I was just wondering if any has seen an aftermarket lower intake to replace the lower manifold of the Cosmo 13B-REW. The low profile nature of this intake looks to be bad for flow.

 

The Xcessive Lower Intake for the 13B-REW FD will bolt on to a 13B-RE Cosmo. You would need to do some port matching, but it is otherwise a bolt-on. The Xcessive Lower Intake has larger runners than the FD manifold, is better balanced (the stock FD intake is very imbalanced) and allows you to run up to 4 secondary injectors. We sell the manifold for $520 plus shipping. You can use your stock fuel rail if you just want to run two secondary injectors and plug the other two fuel ports (plugs included). We also sell a 4 injector top-feed rail for $295.

 

Nice looking piece.

 

When you developed this manifold did you compare some flow numbers of stock FD manifold and yours? Do you have any cfm numbers?

/Lasse

 

You'll have to do a lot more than port matching to fit the upper RE intake to the GZ LIM. The ports on the RE intake are spaced too far out to actually have a good port match. The GZ LIM is lot better than the factory lower RE/REW LIM in both airflow cfm and equal flow between the front and rear ports not to mention having enough 'meat' on it to do some serious porting if the application requires it.

 

yes. this looks like a VERY, VERY robust unit. and the price seems quite reasonable, too. i like it a lot!

 

Well, I physically placed an FD gasket on an -RE motor here in the shop and it was practically perfect. The -RE secondary ports go a little bit lower, but the spacing is the same as far as I could tell. It should only require minor port matching.

 

He's talking about the Re UIM to FD or your own LIM. I have both in my garage, There is no way to fit an RE uim to an FD lim. To get good flow would take at least an inch and a half of spacer.

But them REW UIM's are easy to come by, put the word out that your looking for one on the for sale section you can probably get a TB, UIM and elbow for 100 dollars.

 

What diameter are the runners on the Xcessive Lower Intake? How thick are the walls of the manifold? I want to get a feel for the amount of porting that would be required since the Cosmo primaries are a bigger than the FDs.

Also, what is the dimmension from the engine mounting flange surface to the centerline of the runners. Will it offset the placement if the Throttlebody towards the exhaust?

 

If I want to get better flow I suppose I will have to fill and port the stock Cosmo LIM I have. What is a good epoxy to use? Any tips?

 

D'oh! Yeah, I see what he's talking about now. Sorry for the confusion.

 

If the manifold weren't full height you could sell it with a spacer that people could play with.

Is there a nice flowing short intake with the same basic layout that would be easy to create an adapting spacer for?

 

it would be far easier to buy an REW UIM and TB.

 

It would be even easier to leave it alone. I have no flow data to compare the manifolds so I can't make a decision to change yet. I don't feel comfortable with going to smaller primaries. Especially when the inlet ports are so big. Also, $600 is worth it for me to invest my time instead. For $600 I could probably make a custom manifold.

What is the best flowing EFI manifold around?

 

Blake this wont work, the holes for upper to lower don't match across the two motors or am I misunderstanding you???

-S-

 

My 2 cents; The Cosmo upper and lower manifolds flow better than the FD ones, runners are larger on the Cosmo. Motor will need to be ported to match openings on the Cosmo lower manifold. FD upper manifold will not fit on the Cosmo lower. FD throttle body will not fit on Cosmo upper manifold without a spacer/adapter. Greddy elbow will not fit on Cosmo throttle body. Conclusion: Get the entire Cosmo set up....Like I did

 

Does any make a stubby lower intake for the turbo blocks like the RB delorto lower? Those have 4 runners inline. May need a bit of porting, but the upper connection to my cosmo intake would be a simple piece to make. While I am fabing the connecting adapter I could put in O'ring grooves and eliminate the need for gaskets.

 

Yes, you are right. If you use an FD-style lower manifold, you must use the corresponding FD upper manifold, etc. However, I don't know what the problem with using the entire FD manifold setup is. Theories about which upper manifold flows better do not take into account that the FD upper manifold flows plenty well to begin with; no need for more flow in practice. Ground Zero has made 670+ RWHP on two FDs with our streetported 13B-REW blocks (not -RE Cosmo), with Xcessive lower manifolds and stock FD upper. If you need more flow than that, we need to talk.

The FD lower manifold is a problem mainly for balance and marginally for flow. The upper manifold does not appear to be a problem whatsoever in practice. Cosmo 13B-RE engines do have a lot of high-HP potential with those big runners, but the FD 13B-REW is no slouch either. For FDs, we think it's cheaper and easier to stick to the -REW block unless you are shooting for, say, 700+ rwhp. For FC, the -RE is a nice drop-in, but you don't have to stick with the Cosmo manifolds to get big numbers. Do remember that while the later Cosmo 13B-REs had windowed bearings, the gears are not as hard as the FDs, so you should swap them out if at all possible. The -RE is basically a Series 5 block; the -REW is more advanced and typically has stronger dowel bosses to boot.

 

Would the bigger ports and runners of a Cosmo engine allow the motor to make the same power as the REW with the same port specs but with less boost? Would you need to port it more agressively to do this?