Marcel Burkett

I am aware (after searching) of the majour differences between these engines , question is , is the better cosmo better suited for high hp with all things equal , ie porting , turbo etc. Everyone is making a big deal about the intake ports , runners and throttle body , but does this make any appreciable difference at the dyno and at the track , would it be worth it to look for and purchace one (a cosmo) instead of sticking with the REW ? . If I am building a COSMO based engine I would be swapping in all the "better " FD parts , totally eliminating the exhaust sleeves and porting the hell out of it (both intake and exhaust ports ) and also adding a semi pp , what ya think ?.

astrochild7

iTrader: (3)

yes semi pports are you doing them yourself.. i'd like to discuss port timing with you i just marked mine with drykem. I'm going for the scoot style, a little high. and are you running boost. are you modding the mani. or going custom..

jody hammock

fatboy7

The longer cosmo intake runners and smaller plenum volume should make more low end than the REW. With the right porting I'd expect a pretty nice powerband, and better turbo spooling characteristics.

Marcel Burkett

But is it worth the extra effort , that being different mountings , some spacer of some type on the intake and locating one due to the lack of availability .

DoubleRX

i thought RE can mount directly???

CrackHeadMel

iTrader: (2)

nope, it needs special mounts

rx7tt95

The FD has mounting points on the bottom rear plate whereas the Cosmo mounts on the housing sides. You can get Cosmo to FD mounts at Compact Car Performance in Naples, Florida. PM me for the number, not sure if I'm allowed to post it and I don't have much desire to get banned. They used my car to fab them. Still breaking in the engine so I can't comment on engine characteristics. I'm also using the FD upper/lower intake manifold and not the Cosmo. Didn't have the time or desire to mess around with spacing the FD's throttle body out. You'll need a Cosmo-specific secondary fuel rail, top feed injectors and FPR. K2RD sells the rails. Here's a pic of the mounts installed. They use two mounting points on either side and the stock FD lower portion. Made out of iron and seem to be holding up just fine.

rx7tt95

double post...trying to post a pic and not working too well.

SomeGuy_sg

damn ...would really love to see some pics.

SomeGuy_sg

will putting in a 13B RE have any bumpsteer?

rx7tt95

http://www.nopistons.com/forums/inde...howtopic=14153

Go there for pics. No, won't cause any bump steer. Sits in the same location and is the same dimensionally as the stock third gen REW motor. Now a Cosmo 20B, if mounted Pettit style (rear of the motor sits in same place as stock engine) the extra length requires that the steering rack be moved down/forward. But you'l have no such issues with the 13B RE 2 rotor cosmo motor.

SomeGuy_sg

The 13B RE and the 20B REW were both used in the Cosmo. Are their stock power output the same ? What about torque ? are the larger intake ports and size the only favourable points of the 13B RE?

rx7tt95

No, hp/torque is not the same between the two. The primary/secondary ports/runners are identical on both engines however, albeit the 20B has an extra housing and center plate :-). Yes, other than the larger port runner castings, there's no real advantage although some say the intake manifold, with it's larger runners and plenium chamber produces more torque sooner than an FD pulse charge type intake. I didn't test it out however, but I may do so in the future. You really have to hog out (carefully) the FD's lower intake manifold to match it to the Cosmo ports.

Marcel Burkett

Has anyone tried drilling out and tapping holes to allow attaching the motor mounts to the rear plate ( like the FD's ) , is this even possible ? .

Marcel Burkett

^

rx7tt95

I have heard that there are two different variations of the RE engine, at least two different castings for the rear plate. One has enough material to do that and the other (the version I think I have) which doesn't. Dunno what would happen to the water jacket though....why not just use the same mounts I have? I can facilitate for you if need be.

kyle@insight

What exactly are your goals for the car? I think that would help in deciding what if it would be worth it.

12abridgeport

Ok, what's a semi pp?? How is that possible?

AJC13B

In a perfect world, it seems the cosmo upper manifold mated with the FD manifold will work the best.

My cosmo engine, a friends and someone else on this board all experienced the same things. On dyno runs, the peak power is made around 7000rpm, no higher. Tuning changes or more boost makes no difference.

Don't get me wrong, the engines make power It just makes it early...

rx7tt95

Cosmo upper and FD lower? They don't line up very well (sarcasm) and would require a bit of drilling and modifications, no?

What sort of porting was done on each of the Cosmo engines? Nothing wrong with good power early however.

AJC13B

It would require a bit of work, but from what others have said it would work the best if you wanted to keep it stock looking under the hood!

Not sure on the other 2 engines, but mine had fairly stock inlet ports and heavily ported exhausts.

True, there is nothing wrong with good power early

AJC13B

It would require a bit of work, but from what others have said it would work the best if you wanted to keep it stock looking under the hood!

Not sure on the other 2 engines, but mine had fairly stock inlet ports and heavily ported exhausts.

True, there is nothing wrong with good power early

rx7tt95

I know there was someone who mentioned an adapter plate that mates the Cosmo upper to the FD lower. I'm sure it was a company out of Japan. Dragon would probably know :-)

I'm willing to bet that if you ported the secondaries out that power would be moved up in the powerband. The LIM might be the limiting factor. We'll see what I come up with when I get on the dyno.

88fc3sw/HX83

Guys, why not just port-out the 13BRE LIM, that way there would be NO adapting issues?

rx7tt95

That's what I've done, but primarily just at the bottom to mate to the larger runners on the Cosmo plates. It'd be pretty hard to get all the way down however and you'd probably have to extrude hone it to port the full length of the runner then port match the ends by hand.