Need suggestions, repairing S13 firewall/trans tunnel - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

tb13 · 03-31-2019, 09:22 AM

I picked up an S13 from a friend of mine this weekend that was heavily modified to run an RB with custom mounts behind the front crossmember. This required a significant amount of the firewall to be cut out along with the trans tunnel to be hacked up. I have no interest in attempting to run a setup similar to that was intended, I am just looking to put a firewall/ trans tunnel back in the car.

How would you guys go about replacing what is missing? Chop an entire firewall/trans tunnel out of a donor car or just replace what is missing? Really want to get the car back in one piece and make something of it, let me know what you guys think!

afishysilvia · 03-31-2019, 09:56 AM

Drill spot welds out of donor car and swap in entire section would be correct way.

tb13 · 03-31-2019, 10:47 AM

Quote:

Originally Posted by afishysilvia

Drill spot welds out of donor car and swap in entire section would be correct way.

That will work for the firewall and was the way I was leaning, but wanted to ask.

As far as the trans tunnel is concerned, that is part of the floor board which I can't replace due to the car having a cage. Cutting the same section from the donor car, slightly larger, then trimming to match the missing section should be the best method, right? Will tacking it back into place be sufficient or should it be fully welded into place?

afishysilvia · 03-31-2019, 11:57 AM

Factory was spot welded and then body seamed. I was planning to just weld mine in completely then using sealer. I think that would be sufficient.

jedi03 · 04-01-2019, 09:36 AM

my uncle does that with his race cars and bolts in a piece of aluminum...he advises its significant weight reduction...but up to you!

Kingtal0n · 04-01-2019, 03:49 PM

Um wow. I would use it the way it was intended- Put an RB in that sucker and run it.

What can any other engine do that would sound better? Or be any better?

Even if you got an extra 100 or 300 horses from some huge turbo V8 engine it still won't sound and handle better. It isn't worth the extra power at that level in that chassis.

If you were doing a daily driver, a NEO RB25 is affordable and would do 500-600rwhp iirc on a daily pump+meth setting

otherwise a forged RB @ 800-1kbhp E85 is the way to go with something like that in racing

03-31-2019, 09:22 AM	#1
tb13 Zilvia Addict Join Date: Feb 2014 Location: Arizona ٩( ᐛ )و Subaru Parts Consultant Age: 29 Posts: 848 Trader Rating: (3) Feedback Score: 3 reviews	Need suggestions, repairing S13 firewall/trans tunnel I picked up an S13 from a friend of mine this weekend that was heavily modified to run an RB with custom mounts behind the front crossmember. This required a significant amount of the firewall to be cut out along with the trans tunnel to be hacked up. I have no interest in attempting to run a setup similar to that was intended, I am just looking to put a firewall/ trans tunnel back in the car. How would you guys go about replacing what is missing? Chop an entire firewall/trans tunnel out of a donor car or just replace what is missing? Really want to get the car back in one piece and make something of it, let me know what you guys think! __________________

03-31-2019, 09:56 AM	#2
afishysilvia Post Whore! Join Date: Jan 2010 Location: Cali Posts: 3,409 Trader Rating: (31) Rides Gallery: afishysilvia Feedback Score: 31 reviews	Drill spot welds out of donor car and swap in entire section would be correct way. __________________ Dont be a pussy...Leave your name

03-31-2019, 11:57 AM	#4
afishysilvia Post Whore! Join Date: Jan 2010 Location: Cali Posts: 3,409 Trader Rating: (31) Rides Gallery: afishysilvia Feedback Score: 31 reviews	Factory was spot welded and then body seamed. I was planning to just weld mine in completely then using sealer. I think that would be sufficient. __________________ Dont be a pussy...Leave your name

04-01-2019, 09:36 AM	#5
jedi03 Nissanaholic! Join Date: Jul 2008 Location: albuquerque Posts: 1,836 Trader Rating: (8) Feedback Score: 8 reviews	my uncle does that with his race cars and bolts in a piece of aluminum...he advises its significant weight reduction...but up to you!

04-01-2019, 03:49 PM	#6
Kingtal0n Post Whore! Join Date: Jul 2005 Location: South Florida Age: 41 Posts: 4,828 Trader Rating: (17) Feedback Score: 17 reviews	Um wow. I would use it the way it was intended- Put an RB in that sucker and run it. What can any other engine do that would sound better? Or be any better? Even if you got an extra 100 or 300 horses from some huge turbo V8 engine it still won't sound and handle better. It isn't worth the extra power at that level in that chassis. If you were doing a daily driver, a NEO RB25 is affordable and would do 500-600rwhp iirc on a daily pump+meth setting otherwise a forged RB @ 800-1kbhp E85 is the way to go with something like that in racing