Maximizing FZJ80 supercharger performance

[Snorkel 1]

I have two 1997 80's that are almost identical mechanically but one has noticably more power than the other. Here are the specifics:

TLC 1:
115,000 miles
Supercharged
NGK plug wires
Factory intake
Magnaflow exhaust
4.10 gears

TLC 2:
185,300 miles
Supercharged
Factory plug wires
Safari snorkel
Spark plugs changed 9 months ago or so
Factory exhaust
4.10 gears
(this is the one I have listed for sale)

TLC 2 has noticably more power off the line and when passing. Could it be that I just need a tune up? Could the transmission have that effect with no other symptoms? O2 sensors? Compression has not been checked on either since I have owned them.

I meant to post this long ago but now it became more urgent just incase I need to compair anything on them before I sell TLC 2.

Thanks.
Seth

 

[RavenTai]

That is a pretty wide question.

The snorkel could be part of it, the factory intake brings in a lot of hot air. With forced induction this could lead to detonation and resulting ignition timing retardation by the ECU, try premium gas, but the hot air still reduces the density of the intake charge even if you are not pinging.

The exhaust could be another, aftermarket exhaust can help or hurt depending on design and what the motor needs, main effect is velocity out of the exhaust port ands its effects on scavenging. Generally cat back systems do not have much of an effect either way.

I do not know specifically how reliable the TRD supercharger is but in general superchargers can develop seal problems where the pressure they produce is reduced.

could also just be LC#1 has engine troubles, overheating, carbon on the pistons, low compression, uneven flow in the injectors, out of spec valve lash, bad timing, poor valve seat, vacuum leaks, exhaust leaks that bring in air before the O2 sensor, etc etc

 

[Snorkel 1]

Here is a reply I got from the same post on the Rising Sun Forum:


How's the timing between the two? On my supercharged 80 3* of initial timing makes a HUGE differance! Right now I'm at near stock initial timing and running the stock charger pulley and have the rising rate regulator vacuume line pulled so I can run mid grade fuel because of rising gas prices....I can barely beat a 4.7 runner right now but the MPG is back up to 14-15ish.
Just bumping the timing up 3* and running premium will completely change the whole torque curve and bring it in sooner!
The snorkle could be helping too as cooler/denser air will carry atomized fuel in suspension much better!

I will try the timing first and go from there. Any other thoughts?

Seth

 

[cruiserdan]

I noticed a "crisper" throttle when I added the snork. I could not tell you how much but I did notice it. Do you have boost gauges? Maybe the faster one has a bit more boost. I would suggest getting a bost gauge and check both vehicles with the same gauge and see what that tells you.