I've been looking at options and wanted to get my ducks in a row.....

Question:

Is the only reason that you have to fab/purchase a new subframe is to make the oil pan clear the steering rack in an FD?

Question:

Would a dry sump setup totally solve this problem including the inlet from the coolers on the front of the motor?


Question:

How many guys are running 20B's with 13B housings due to the larger intake ports on the housings?? Or do most of you guys having all the ports enlarged when getting the motors rebuilt?

I know that I've seen this info on here but I'm unable to find it with a search.......any help and feedback is GREATLY Welcomed and appreciated!

 

Dry sump system (flat bottom abviously) would allow it to fit with no new subframe. 13brew housings are the way to go. Thats what I and several others have. The steel exhaust sleeves in the 20b are directional and there is a limit to how much you can port them that will not let them get as big as the 13brew's. Some people have just replaced the 20b exhaust sleeves with those from a 13brew.

 

I'm in the process of rebuilding my 20B with 13brew housing, simply because the rear 20B housing was already nuked so it made sense to change while I had the engine apart.

As far as the subframe goes you're still going to have a problem with the mounts. The 20B has the mounts on the intermediate plate, while the 13brew has its mounts on the rear plate. You could swap the 20B rear plate out for a 13brew rear plate, but you'd have to port it out to meet the size of the 20B's port. If I remember correctly Dragon was trying to do this a while ago, but ended up making a whole new subframe, which leads me to believe that there was some other reason for ditching the stock subframe.

If you could simply put in a drysump setup and swith out the rear plate (ofcourse, "simply" is a very subjective term, here) then that would be really cool, but I have a hard time believing that its that simple, just because no one and no shop that I'm aware of has done this swap and kept the stock subframe.

 

That is what I'm finding when searching back as far a PFS first couple of setups. I was thinking of drysumping due to the fact that.....if I'm paying that kind of money just to have a motor built #1 I want the best setup that I can get for my moeny...#2 I want to race and participate in as many track days and lapping events and possiably get into some auto-x .....#3 That if I could kill two birds with one stone (not having to purchase/ fabricate a new subframe if I went dry sump) that would help allocate more moeny into other parts of the car.....

But like you state Johnisneglish.......It looks like the motor mounts are in the wrong place anyway.....so I"ll guess I'll have to antie up and get a new subframe and a nice dry sump setup.....

Side Question? (johnisenglish) How did you NUKE your rear housing????

thanks Guys for the Great Information!
Brad Holbrook

 

When I tested the compression on the engine I was getting good (cold) numbers on the front and middle rotor, but nothing on the rear. Looked through the exhaust port and it was missing an apex seal. Upon dissasembly the rotor housing was really badly scratched up, or, nuked, lol.

I already had a 13brew rotor and two housings in really, really good shape, so I just need grab another housing and I'll be set.

I agree entirely with you that it would be great to put the money that would go towards a subframe into a dry sump setup and a ported real plate, but I think that would put the front plate where the steering rack is if used with the stock subframe, regardless of the smaller oil pan. I remember PFS used a dry sump but still moved the engine back several inches, citing their reasoning as being that they would have to relocated the steering rack otherwise.

Honestly, I think it works like this: Steering rack, Motor Mounts (rear plate), Subframe - pick two to change. There's just no way to keep more then one of them intact.

 

Oops, forgot about the mounting points. Didn't mva replace the rear plate with that from a 13brew so it would mount to the stock subframe? Also, they used a modded/ custom oil pan to clear the rack.

 

When I was removing a 13B today from one of my R-1's there is no way in hell that a 3 rotor will fit even if you do the old motor mount (rear housing) trick.....there is only about 2 1/2 inches in front of the 2 rotor and the steering rack.....it has to be moved or you have to recess the motor and cut the fire wall like PFS did in the super car challenge in 2001.....You are absolutely correct Johnisenglish......you have to pick TWO to change....no way around it!!! I hope Howard Coleman finds good data on his bump steering testing.....I really want to keep the stock handling characteristics of my car!

 

Really?

