Full 3 Inch Exhaust + CAI Test

[ToyotaIsLife]

Hello, I just got this 2003 100 Series Land Cruiser with the A750 5 Speed Auto and the 2UZ-FE 4.7L V8. This is my first 100 series with a V8 instead of a 1FZ-FE inline 6 that I am accustomed too.

I installed 4-2-1 headers with 1 3/4 primaries and a 2.5 inch collector which goes to 3 inch down pipes (no cats) to a straight through turbo mid muffler (similar to the MagnaFlow brand, perforated core design) the down pipes after the collector merge into one right before connecting to the mid muffler. Finally it goes to a 3 inch straight through tail pipe resonator.

The CAI was a new K & N Cold Air Intake.

The acceleration improved significantly, I attribute most of the gains to the cat delete since it had the original cats from day one, they were probably at least partially clogged.

It went from a 0-60 MPH of 9.8 seconds to a 0-60 MPH of 7.6 seconds (tested on a draggy 10hz GPS device on the same road from the same starting point) which is a pretty good improvement.

Up next is a standalone ECU.

Sound video (acceleration test at the end):

 

[excessive]

That is an extremely impressive difference in 0-69 times. Can't want to hear more about the standalone ECU, there must be 2UZ wizards there who know what they're doing with tuning

 

[4Beast]

In my experience not having cats is definitely the difference. I had a catback with stock cats and manifold and the sound and performance was understated, then added headers and no cats and it was raucous and made a significant difference, especially at a higher RPM range. Now I put 3" high flow cats in and it's a bit more muted and a little less responsive, but still louder and stronger than stock or with the cat back. I also have a snorkel, which is basically a CAI. Getting tuned this weekend...

 

[ToyotaIsLife]

That is an extremely impressive difference in 0-69 times. Can't want to hear more about the standalone ECU, there must be 2UZ wizards there who know what they're doing with tuning

Pretty sure it will pick up a considerable amount everywhere especially down low. Since from my experience viewing OEM base files in 2008+ Toyota Land Cruiser ECUs, Toyota severely undertimes the ignition map at high load low RPM. We are talking 0-5 degree of advanced ONLY! at full throttle up till peak torque and after that it starts adding advance.

Which makes sense from a Toyota max reliability philosophy, especially since at high load low RPM cylinder pressures are higher (being their highest right at peak torque), higher chance of pre-ignition/detonation/knock.

Ignition timing alone will probably add 20+ HP possibly even 40HP considering the headroom available.

Other then that from my experience Toyota targets a extremally rich fuel mixture at full load, specifically 10.58 AFR or 0.72 Lambda, also makes sense for long term reliability (keeping cats from overheating, keeping cylinder temps lower, reducing chance of knock).

So targeting 0.88 Lambda or around 12.8 AFR should also boost power quite a bit coming from 0.72 Lambda/10.58 AFR.

Not to mention forcing the ignition coils to have a higher dwell time for increased spark energy and refining the injector timing.

Plus I will have full control over the factory DBW throttle body so I can make it more responsive, that coupled with the speed of the new aftermarket ECU's like Maxxecu which I will be running AND the transient fuel strategies that are available in this ECU it will be much more responsive.

With the standalone ECU, I will be completely getting rid of the factory ECU & TCM, meaning I will have full control over gear shifts (shift solenoid outputs will be connected as outputs to the aftermarket ECU), meaning I can incorporate ignition cut on gear shift alongside a throttle blip making it shift like a high performance vehicle, gonna be fun.

 

[ToyotaIsLife]

In my experience not having cats is definitely the difference. I had a catback with stock cats and manifold and the sound and performance was understated, then added headers and no cats and it was raucous and made a significant difference, especially at a higher RPM range. Now I put 3" high flow cats in and it's a bit more muted and a little less responsive, but still louder and stronger than stock or with the cat back. I also have a snorkel, which is basically a CAI. Getting tuned this weekend...

Agreed cats make the biggest difference, then headers, then mid muffler.

