in the turbo TB are you boreing?

The opening on a N/A manifold is larger to allow for the larger throttle plate, which swings into the manifold space. if you just stick a N/A TB on a Turbo Manifold, there will be interference.

[the commissar!]

laird, on 03 September 2009 - 06:18 PM, said:

The opening on a N/A manifold is larger to allow for the larger throttle plate, which swings into the manifold space. if you just stick a N/A TB on a Turbo Manifold, there will be interference.

I understand that but you said you were looking for a bored out turbo throttle body...did you mean bored out turbo intake manifold? And if so how are you going to use the factory plumbing since the N/A TB is bigger than the turbo TB?

To work properly you are correct, you have to either run a spacer to allow the plate to swing freely or bore the intake. I have a spacer and bored intake on my setup, which I did at home with a die grinder and polishing wheels etc... Since I have a RIP the piece I need to actually switch over the the N/A TB is the adapter between the RIP tube and the TB.

I keep waiting for Lucky from IPD to tell us they are ready for sale so I don't have to fab one.

[turbodog]

the commissar!, on 04 September 2009 - 12:39 PM, said:

I understand that but you said you were looking for a bored out turbo throttle body...did you mean bored out turbo intake manifold? And if so how are you going to use the factory plumbing since the N/A TB is bigger than the turbo TB?

To work properly you are correct, you have to either run a spacer to allow the plate to swing freely or bore the intake. I have a spacer and bored intake on my setup, which I did at home with a die grinder and polishing wheels etc... Since I have a RIP the piece I need to actually switch over the the N/A TB is the adapter between the RIP tube and the TB.

I keep waiting for Lucky from IPD to tell us they are ready for sale so I don't have to fab one.

Why not use the NA intake manifold and throttle body? that eliminates needing to bore the turbo intake. still need the larger hose to the TB.

[laird]

the commissar!, on 04 September 2009 - 12:39 PM, said:

I understand that but you said you were looking for a bored out turbo throttle body...did you mean bored out turbo intake manifold? And if so how are you going to use the factory plumbing since the N/A TB is bigger than the turbo TB?

To work properly you are correct, you have to either run a spacer to allow the plate to swing freely or bore the intake. I have a spacer and bored intake on my setup, which I did at home with a die grinder and polishing wheels etc... Since I have a RIP the piece I need to actually switch over the the N/A TB is the adapter between the RIP tube and the TB.

I keep waiting for Lucky from IPD to tell us they are ready for sale so I don't have to fab one.

Ok I forgot what I had said. There are or were available, turbo throttle bodies that are bored out and larger plates put in. I think SPG-9 or some such outfit. The advantage over the N/A TB is the plumbing remains as stock.

[O gamias sas]

As I read somewhere here and did to my car the best choice is to put NA intake cam and leave the turbo at the exhaust.Now for the TB the only thing that I can say is that it needs some work to fit and also it has a difference when pressing the acc. pedal to accelerate,it is let's say sharper,but not so great thing.

[dongle]

turbodog, on 04 September 2009 - 09:37 PM, said:

Why not use the NA intake manifold and throttle body? that eliminates needing to bore the turbo intake. still need the larger hose to the TB.

There are little flappy baffle things in the plenum of the N/A.

I'm not sure if it has been attempted but the I believe the consensus is that it would be a bad thing.

[the commissar!]

laird, on 04 September 2009 - 10:56 PM, said:

Ok I forgot what I had said. There are or were available, turbo throttle bodies that are bored out and larger plates put in. I think SPG-9 or some such outfit. The advantage over the N/A TB is the plumbing remains as stock.

Interesting...how much can you bore out a turbo TB?...the one I have (stock from 98 T5) is significantly smaller and there would be not much to gain because there is not much excess material to bore out of the TB. That is why I used a TB from an 850 with the plate from a 960. I actually took pics of the three lined up to compare them but they are on my PC at home. So now I wonder...Is the TB from a LPT bigger than one from a T5?

dongle, on 05 September 2009 - 07:07 PM, said:

There are little flappy baffle things in the plenum of the N/A. I'm not sure if it has been attempted but the I believe the consensus is that it would be a bad thing.

Hmm...sounds like another trip to the junk yard...never noticed that.