4" intake requires plenum spacer??

[Brandon706]

I just converted to a SD tune, so Im interested in using a RJC 4" intake. I am concerned about clearance between the 3" up pipe. Will I need a plenum spacer? If so will a 1" spacer clear with the vacuum block deleted? thanks

 

[marleyskater420]

One of the larger issues is the IAC fitting, even with the 45degree adapter, if you have 3" intercooler pipes. which it sounds like you do.

If people run the 1" spacers without issue, I wouldn't see there being a problem with the spacer, especially if you deleted the vacuum block.

I would be more concerned about the clearance of the piping around the turbo inlet and IAC.

 

[dank GN]

I run a spacer and have a 4” intake pipe

 

[Brandon706]

I run a spacer and have a 4” intake pipe View attachment 331790View attachment 331791View attachment 331792

Do you have any issue wearing the head liner?

 

[SPOOLFOOL2]

I run the 4" Big Mouth air intake. Had to "dimple" the bottom of my up pipe about a quarter of an inch to make it work.
No spacer and still have the vac block. Not sure if this helps.

 

[TurboTnZ06]

I used a 4 inch intake tube, 3 inch up-pipe, no spacer, but I used a 70mm plenum and accufab TB. I'd recommend denting the bottom of the pipe so it doesn't push the radiator hose into the belt. I now run a 1 inch spacer (for vac lines etc) and I stuck a 6 inch K&N right on the turbo for now, no inlet pipe at all- it actually clears the rad hose just fine.

 

[captndave737]

I have a 4" intake and 3" up pipe, angled IAC, no plenum spacer and it fits fine.

 

[1986 Buick GX1]

I used a 4 inch intake tube, 3 inch up-pipe, no spacer, but I used a 70mm plenum and accufab TB. I'd recommend denting the bottom of the pipe so it doesn't push the radiator hose into the belt. I now run a 1 inch spacer (for vac lines etc) and I stuck a 6 inch K&N right on the turbo for now, no inlet pipe at all- it actually clears the rad hose just fine. View attachment 331805

View attachment 331804

One thing to remember is the accufab / Kenne Bell plenums are stock height, where as the Precision plenum is 5/8" taller than stock.

I don't know about the Hemcos or others, but something to keep in mind.

I have the Precision plenum w/ RJC's power plate and my vac block was into the hood liner (before I modded the vac block), but I have the stock motor mounts and stock body bushings at the moment.

 

[JEvans22]

Do you have any issue wearing the head liner?

When I ran the inch spacer and a vacuum block it did wear a groove into my mint headliner. New factory passenger engine mount and H&R driver mount.

 

[Hotfoot]

Mine is a cotton front mount with 3” up pipe and a hemco plenum no spacer with 4” fresh air, space is fine my up pipe rubs on the hood liner so I replaced it with an aluminum HOODSKIN and now it just touches with H&R motor mount

 

[Brandon706]

When I ran the inch spacer and a vacuum block it did wear a groove into my mint headliner. New factory passenger engine mount and H&R driver mount.

i know with GN1 plenum and 3” Rjc up pipes there is barely any room for my old 3.5 intake. I wouldnt mind using a 1” spaced so I can delete the vacuum block. U think if u had that vacuum block deleted u could use your original headliner?

 

[JEvans22]

i know with GN1 plenum and 3” Rjc up pipes there is barely any room for my old 3.5 intake. I wouldnt mind using a 1” spaced so I can delete the vacuum block. U think if u had that vacuum block deleted u could use your original headliner?

Yes I believe with the vacuum delete plate it would have cleared the hood pad and wouldn’t have been an issue.

 

[RUQWKNF]

I used a 4 inch intake tube, 3 inch up-pipe, no spacer, but I used a 70mm plenum and accufab TB. I'd recommend denting the bottom of the pipe so it doesn't push the radiator hose into the belt. I now run a 1 inch spacer (for vac lines etc) and I stuck a 6 inch K&N right on the turbo for now, no inlet pipe at all- it actually clears the rad hose just fine. View attachment 331805

View attachment 331804

Keep an eye on that filter for signs of deformation and twisting. Having it installed so close to the turbo will cause the walls of the filter to become somewhat pliable under repeated use. That was something we were instructed to inform customers all the time, as a lot of turbo failures came from filters collapsing and pieces of the filter mesh getting sucked into the compressor and taking out the compressor wheel. Saw it with both K&N and S&B filters when customers mounted them directly to the compressor cover like this.
Just looking out for you.

-Patrick-

 

[captndave737]

My up pipe does rub on the hood liner. No spacer here.