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RIPPerized
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I installed the Diamante intake manifold with the SDS. I placed some pics in my garage. One shows the rear of the manifold with what I did for the vacuum lines. I tapped the plenum in two spots with the same 1/8" NPT tap that I used on the casting that the oil filter attached to.

Originally, I tied all of my additional vacuum lines to the brake booster line. I noticed my brakes felt funny and the vacuum was 16 inHg at a warm idle. I added two more attachment points and my vacuum increased to 18 inHg.

Notice the C-shaped metal tab holding the hoses in place. The front bank O2 sensor connectors used to be attached to it. It was no longer used when the SDS went in. I had to devise something to keep the throttle cable from rubbing on the hoses.

The longest two bolts that attach the manifold to the lower intake (center two in back row) were now 3/8" too long. I used 1/2" copper pipe cut to 3/8" long as spacers, instead of buying new bolts. BTW, don't mix these up with the spacers for the fuel rail when putting in the SDS fuel injectors, as they are 5/16" long.

The bracket that the original manifold attached to, in the back near the throttle body, was removed and the top 3-4" was cut off. Note that the two pipes fastened to the bracket contain antifreeze. Removing the bracket before disconnecting the pipes will result in a sticky mess, and smokes like crazy when the car is started. For this reason the bracket must be cut down and reinstalled. There is no longer a means to support the new manifold in the rear, try not to support yourself by putting your hand on the manifold.

Using the stock throttle body was easier than trying to work with the Diamante one. Offhand, I can't remember why I didn't want to use it.

Also, the battery can be kept in the engine bay if it is replaced with a smaller one. I used an Optima Yellow Top D51. The fuse at the positive terminal was replaced with a 100 Amp in-line fuse when the stereo went in. This is not required to be done.

The battery tray needed to move 1/4" away from the engine. To do this the 4 mounting holes needed to be elongated using a die grinder or Dremel tool. The combination of moving the tray and the Optima battery puts the negative post very close to the strut tower bar. There are two options, first is to fabricate your own battery hold down, second is to use an aftermarket post terminal with a plastic cover. This is to prevent arcing between the negative post and the strut tower bar.

The wires for the sensor on top of the plenum were extended by 6".

Also, there is a hose that connects the bottom drivers side of the throttle body to the coolant system. This needs to be replaced with a 3-4" longer one. The original one will connect, but will kink the hose.

All in all, very easy to swap. The only advantage I see to the GTS intake is that the last two things mentioned may not need to be done.

I think that's everything. Feel free to add.
 

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SPYDEY MF!
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what does adding the Diamante intake plenum do for the SDS? Does it improve flow or performance or anything? Or is this plenum safer to run with the SDS? I am confused by this. I have seen quite a few people running the SDS with the Diamante Intake Plenum and I never really understood it. If you could explain it to me, that would be great. Other than that, congrats on the swap.
 

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The 3G GT employs an intake manifold plenum that has unequal runners to the cylinders. The Diamante manifold in reference and the 3G GTS manifolds use plenums that have equal length runners to all cylinders. Generally speaking, with equal length runners to the cylinders, each cylinder should receive the same amount of air. With unequal length, some cylinders will receive more air, some will receive less. This disparity along with the inability of the ECU to tune each cylinder by airflow, causes a headache for tuning when forced induction is involved. When dealing with a greater volume of air and fuel, tuning and obtaining consistent air-fuel ratios across all cylinders becomes ever more important due to the likelihood of greater heat due to the increased volume.
 

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SPYDEY MF!
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thank you Edlo for that explanation. So is there a differenece between the Diamante intake plenum and the GTS intake plenum? See, I have a 2003 spyder GT which has the GTS intake plenum. So is there any known differencese between the two or are the Diamante ones easier to get ahold of?
 

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ARACHNO said:
So is there a differenece between the Diamante intake plenum and the GTS intake plenum? See, I have a 2003 spyder GT which has the GTS intake plenum. So is there any known differencese between the two or are the Diamante ones easier to get ahold of?
Performance differences, I'm not sure which is better flowing as far as the two mentioned. The GTS has a valve that, when controlled by vaccuum(I think), will alter the path of incoming air to one of two sets of runners. Not sure if anyone got the valving to work on a non-GTS Eclipse though. It's a rumor that the GTS plenums are tougher to get... and it seems reasonable.


Diamante Plenum


GTS Plenum


GT Plenum
 

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SPYDEY MF!
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yes they do tear.



I have had the car since May and I just found this out in November, lol. I found out when converting my cai to short ram and then looking at the Intake Plenum. I am not complaining thought, it breathes a little better and adds a few horses.
 

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Mr. Clean said:
The combination of moving the tray and the Optima battery puts the negative post very close to the strut tower bar. There are two options, first is to fabricate your own battery hold down, second is to use an aftermarket post terminal with a plastic cover. This is to prevent arcing between the negative post and the strut tower bar.
Umm... The negative terminal is already connected to the chassis of the car. There will be no arc. Good write-up though. :yesway:
 

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Malveaux said:
Umm... The negative terminal is already connected to the chassis of the car. There will be no arc. Good write-up though. :yesway:
ya but be careful with the ratchet while working with the postive terminal :sweat:
 

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Malveaux said:
Sounds like you speak from experience? I don't think I want to see that happen. LOL
ive seen a few sparks fly. nothing major. a wrench got dropped across my cars terminals and melted a lil off of one. :ugh:
 

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Chase2000gt said:
:agreed: i did the same thing yesterday :sweat:
it happens soo fast, and the battery is such a convenent place to put tools!

i also burnt my fingers picking it up :doh:
 

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Discussion Starter #19
Malveaux said:
Umm... The negative terminal is already connected to the chassis of the car. There will be no arc. Good write-up though. :yesway:
Oh, but there is arcing. When the ground wires are disconnected from the negative terminal, the power wires are connected to the positive terminal, and the negative terminal gets too close to the strut tower brace. The D51A Optima Yellow Top battery is taller than the stock battery. BTW, if you get the D51B battery, the posts are reversed, so you run the risk of shorting the positive terminal to the strut tower brace.
 

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With the VRX can you still have the battery up front ? I prefer to no relocate the battery so I went with the GTS plenum. Also at the time I had an extra battery in the trunk for the audio system which is no longer there.

 
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