Headers / exhaust upgrades (1 Viewer)

[JurisNaturalis]

Hey everyone I’m new here. Just purchased a 2001 Land Cruiser that has had a lot of modifications done to it. Even though it has the TRD supercharger, I am finding that when passing vehicles on the highway with the large gap between gears on the 4 speed, that its passing capabilities are lack lustre. I am looking to further increase the power to compensate for the 4 speed tranny. Air intake isn’t an option as it already has a snorkel. Has the supercharger. My thoughts were to install headers and a complete new exhaust to increase power. 2 questions… Doug Thorley offers short tube headers. Are they worth it or should I be trying to track down some long tube headers?
Is there an exhaust system out there that eliminates the catalytic converters? And if so, is it worth it to eliminate them?

 

[JurisNaturalis]

As others have said, if it's not fast enough for you you with a super charger you may be in the wrong truck. I personally have never felt my truck lacking (I have a 5 speed). Even with full armor and oversized tires it got around OK. I cruised at 80 all day and had plenty of get up passing. It's not a sports car by any means, but it's a 7,000# truck on 35s (now). I have full Thorley exhaust from headers back (catless, still working on the CEL fix) and while it is a noticeable improvement in terms of throttle response I doubt it will be a bigger improvement than the supercharger. Def make sure that your throttle cable is as tight as it should be, that has been an issue for multiple people who feel like they are flooring it with not enough response. The quickest way to appreciate the 100 is to find a slow truck like an old 60 series and drive that for a while! there is a thread somewhere on here that has dyno runs with the Thorley, I believe. Also, I'd be cautious with putting non proven headers on, there is very very little clearance with the frame on the driver's side especially.

Thanks. CEL fix? Did you have to do a custom pipe in place of the CATs? If not, where did you source the pipe from? Got off the phone with a lady from Doug Thorley who said they have the headers and then catback exhaust. Nothing to bridge the two.

 

[JurisNaturalis]

if you search some numbers on HP going from exhaust, youll see thats its pretty small. usually single digits. if a supercharger didnt do it for you, exhaust is going to be a waste of money and effort. just curious, what are the highway travel speeds up there? i drive my 4 speed truck at 70-80 regularly with no issues.

Just over 60mph. It has good power when I first start to pass, but then when it down shifts at near 70mph, that is when it becomes sluggish.

 

[4Beast]

Thanks. CEL fix? Did you have to do a custom pipe in place of the CATs? If not, where did you source the pipe from? Got off the phone with a lady from Doug Thorley who said they have the headers and then catback exhaust. Nothing to bridge the two.

CEL=check engine light. The shop just put a straight pipe in place of the cats between the headers and the Thorley catback. I and going to try a few options for the downstream o2 sensors to prevent the p0420/30 codes that are now affected by no cats. I can report back once I have it sorted. Having the cats is a choke point when the rest of the exhaust is open and I can't confirm that high flow ones are really high flow and will prevent codes.

 

[JurisNaturalis]

CEL=check engine light. The shop just put a straight pipe in place of the cats between the headers and the Thorley catback. I and going to try a few options for the downstream o2 sensors to prevent the p0420/30 codes that are now affected by no cats. I can report back once I have it sorted. Having the cats is a choke point when the rest of the exhaust is open and I can't confirm that high flow ones are really high flow and we'll prevent codes.

Great to know as I was planning on heading in that direction with my exhaust as well.

 

[Eyedaho]

I have doug thorley shorty headers and a dual 2 1/4" to 3" with a magnaflow 2 into 1 muffler and magnaflow hi flow cats (2 total) on my 2000. The truck feels like it picked up roughly 40hp. Motor is all stock besides that. The truck with 34" tires, stock gears, bumpers and a 2.5" lift feels the same power wise as it did completely stock. I can pull the same 5% hill on my way into work without losing speed or shifting out of OD just like it did when it was all stock.

Did you have to do some fabrication for the Magnaflow components, or did it pretty much bolt up?

 

[Wadepat2]

How would I get a reading on boost?
Also, what kind of horsepower/ torque should I be expecting from having the supercharger? When the dyno was performed

How would I get a reading on boost?
Also, what kind of horsepower / torque should I be expecting from it being supercharged? When the dyno was performed it came back with 199HP and 212FtLb torque.
View attachment 3307614

You can add boost gauge to the driver side boost port. Can ask where dyno guys got it. Boost is on your dyno sheet. Looks like 5.5 psi at wot. That's not bad really. Fuel is rich but not terrible.

Only thing off is I think you should be closer to 250-275hp at the wheels. 199 whp is pretty close to stock. Can you post some pics of your SC.