Look closely:



One more for giggles:

 

So what is your secret??? That looks really Really Nice BTW!!!

 

Yes, PLEASE do share about how fitment was for you, Red-Rx7. I can see that you're using a 13B rear rotor housing and I presume rear plate, but how did things for from there?

 

In looking at your website and all the pictures...it apperars that your steering rack is UNDER the motor...which leades me to believe that you lowered the rack?? I'm probably WAY off??? Fill us in!!

 

He has a modded/custom oil pan by mva or am I wrong?

My friend and I will be doing this swap in the next few weeks to his 3rd gen. Dry sump and a different rear plate.
It will fit, just ask Red RX-7. btw, your car is looking great. Nice to see it coming along

 

nice coils

 

I don't know, I'm still skeptical based on when I was taking out my 13B and comparing it in size to my 20B. It just seems to good to be true. Does anyone have any detailed pictures or experiences.

 

the thing with me is that i rather have my engine be held up in the middle then at the rear , i would not feel comfortable with all that weight " hanging " in the front like that ( please , do correct me if there is a front motor support) , especially with such a big turbo ,making huge numbers
maybe its just preferance, but nonetheless , very very nice setup , i lke the turbo , what turbo is it ??

 

Red-Rx7 so how were the larger holes for the large tension
bolts dealt with on that rear housing?
I didn't think that there would be enough there to cut
bigger holes and still have it seal.

matt

 

RED???? Are you going to tell us how you did it????

 

he'll show you but he wants cash, grass , or ***....no body rides for free

 

I guess that after all that drama with MVA and Acosta, Red is keeping all their fitment a secret!! I can't emagine that mounting this engine is that hard anyway....looks like an extra motor mount up front and a 13b rear housing with a dry sump and the stock subframe is good to go! I'll post more information when I get to the next step with my build!

 

Here is an Idea.....Why not just take the Motor mounts that come stock on the 20b and Fab an additional bracket to mate up (Rearward) with the stock subframe. Then you wouldn't need that extra Mount on the front or anywhere else because the motor is being held up in the middle. Dry sump that sucker and ther you go?? Would that work?

 

If you look in the thread that pluto started in the 3rd gen section, there is an excellent pic where it looks like there is enough material in the 20B rear iron to drill and tap for some motor mounts.

One item I have not head discuessed is height of the motor (20B) with 13B motor mounts. The 20B manifolds might not clear the hood. Anyone?

 

I know the secret but if Mike is not saying anything, I shouldn't either. I thought about doing his way but after thinking about it, I thought it would be just as hard (or harder) to make it work and also might risk a chance of changing the characteristic of how the engine perform so I decided to do the subframe instead.

 

come on guys you dont need to be a rocket scientist to see that the lim has been shortened , i am not shure if it will make that much differance in power , since it`s a small piece they cut out , i havent done it so i would know

 

There are motor mount adapters made that will allow one to place a 13B-RE or a 20B into an FD with the stock subframe. The oil pan is another issue, but the mounts are out there. I have a set. Do a search for my name and Cosmo and the images should come up. Steve Kan swears there's no room to use a complete 20B (no 13B rear plate) and not have to move the steering rack. Dry sumping would solve this. If anyone needs sources for the mounts, send me a PM and I'll point you in the right direction.

 

Nah, there's noway to mount the engine and still clear the hood. The entire engine with the manifold is about 3" taller than the 13B-REW setup. The only way to go is to cut the lower intake manifold like what Felix mentioned. That's the trick in making it work with the stock subframe. I didn't want to do that since I *think* it'll move the torque curve way too far to the right making it too peaky. The oil pan isn't anything special, you just have to make a custom oil pick-up tube and (almost flatten the front dip of the oil pan. Clearancing the manifold and water pump filler neck is an issue that isn't easy to do. I'm still having issues clearing the FD water pump assembly on my setup (.25" too high after dropping the subframe by 2.5") but it's not that noticable and really shouldn't matter if I go with a different vented hood. Right now, I'm making custom brackets to mount the radiator and A/C condensor. Sucks not having enough time to work on my car. :-/