- 2,609
- 35
- Dec 17, 2004
-
East Hampton,
Connecticut
Well, I've been busy trying to get this set-up on a dyno (did a 42mm set-up earlier and didn't like the power for drag racing - probably should do a post on that as well) and finally got her on there and thought you guys might be interested.
I did this work with my Buddy Stevie at his machine shop using his expertise in making parts;
We first cut up 4 stocker Eclipse TB's and straight bored them to 52mm;
We then made adapter plates for each TB to transfer the 52mm TB from the 42mm holes that I had with the other TB's. We then bored that out for a smooth transfer and drilled appropriate holes for mounting (no pics of any of that. Just forgot at the time,
)
We decided to spin the TB's so that they use one axis (I still don't think this is the easiest/quickest/best way. But its the direction we chose);
You can see the 3/8 rod we used to line them up (fits perfectly through the TB's). It was a bit of a chore to get them straight since I originally just eyeballed the straight line of the 42mm TB's before we welded the original adapters on. But they were really close anyway.
We then took two throttle boddy shafts and welded them together (welded TB 1 with TB 2 and welded TB 3 with TB 4). Leaving TB 2 and 3 a seperate removable joint for adjustment and ease of removal etc. In this over head pic you can see the rods going all the way through;
and here is a pic of the joint;
You can see we retained the stock throttle stop (but none of the plastic) so that I can have a place for the back two TB's to stop. Instead of just allowing them to twist off the one stop in front (just a little support). We welded a "barrel" on the end of the stop and that fit into the throttle body next to it (the break point between the two sets of throttle bodies).
and here's a pic of them at WOT;
Welding the rod was fun, in that, when you welded the rod (with the butterfly's in place), the heat expanded everything, so the twisting action of the throttle movement, bound up and made us panic a bit about the welding ####ing our whole set-up,. But when she cooled, it was back to functioning properly.
Got a little more work to do. From this point, I already polished out the bore and took her apart to RTV the plate on. Just working on spinning the velocity stacks now (decided we couldn't find any for a reasonable price, so Stevie said, "#### it, we'll make some". I need to fit them on and set-up some kind of throttle cable. We retained the stock throttle arm set-up;
but it obviously has a different direction to deal with.
As for the TPS, we also retained the stock tongue;
My buddy spun these velocity stacks out on his machine;
30mm tall. 52mm opening at the TB with a 6 degree angle from the opening.
So I put these on with good ole JB Weld and diesel hose to hold them in place;
(but that didn't hold so I ended up using clamps on the diesel hose).
Now for the good stuff;
I want to post up the dyno for the 42mm ITB's I did prior so you can make a comaprison to the 52mm's;
and here are the 52's;
and now a comparison between the 52mm ITB's and a dyno for the 65mm Mustang TB (with AMM plenum) that currently holds the most power record for na's with 219.4whp (incidentally, these were all done on the same dyno; a Dyno Dynamics dyno by Matt at dentSport in Norwood Mass) :
You can see the drop off's with torque and power in the low range with the 52mm ITB's. By the same token, you can see the extensions in power and torque (as well as the shift in peak power) with the 52mm ITB's
I don't believe that firewall space is an issue, got more than enough room. Cowl induction with a box MAY help at speed, but not sure. My current suspicion is either the ITB's are too small (doubtful) or we have a resonance conflict.
As for torque; the torque numbers fell back to, basically, the same as the 65mm single throttle body. I still like the 42mm ITB's for the street.
Geez it took a long time and lots of effort to get to.....um, pretty much nowhere,. But I do have a vid of the 52mm ITB's running;
‪Eclipse 420a 52mm ITB's, Crower 3's, 12.5 comp, LTH, MSnS‬‏ - YouTube
MB
I did this work with my Buddy Stevie at his machine shop using his expertise in making parts;
We first cut up 4 stocker Eclipse TB's and straight bored them to 52mm;
You must be logged in to view this image or video.
You must be logged in to view this image or video.
We then made adapter plates for each TB to transfer the 52mm TB from the 42mm holes that I had with the other TB's. We then bored that out for a smooth transfer and drilled appropriate holes for mounting (no pics of any of that. Just forgot at the time,
)We decided to spin the TB's so that they use one axis (I still don't think this is the easiest/quickest/best way. But its the direction we chose);
You must be logged in to view this image or video.
You can see the 3/8 rod we used to line them up (fits perfectly through the TB's). It was a bit of a chore to get them straight since I originally just eyeballed the straight line of the 42mm TB's before we welded the original adapters on. But they were really close anyway.
We then took two throttle boddy shafts and welded them together (welded TB 1 with TB 2 and welded TB 3 with TB 4). Leaving TB 2 and 3 a seperate removable joint for adjustment and ease of removal etc. In this over head pic you can see the rods going all the way through;
You must be logged in to view this image or video.
and here is a pic of the joint;
You must be logged in to view this image or video.
You can see we retained the stock throttle stop (but none of the plastic) so that I can have a place for the back two TB's to stop. Instead of just allowing them to twist off the one stop in front (just a little support). We welded a "barrel" on the end of the stop and that fit into the throttle body next to it (the break point between the two sets of throttle bodies).
and here's a pic of them at WOT;
You must be logged in to view this image or video.
Welding the rod was fun, in that, when you welded the rod (with the butterfly's in place), the heat expanded everything, so the twisting action of the throttle movement, bound up and made us panic a bit about the welding ####ing our whole set-up,
. But when she cooled, it was back to functioning properly.Got a little more work to do. From this point, I already polished out the bore and took her apart to RTV the plate on. Just working on spinning the velocity stacks now (decided we couldn't find any for a reasonable price, so Stevie said, "#### it, we'll make some". I need to fit them on and set-up some kind of throttle cable. We retained the stock throttle arm set-up;
You must be logged in to view this image or video.
but it obviously has a different direction to deal with.
As for the TPS, we also retained the stock tongue;
You must be logged in to view this image or video.
My buddy spun these velocity stacks out on his machine;
You must be logged in to view this image or video.
30mm tall. 52mm opening at the TB with a 6 degree angle from the opening.
So I put these on with good ole JB Weld and diesel hose to hold them in place;
You must be logged in to view this image or video.
(but that didn't hold so I ended up using clamps on the diesel hose).
Now for the good stuff;
I want to post up the dyno for the 42mm ITB's I did prior so you can make a comaprison to the 52mm's;
You must be logged in to view this image or video.
and here are the 52's;
You must be logged in to view this image or video.
and now a comparison between the 52mm ITB's and a dyno for the 65mm Mustang TB (with AMM plenum) that currently holds the most power record for na's with 219.4whp (incidentally, these were all done on the same dyno; a Dyno Dynamics dyno by Matt at dentSport in Norwood Mass) :
You must be logged in to view this image or video.
You can see the drop off's with torque and power in the low range with the 52mm ITB's. By the same token, you can see the extensions in power and torque (as well as the shift in peak power) with the 52mm ITB's
I don't believe that firewall space is an issue, got more than enough room. Cowl induction with a box MAY help at speed, but not sure. My current suspicion is either the ITB's are too small (doubtful) or we have a resonance conflict.
As for torque; the torque numbers fell back to, basically, the same as the 65mm single throttle body. I still like the 42mm ITB's for the street.
Geez it took a long time and lots of effort to get to.....um, pretty much nowhere,
. But I do have a vid of the 52mm ITB's running;‪Eclipse 420a 52mm ITB's, Crower 3's, 12.5 comp, LTH, MSnS‬‏ - YouTube
MB