Was it tuned on dyno or just run to see the HP?

 

[peacesells63]

Did you have to do some fabrication for the Magnaflow components, or did it pretty much bolt up?

Everything from the headers back was done by an exhaust shop, it’s all custom. I brought them the cats, mufflers and header flanges and they did the rest

 

[J1000]

How would I get a reading on boost?
Also, what kind of horsepower/ torque should I be expecting from having the supercharger? When the dyno was performed

How would I get a reading on boost?
Also, what kind of horsepower / torque should I be expecting from it being supercharged? When the dyno was performed it came back with 199HP and 212FtLb torque.
View attachment 3307614

You probably are leaving some ponies on the table.

First you need to run premium fuel. Also if your spark plugs are an unknown age might be time to change them. Lastly clean the MAF and make sure you have a clean air filter. After that I'd disconnect the battery cable for a minute or so to reset the ECU with all good parts so it can tune itself in properly.

There is a plastic restrictor in the intake tube and a plastic grate, remove both to free up some air flow.

FWIW my 2007 VVTI truck made 179whp on a dyno when it was stock, so yours at 199 is not a great bump. All dynos are different, so who knows but it does seem low.

DT headers are absolutely worth it. I have a Borla exhaust also and it is a lot better than the stock exhaust also. This year I plan on changing my exhaust to a custom built 3" catback now that I have a supercharger as I think it's holding it back now.

 

[J1000]

Just over 60mph. It has good power when I first start to pass, but then when it down shifts at near 70mph, that is when it becomes sluggish.

What RPM range?

 

[Hokie LX]

The DT headers on my truck definitely woke it up. There's some dynos floating around this forum but they are noticeable to say the least. I wrote a thread detailing my install for others as reference. It's not as bad as it seems, just tight working space.

@fooldall1

LX470/100 Series Doug Thorley Headers Install Tips, Tricks, Lessons, Parts List, and Tools

Hi all, I wanted to do a thread detailing my install of my Doug Thorley headers on my 2003 LX470. I haven't seen this much detail anywhere that I could find showing the tools that make this job easier so I hope it will be helpful for someone looking to do this job by themselves. This won't be a...

forum.ih8mud.com

 

[JurisNaturalis]

What RPM range?

Downshifts to about 3100 RPM

 

[peacesells63]

How tough is the header install for a DIY?

I had both headers installed before noon one day, don't remember what time I started but it was probably about 7-8. Passenger side was easy, nothing in the way. Drivers side, I unbolted the motor mount and jacked the motor up as far as I could before the fan would contact. I replaced 6 or so studs, but had no issues with rust or stuck studs. That could add a good amount of time for sure.

 

[peacesells63]

How would I get a reading on boost?
Also, what kind of horsepower/ torque should I be expecting from having the supercharger? When the dyno was performed

How would I get a reading on boost?
Also, what kind of horsepower / torque should I be expecting from it being supercharged? When the dyno was performed it came back with 199HP and 212FtLb torque.
View attachment 3307614

That definitely seems low. Was this an AWD dyno or was it run in RWD with the front driveshaft removed?

I would expect mine to be somewhere around 180-190 wheel on a rwd dyno.

 

[dekompose559]

It’s not the hp I’m after…it’s the nice slow and rolling ***n loud rumble v8.

 

[4Beast]

It’s not the hp I’m after…it’s the nice slow and rolling f***n loud rumble v8.

It's not just the extra hp, it definitely moves the power band to higher rpms..

 

[obe12]

I am interested in this Cat Delete far as removing restriction in the exhaust, and NO Cat Efficiency Codes what's the work around for that? Cats use internal materials to chemically burn the mixture to lean the incoming exhaust for the after cat 02 sensors feedback to the eco to check for Cat Efficiency.

On Certain other cars a computer flash program will keep this active monitor from performing this check and prevent cat efficient codes to be stored / no Check Engine Lamp nor State inspection Plug in failed emissions test. In Texas there can be 1 incomplete moniter test. Usually it's the Evap Moniter based on fuel tank pressure being held in the gas tank if a reset of the ECM occurred recently. Miss Fire, O2 heater, Some 02 check, are performed during its drive cycles.

With the Cat "delete the restriction" I am curious how to trick the ECM to prevent Cat codes?

May personal LC 381K miles the resonator has been removed and aftermarket muller installed. The Exhaust under high throttle has a pressure buildup sound wishing noise under heavy throttle ands rpms indicating there is a restriction somewhere. In the stack of receipts the cat Mid pipes have been changed, it's entirely possible for the cat material from the old cats pipes has stopped up the muffler down stream.

