gday, im after a set of extractors for my L18 an i was wondering which are the best "bang for your bucks" so to speak.

Cheers,
Tristan.

not too sure on best bang for buck, but i picked up my 4-1 pacemakers for 90 delievered from sydney. theyre brand new, and heat wrapped all the way down. the guy that had em never had em fitted and was cleanin out his shed

apparently the 4-1 design is better for race applications, and 4-2-1 better for street as they produce more torque.

cheers,
dave

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Dave W

The 1600

Recommended traders: Nissanman, pro240c, 2door510, Datsport, mkyle, Green510, Um_510, jdmdatsun510, Ludachris

Not sure how the L4 exhaust manifolds compare to the L6, but lot's of testing on USA prod car racing L24 motors showed that there was very little to gain when changing the exhaust manifold unless the motors were seriously modified. I'd spend the money on something useful, like a cam or head porting (the exhaust ports generally suck). Not to say that replacing the exhaust system post exhaust manifold isn't worthwhile...

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Michael
'71 240Z, RB20DET.
'89 Nomad (needs speed).

my car came with the factory curtain rod for an exhaust.
i found a set of Y-motivator extractors and a turbo muffler/tailpipe for $50.00
$20.00 for an exhaust gasket
cost me another $100.00 for fitting and the the bit of 2 1/2" pipe to go between the extractors and the tailpipe.
I think the exhaust guy ripped himself off

early L18 factory exhaust manifolds are the best IMO for anything up to about 150hp. under that power level, to me, the end doesn't justify the means (and the means is $$$).

a nice tuned lenght may get you more torque and bit more up top, but the cost for that actual gain, percentage wise, is just too much.

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frankenstein projects R us.

The Republic of Western Australia -
Propping up the Nation's Economy since 1901.

I would GUESS ( i don't run any L4 ) that it is a perfectly worthwhile modification if you are going to be working the engine more in the future, and if you are a little spanner-shy, it is something that is easy enough to change, and will still give you a performance increase (placebo perhaps, but more N/A mods are aren't they?).

The problem is that there is always a bottleneck. If you change the extractors to wizz bang ones you might get an extra 3hp because it just moves to the next bottleneck even though the extractors might give a 40hp increase on a proper race engine.

Hope that makes something resembling sense.

Pro, got a 150hp L18 with a stock manifold?

Dave

_________________
USA Daily: 2014 Nissan GT-R, very minor modifications for the track
USA Project: 1978 280Z, minor suspension upgrades, VK56DE conversion in progress. SOLD
AUS Race Car: 1973 240Z, L28ET, Autronic, GT35R. SOLD
AUS Project: 1972 1600, 3200km old S15 SR20DET, ground up rebuild. SOLD

i had one! back in the days i didn't know much about Ls (still don't compared to most people!) one of my friends built an L18 for me.

the restriction was JUST staring to show with it, had a ported A87 head with L6 valves and dbl valve springs, my 55DCOE carb (god bless that baby) and about 10.2:1 CR with cast pistons (ACLs? dunno - didn;t build the bottom end).

anyways, i went from a "lumpy cam" to a "very lumpy cam" and the power dropped off in the top end and didn't like to rev much over 6500.

swapped them for a good set of 4into1s and got my redline back (7800) and about 25hp with it. could have gotten more had i choked the weber properly and fitted more suitable jets (straight off a large EP 13B).

so that's my experience. if you have a different combo then different effects but yeah, that's my story.

_________________
frankenstein projects R us.

The Republic of Western Australia -
Propping up the Nation's Economy since 1901.

Awesome. Real world experience counts for a lot.

Dave

_________________
USA Daily: 2014 Nissan GT-R, very minor modifications for the track
USA Project: 1978 280Z, minor suspension upgrades, VK56DE conversion in progress. SOLD
AUS Race Car: 1973 240Z, L28ET, Autronic, GT35R. SOLD
AUS Project: 1972 1600, 3200km old S15 SR20DET, ground up rebuild. SOLD

i wish hindsight counted for a lot.

i sold it along with the car it was going into, because CA conversions werea ll the rage and someone said "how much better" CAs were over Ls.

spewing really, it was an awesome car and that engine would have made it even better.

_________________
frankenstein projects R us.

The Republic of Western Australia -
Propping up the Nation's Economy since 1901.

well put it this way, my L18 is going to have a port job, a 72 deg cam, and either twin 40mm or 45mm webers. (with stock crank/rods/pistons). Approximately how many HP will that give it (correctly tuned and jetted) and will extractors be necessary?

Cheers,
Tristan.

It will have more of an improvement with those mods yes. Necessary to make it run, no, but if you don't it will quite possibly be costing you power.

Dave

_________________
USA Daily: 2014 Nissan GT-R, very minor modifications for the track
USA Project: 1978 280Z, minor suspension upgrades, VK56DE conversion in progress. SOLD
AUS Race Car: 1973 240Z, L28ET, Autronic, GT35R. SOLD
AUS Project: 1972 1600, 3200km old S15 SR20DET, ground up rebuild. SOLD

Was told this from a Datsun/Nissan trained mechanic.

The L20B "smooth faced" manifold (the one with no casting marks on the top of the runners) is good for around 180hp.
On the stock manifold the casting marks go "into" the ID of the runners.
Not so with the "smooth faced" manifold.
Not all L20b's came with this manifold.
I do have on lying around and will take a photo and post it up if I can find it.

I'm using a set of 4-2-1 extractors on my L18 for my P510/1600 resto but only because they are HPC coated and only cost me $120 bucks.
Otherwise I would use the above mentioned manifold.

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1975 P610/180B SSS ex PRC3 Rally car (parts car)
1974 P610/180B SSS (parts car)
1972 P510/1600 Currently sitting untouched
1977 P610/180B Wagon Daily Driver

well, by the sounds of it you'll be making more than 150hp so yes, i reckon go some tuned length 4into1 extractors.

i still say $250 per pot is cheap after trying to build my exhaust 3 times over.

_________________
frankenstein projects R us.

The Republic of Western Australia -
Propping up the Nation's Economy since 1901.

Ok, i know pacemaker have "tri Y's" but not 4 into 1's, is there a brand of header that sells 4 into 1's for L series 4's?

Cheers,
Tristan.

it all depends on what you want ou tof your engine.

my advice is speak to someone who can give you better advice than i can.

_________________
frankenstein projects R us.

The Republic of Western Australia -
Propping up the Nation's Economy since 1901.