 

[Coin]

So if I pulled my 330,000 miles cats, I'd have better throttle response and acceleration. How much louder is it? How much worse are the exhaust fumes?
I'd love a quicker truck, but I like my fairly quiet cabin and the lack of significant exhaust fumes.

 

[ToyotaIsLife]

So if I pulled my 330,000 miles cats, I'd have better throttle response and acceleration. How much louder is it? How much worse are the exhaust fumes?
I'd love a quicker truck, but I like my fairly quiet cabin and the lack of significant exhaust fumes.

You can smell the exhaust fumes especially during cold starts but I developed a tolerance so I don’t notice it as much anymore. All else remaining stock just deleting the cats wouldn’t cause that much increased noise it will just be a little throatier.

 

[J1000]

Really good results, your truck is faster 0-60 than mine is with a supercharger! I am at 6000ft elevation though. Very interesting to hear the thoughts on the cats, I'm planning on doing high flow at some point, maybe I will do it sooner than later. @ToyotaIsLife your description of how the stock ECU runs the engine lines up with my observations as well, probably a lot more performance to be had with just minor changes. I tried to use a piggyback to do that but the stock ECU would always compensate and pull additional timing and add fuel no matter what I did. Probably some MPGs to unlock with timing advance as well. Towing a trailer up a mountain pass at 10.5:1 AFR gives me about 6 MPG if I'm not careful

 

[ToyotaIsLife]

Really good results, your truck is faster 0-60 than mine is with a supercharger! I am at 6000ft elevation though. Very interesting to hear the thoughts on the cats, I'm planning on doing high flow at some point, maybe I will do it sooner than later. @ToyotaIsLife your description of how the stock ECU runs the engine lines up with my observations as well, probably a lot more performance to be had with just minor changes. I tried to use a piggyback to do that but the stock ECU would always compensate and pull additional timing and add fuel no matter what I did. Probably some MPGs to unlock with timing advance as well. Towing a trailer up a mountain pass at 10.5:1 AFR gives me about 6 MPG if I'm not careful

Yes exactly.

remember that adding boost only amplifies the current power curve.

Your stock ECU is probably going haywire since it’s not scaled for boost you will benefit so much from a standalone ECU.

Not to mention switching to wideband LSU 4.9 sensors for precise lambda monitoring and both close loop fueling + long term fuel adaptation capabilities of modern ECUs such as the motec M1 lineup and the maxxecu.

I sincerely hope you upgraded your fuel pump too, keep that pressure always high and stable.

 

[J1000]

Yes exactly.

remember that adding boost only amplifies the current power curve.

Your stock ECU is probably going haywire since it’s not scaled for boost you will benefit so much from a standalone ECU.

Not to mention switching to wideband LSU 4.9 sensors for precise lambda monitoring and both close loop fueling + long term fuel adaptation capabilities of modern ECUs such as the motec M1 lineup and the maxxecu.

I sincerely hope you upgraded your fuel pump too, keep that pressure always high and stable.

Yep, partly I am happy keeping it tuned 'soft' so I don't have to worry about bending rods. Using AEM fuel pump and I have an AEM wideband gauge I can monitor while driving.

 

[ToyotaIsLife]

Yep, partly I am happy keeping it tuned 'soft' so I don't have to worry about bending rods. Using AEM fuel pump and I have an AEM wideband gauge I can monitor while driving.

It would be really juicy if you went with JE forged slightly dished pistons with crown coating with BC H-Beam steel rods. ARP head studs.

1050 injectors from injector dynamics.

Walbro 535 LPH no check valve fuel pump combined with a 525 LPH with check valve as a secondary.

Then up the boost to 15 PSI.

Don’t mind me as I drool a little bit day dreaming.

 

[4Beast]

So if I pulled my 330,000 miles cats, I'd have better throttle response and acceleration. How much louder is it? How much worse are the exhaust fumes?
I'd love a quicker truck, but I like my fairly quiet cabin and the lack of significant exhaust fumes.

In my experience you'd have much better throttle response etc, and also it would be loud and you would have lots of hydrocarbon fumes. I didn't notice the smell in the cabin, but it was strong outside the running truck, but then again I lost 90% my sense of smell after Covid.