So this Cat back full system interests me and possible cat delete the restriction. I am sourcing the DT Heeders and Cat Back now awaiting a call back. If successful I pass on the reseller... the prices are better than retail at other places I have looked. Now if they can get the parts is another thing.

Tex

 

[4Beast]

I am interested in this Cat Delete far as removing restriction in the exhaust, and NO Cat Efficiency Codes what's the work around for that? Cats use internal materials to chemically burn the mixture to lean the incoming exhaust for the after cat 02 sensors feedback to the eco to check for Cat Efficiency.

On Certain other cars a computer flash program will keep this active monitor from performing this check and prevent cat efficient codes to be stored / no Check Engine Lamp nor State inspection Plug in failed emissions test. In Texas there can be 1 incomplete moniter test. Usually it's the Evap Moniter based on fuel tank pressure being held in the gas tank if a reset of the ECM occurred recently. Miss Fire, O2 heater, Some 02 check, are performed during its drive cycles.

With the Cat "delete the restriction" I am curious how to trick the ECM to prevent Cat codes?

May personal LC 381K miles the resonator has been removed and aftermarket muller installed. The Exhaust under high throttle has a pressure buildup sound wishing noise under heavy throttle ands rpms indicating there is a restriction somewhere. In the stack of receipts the cat Mid pipes have been changed, it's entirely possible for the cat material from the old cats pipes has stopped up the muffler down stream.

So this Cat back full system interests me and possible cat delete the restriction. I am sourcing the DT Heeders and Cat Back now awaiting a call back. If successful I pass on the reseller... the prices are better than retail at other places I have looked. Now if they can get the parts is another thing.

Tex

It's possible to not have codes after a cat delete, but it takes some finagling. It is ultimately like other makes in that you will need to get the post cat sensors the right amount out of the exhaust stream and will probably be some trial and error.

 

[obe12]

It's possible to not have codes after a cat delete, but it takes some finagling. It is ultimately like other makes in that you will need to get the post cat sensors the right amount out of the exhaust stream and will probably be some trial and error.

Alrighty, I have to do some research on just that.

Heard back from the suppler that resales DT products.

Doug Thorley has picked up operations and moved to Arizona from Ca. The suppler said give it 30-45 days and revisit. DT is out of stock on these products now. Unless a retailer happens to have stock, they are temporarily unavailable.

But with time DT will be back on the scene supplying product.

Tex

 

[obe12]

Hey everyone I’m new here. Just purchased a 2001 Land Cruiser that has had a lot of modifications done to it. Even though it has the TRD supercharger, I am finding that when passing vehicles on the highway with the large gap between gears on the 4 speed, that its passing capabilities are lack lustre. I am looking to further increase the power to compensate for the 4 speed tranny. Air intake isn’t an option as it already has a snorkel. Has the supercharger. My thoughts were to install headers and a complete new exhaust to increase power. 2 questions… Doug Thorley offers short tube headers. Are they worth it or should I be trying to track down some long tube headers?
Is there an exhaust system out there that eliminates the catalytic converters? And if so, is it worth it to eliminate them?

Another option is gearing for the large heavy cruiser wagon. Either differentials or even under drive in the transfer case. If you increase tires it essentially changes the gearing and adds drag, I am in the middle of hearing change in the transfer case. Underdrive with part time 4x2 all of this other that have done it have seen performance increases.
I run 33 inch tires now, stock axle gearing 4:30. Now the under drive essentially creates the ratio like 4:56 gearing.

Just another thought

 

[dekompose559]

i have found some great Aussie companies. They solved all that for you with one of their brown series. Look up Aussie off-roading currently I cannot find any USA manufactured that are not back ordered out of stock etc reasons. These aussies are badass made to order and are in stock! I’ll link page here I’m buying a complete header to exhaust from them and I’m keeping cats. Deleting them you will not pass smog here in California best to run high flows and change them out and put stock back when time to smog which is a hassle coming from the Honda world we also pay high smog fees lol but I’ve heard you can reprogram ecu

Toyota Landcruiser 100 Series V8 4.7L Petrol 1998/2008 - Single 3" wit

Product Description Experience the unparalleled power and reliability of a King Brown Exhaust System. Constructed with top-grade 409 stainless steel, this exhaust system is exceptionally tough and durable. Australian Made for Australian Conditions. With superior quality and high performance...

pacemaker.com.au

TOYOTA LANDCRUISER 100 SERIES UZJ100 4.7LT V8 HURRICANE HEADERS EXTRACTORS

TOYOTA LANDCRUISER 100 SERIES UZJ100 4.7LT V8 HURRICANE HEADERS EXTRACTORS

www.performanceexhaust.com.au