If you moved the motor back, wouldn't you be able to use those ITBs?

 

I don't own them any more. And they wouldn't work with LS7 heads anyway.

 

No, but that's one of the fringe benefits. I want more room in front of the engine for turbos, oil reservoirs/coolers for LS7 dry sump pans, or properly oriented stock radiators, among other things.

I'm talking about two options for engine position.

Not on my car, we're not. We're talking about custom intake to get the required clearance.

 

This picture shows how nicely you can tuck the engine into the firewall if you don't have the *** end of OEM intake to deal with.

 

Ah, no stock intake, move the motor back and use a sheetmetal intake.

 

Sort of, but yeah, that's the basic idea

 

So, would this custom intake be availible too if we can get our hands on the cradle?

 

At this point, not likely. I'm having trouble enough figuring out how to handle my own, and it's probably going to take a lot of one-off custom work.

I made a deal for "free" labor on a billet aluminum CNC intake with someone in exchange for the Cobra IRS templates and welding jig, and that person has now gone silent and is no longer posting or returning e-mails or PMs, not to mention sitting on a couple pairs of billet sway bar mounts that aren't mine, so it doesn't look like that's likely to pan out. Obviously with CAD/CNC creation, the process, if expensive, could at least be duplicated rather easily to make copies.

I've looked into the Wilson CNC intake, and they don't have one yet that works with L92 intake ports, and it's also too large to fit under the hood with the intricate internal intake runners, and it extends too far to the rear of the block, so if I did go with Wilson, it'd have to be a fresh sheet of paper design, and I'm sure that would be more expensive than the $3,000 or so for a copy of their billet LS7 intake manifold shown below.





So now I'm considering replacing the center section of a GM L92 carb intake (shown below) with a box-style central plenum that doesn't extent past the rear-most intake runner. That would give me the room I need at the back of the intake, but it will also require a lot of custom work and mock-up and won't be readily repeatable.

 

I've been pretty envious of the carb manifolds myself. Small, light, and gobs of power potential. In the case of the ford motor, it would make the whole package shrink by 4-6" in height.

 

Just FYI: The round plastic plug containing the MAP sensor and a large vacuum elbow, sticking out of the back of the intake, is removable. I had to pop out the round plug to inspect a crack and lelocate the MAP sensor on my LS6 intake because it would not clear the fire wall. It is a bit nerve-racking to do, but the plug will pop out with a firm pop from a broom stick end inserted from the intake opening. I found instructions for this on LS1tech.

Relocating the MAP may take care of your clearance problems, and if that doesn't work then you can always remove the vacuum elbow and flaten the plug with some TLC and plastic welding rods and reinsert. Another option is to make a custom plug.

I'm of course assuming that the newer intakes have this plug and is this is the reason for your clearance concerns....

GL

 

I guess the question is, how muh clearance does this cradle require?

Do you also have plans for a transmission mount?

 

Require where? To use the rear engine mounting position?

Yes, eventually.

 

Would relocating the MAP then allow an engine to sit further back like Jim's setup?
Does the FAST have the same MAP/plug design?

 

Not on the LS7 intake. The MAP has been relocated to the front of the intake, but the vacuum stem is in the same relative place as it is on the other LSx intakes. Unfortunately, it's molded as part of the intake and not a gasketed plug like the others have.

 

The MAP sensor itself is really small. It's the vacuum assist that's really in the way of the firewall, and it really doesn't stick out more than an inch or two. If you were to plug that hole you'd have to get creative with some other vacuum source for the brake master, and you still might not create enough clearance to move the motor back. If you look at the picture Jim posted he took a sawzall to the rear of the intake and clipped (right Jim?) the rearmost runner to get it to clear the firewall. My guess is that people wanting to run the motor in the rear position are staring squarely at a custom intake.

 

Refering to what Wanklin was posting, even if you relocate the sensors from the back of the intake, would that still give you the clearnce to mount the stock intake in the rear most position of your cradle. I would assume not with how much "modification" you guys were insisting would be needed to the fire wall.

 

That's pretty hard-core.

I'm assuming that you guys are doing this to get the CG as far back as possible. Perhaps Custom offset motor mount arms would alleviate the need for a custom intake by keeping the weight distribution pretty much the same (since it would still connect to the subframe at the same location) while shifting the engine forward. Ofcource one you go off center you add new variables to the mix, but it should be doable....

Some guy one here did the same with his bolt-on 20B setup.

 

That, and to create room in front of the motor for things like dry sump tanks or exhaust/intercooler piping.


Custom motor mounts don't make extra power.

 

good point

 

Yup.



Yup.

 

Nope, you'd have to lose about 1/2 of cylinder #7's intake runner. I found another picture I took at the same time which better illustrates how much of the intake has been removed.



Not really. It's not like I was planning on using that intake. It was sacrificed to see how much room we had to work with and whether I could keep the #7 cylinder's intake port unobstructed.

 

Did you guys see on ls1tech that the wilson manifold gained no additional power and loss torque on a build LS7 by Katech?

 

Nope. I saw +15 horsepower on a stock LS7 and better breathing at high rpm, indicating that it could help produce more power on the high end, but I hadn't seen results from a built LS7.

 

Here are some links:
http://ls1tech.com/forums/showpost.p...&postcount=142

(links below from the same thread, it also has dyno sheet)
http://ls1tech.com/forums/showpost.p...&postcount=157

http://ls1tech.com/forums/showpost.p...&postcount=167

 

Thanks. Wasn't going to use that intake anyway.