Shortening Of The Lim
10-01-2003, 03:16 PM
#1
Senior Member
Thread Starter
Join Date: Jun 2003
Posts: 161
I'm trying to install a 20b into my FD by pushing the back of the engine about 7 inches back into the transmission tunnel. This way, the front of the engine is at the same place where the 13b was. The problem is the UIM will hit the firewall. So I'm thinking about shortening the top of the LIM by about 2 inches. How will it effect the characteristics of the engine? I'm guessing it'll reduce torque output at lower RPM......anything else?
An Tran
An Tran
10-02-2003, 02:51 AM
#4
Senior Member
Join Date: Feb 2003
Location: Iowa Baby....Oh-Yea
Posts: 212
pushing the back of the engine about 7 inches back into the transmission tunnel
So you plan on making a new PPF? I think it would be easier to modiy the subframe. I know there is the distribution issue but does anyone actually have weights from a 4-point scale? Battery relocation and A/C removal should cancel out the added weight of the extra rotor.
10-02-2003, 06:54 AM
#5
Senior Member
Thread Starter
Join Date: Jun 2003
Posts: 161
I'm going to shorten the PPF and drive shaft by the same amount (~7 inches).
I will fabricate a new subframe from scratch......this should be challenge.
I will move the transmission shifter forward about 6 inches, into the access plate just infront of the current shifter location.
The reason I want to push it all back is because of weight distribution, and I don't want to move the steering mechanism.
In shortening the LIM, I would have to establish threaded holes for the fuel rail. The injectors need to be pushed down into the holes with enough force (to compress the o-ring) so that fuel doesn't leak. This might be difficult to do.
As for the loss in torque, if I install a 2 inch spacer between the TB and the UIM, will it make up for the shortened LIM?
An Tran
I will fabricate a new subframe from scratch......this should be challenge.
I will move the transmission shifter forward about 6 inches, into the access plate just infront of the current shifter location.
The reason I want to push it all back is because of weight distribution, and I don't want to move the steering mechanism.
In shortening the LIM, I would have to establish threaded holes for the fuel rail. The injectors need to be pushed down into the holes with enough force (to compress the o-ring) so that fuel doesn't leak. This might be difficult to do.
As for the loss in torque, if I install a 2 inch spacer between the TB and the UIM, will it make up for the shortened LIM?
An Tran
10-02-2003, 12:36 PM
#6
Junior Member
Join Date: Oct 2003
Location: U.K.
Posts: 17
I'm in the midst of the samejob; front cover will end up in same place as 13B's in order to keep weight distribution as good as poss; the intermediate plate and extra rotor housing weigh quite a bit and the idea of it hanging out in front of the wheels doesnt excite me 
We're using a 'hybrid' FD subframe with interesting sump mods etc...no moving of rack or owt.
We've shortened the PPF already and will do the exact same thing as you mention with the shifter to bring it back to roughly the stock location.
Got the same inlet manifold issues at the moment...still unsure as to what to do 
Thinking a totally custom item may be less hassle in the long run...
Still, should have exhaust manifold finished soon-ish - then we can mount the turbo and see what rooms left for every thing else - at least it will look a little more 'finished' then
Let us know what you decide and the results.
Good luck,
R.
We've shortened the PPF already and will do the exact same thing as you mention with the shifter to bring it back to roughly the stock location.
Got the same inlet manifold issues at the moment...still unsure as to what to do
Thinking a totally custom item may be less hassle in the long run...Still, should have exhaust manifold finished soon-ish - then we can mount the turbo and see what rooms left for every thing else - at least it will look a little more 'finished' then
Let us know what you decide and the results.
Good luck,
R.
10-02-2003, 01:35 PM
#7
Senior Member
Join Date: Mar 2003
Location: Sunny South Florida :)
Posts: 1,963
each engine series progression gsl-se 13b, s4, s5, s6. The intake runners have gotten longer and longer, I believe the reason for this is to optimize the the torque / free flowing balance.
Probably increase your hp a bit, but the torque will suffer. But hell it's a 20b you'll have plenty of both!! If it were me, I'd leave it how it was meant to be tho.
Probably increase your hp a bit, but the torque will suffer. But hell it's a 20b you'll have plenty of both!! If it were me, I'd leave it how it was meant to be tho.
10-02-2003, 03:20 PM
#8
Senior Member
Thread Starter
Join Date: Jun 2003
Posts: 161
We're using a 'hybrid' FD subframe with interesting sump mods etc...no moving of rack or owt.
I'm going to use an FD oil pickup, so I'll have to make a new oil pan, one that is only 3 inches deep. OR, I can shorten the 20b oil pickup by an inch, and bring up the bottom of the stock 20b oil pan by an inch also.
10-03-2003, 07:41 AM
#10
Senior Member
Thread Starter
Join Date: Jun 2003
Posts: 161
Ok, I studied this situation long and hard last night. One of the constraints I pose is that the bottom of the oil pan must be 5 inches off the ground. With that said, here are my options:
1. Currently, the engine is pushed back 3 inches (in lieu of 7). This leaves the front rotor directly above the front wheel's centerline. No mods to the UIM, LIM, or transmission shifter is needed. Steering rack needs to be moved, and ABS lines and the lip under the ABS deleted, however. This is a compromise in weight distribution.
2. Use a dry sump system (1 inch thick oil pan) and shorten the LIM by 2 inches. The engine still won't sit low enough to push back 7 inches....more like 5 inches.
3. Breach the firewall. This will truely benefits weight distribution, and take full advantage of moving the shifter.
Right now I'm thinking option 3. I want my car to handle well. Not just straight line performance.
An
1. Currently, the engine is pushed back 3 inches (in lieu of 7). This leaves the front rotor directly above the front wheel's centerline. No mods to the UIM, LIM, or transmission shifter is needed. Steering rack needs to be moved, and ABS lines and the lip under the ABS deleted, however. This is a compromise in weight distribution.
2. Use a dry sump system (1 inch thick oil pan) and shorten the LIM by 2 inches. The engine still won't sit low enough to push back 7 inches....more like 5 inches.
3. Breach the firewall. This will truely benefits weight distribution, and take full advantage of moving the shifter.
Right now I'm thinking option 3. I want my car to handle well. Not just straight line performance.
An