Got my Professional Products single plane intake in today and soon discovered that the adapter plate I was given with my ECM is the wrong size.. so I'm going to have to drill some new holes in the intake- oh well.

Since I have to do this I was wondering about centering the TBI on the intake while I'm drilling and cutting. Should the TBI be centered or is it mounted off-center for a specific reason?
Centering would really work out in my favor, as I have to take a dremel tool to the mouth of the intake so they don't obstruct the flow from the throttle bores and the least amount of material is in the center

Oh, and it looks like my hood's gonna get cut as well



Linked the picture from facebook so let me know if it doesn't show

 

I say center it. If it makes packaging easier, go for it.

 

Does that picture show your problem? I just don't see it, take one from the top.

 

Nope, it doesn't. That shows my hood clearance problem haha

Here is the intake as it sits (pics below) it would be a little easier for me to put it in like this, now that I think of it- much less drilling but a little more dremel-ing.

But of course, I'm not looking for the easy way out. I want it to perform the best it can and if centering is needed for that, then I will do it

 

Those adapters don't look so bad on a dual plane intake but sure looks wrong/dumb on that intake! You could get the right adapter? Also save 1/4 inch by using a 1/4 inch transdapt steel instead of aluminum. Be careful to seal it up good and use studs lock tighted in or short bolts that don't go through adapter and hit intake causing a HUGE vacuum leak, before you install it.

For clearance the caprice TBI air filter was the lowest I have seen for TBI.

 

I think you're right Mark. I really don't want to blow $50 on a simple plate but in the process of modifying my current plate I'll probably spend time working on it that could be spent landscaping and making the money to buy a better product.

Not to mention, the 1/4" lower height will help with the already f***ed up throttle linkage geometry

 

I think they are only $35, you could recover that from the one you have...

But the 1/4 plate steel are no where near as true! Use O2 safe gasket sealer both sides to intake and try to get away with none to TBI, or thin layer both sides as well, let it dry overnight. Pay special attention to studs or bolts not protruding through adapter and causing vacuum leak! Not to mention gouging aluminum intake!!!

 

Nope, They're around $44. And you're right, I might be able to get $30 or so from the one I have now.
As per the gasket sealer, I have some Ultra Copper RTV I bought for my head gaskets- that should do the job.

 

No that is the wrong type sealer, for a much differant purpose.

 

You are correct. I'll pick up some sealer this week then

 

I like the black RTV. it seems to set up harder but still rubber, not solid. O2 sensor safe should be on the package.

HTH!

 

Well whatdya know, I have a tube of black RTV in the basement. Definitely saves me a trip and a few bucks

 

The offset is to better direct the air flow into plenum of intake. At part throttle the angle of blades direct the incoming air to rear of plenum.

 

I understand that but the offset is oriented towards the rear, enhancing that effect and starving the front cylinders

 

Decided not to buy another one and just drilled my current adapter and intake manifold. Pictures will be up in my build thread soon.
My question now is, do I need to buy a gasket for both the adapter to the intake and TBI to the adapter, or can I just use the black RTV to seal everything up?

 

I'd use gaskets, rtv doesn't hold up to gas very well.

 

Yes use gaskets! I looked on the black RTV I have here and it says not to come in contact with gas! So it must have been differant gasket sealer I used on them as they ran for years with no issues.

If everything is fairly true, gaskets alone should do the job, but I have had so many vacuum leaks with those metal adapters.

Since your back to a straight true aluminum adapter probably no need for gasket sealer. I have never had issues with those.

 

Yup, I was wondering about that, as I saw that notice too.
That all being considered, I'll try to pick up some new gaskets today so I can start finishing the intake assembly. The last step will be fitting the IAT sensor to the intake manifold

 

IAT goes in air cleaner. MAT goes in intake manifold. They are handled toatally differantly in ECM... what was the ECM designed for?

The sensors themselves read the same temp, same as a CTS. But the way the ECM uses the temp is differant.

 

I would put the IAT in the air cleaner but due to the air-gap style of the intake manifold, the readings would be off. I read a thread a few weeks ago on putting the IAT in the intake for a more accurate reading but can't seem to find it. I believe dimented24x7 wrote it, but I could be wrong
The ECM will be able to handle it just fine, as I'm running EBL Flash

 

Why?

IAT reads the temp of air coming into the intake.

MAT reads temp of air in intake which is differant because the fuel coming from TBI is evaporating, and on other manifolds the intake itself is heated by exhaust crossover and coolant passages.

What it boils down to is the way the ECM is designed to use the temps it gets for calculating fuel.

Since you have EBL just ask RBob what the setting in EBL should be for the way you have the sensor mounted.

 

Found it: https://www.thirdgen.org/forums/tbi/407850-had-ae.html

Hopefully I can make mine work without having to convert to MAF...

 

No reason to need MAF, just that IAT and MAT are 2 differant temps and the way the ECM uses those temps has to be right. You can change a MAT to IAT or IAT to MAT but ECM needs correct info.

Just ask RBob and he will show you what needs to be done with EBL.

 

TBI cars don't have MAT, just IAT and CTS. I'll see how it runs with my current setup and programming before I bug him. Who knows, I could get lucky and not have any problems