Initial thoughts and review; Doug Thorley Cat-back

[Sayer Lane]

For those looking for a review of the Doug Thorley cat back system.

The initial unboxing had me surprised. The piping was far thicker and heavier than expected, in a good way. The welds were clean and the bends were perfect. The only thing lacking from the kit were the exhaust gaskets, as the instructions say to reuse the old gaskets. (Which I did not do nor do I recommend) the clamps and hardware on the other hand, were provided and were very stout.

The install was extremely straight forward and easy to say the least. Leave the pipes loose until they’re all in and fitted and tighten from the front back. It would’ve taken me probably less then an hour from start to finish if I was not dealing with some rusted hardware and less than spectacular previous repairs to the exhaust.

Now for my initial impression on start up and the first drive after install. This system is not quiet, I REPEAT IT IS NOT QUIET. With that said it’s not extremely loud but it’s throaty. In my opinion it sounds great, just enough volume and that great throaty exhaust sound. For those wondering if there’s a drone; yes there is a drone. For me it’s at 57-62 MPH or 2000-2200 RPM. It’s not terrible but for those who may not like or can’t tolerate it, I wouldn’t recommend this system. I’ve had a few different vehicles with different exhaust systems, flow master 40 series,super 44 series, and 50 series. I’ve had cherry bomb glass packs and straight pipes as well, in my younger/dumber years. This compares closest to the 50 series flowmaster in my opinion if anyone is familiar. No popping or super loud but the classic throaty exhaust tone. I hope this helps anyone who may be on the fence or unsure about this system. If you have any questions I’ll do my best to answer.

 

[balance156]

Hey there. Appreciate your review. How about power and fuel efficiency? Anything worth mentioning?

 

[ga12r1]

For those looking for a review of the Doug Thorley cat back system.

The initial unboxing had me surprised. The piping was far thicker and heavier than expected, in a good way. The welds were clean and the bends were perfect. The only thing lacking from the kit were the exhaust gaskets, as the instructions say to reuse the old gaskets. (Which I did not do nor do I recommend) the clamps and hardware on the other hand, were provided and were very stout.

The install was extremely straight forward and easy to say the least. Leave the pipes loose until they’re all in and fitted and tighten from the front back. It would’ve taken me probably less then an hour from start to finish if I was not dealing with some rusted hardware and less than spectacular previous repairs to the exhaust.

Now for my initial impression on start up and the first drive after install. This system is not quiet, I REPEAT IT IS NOT QUIET. With that said it’s not extremely loud but it’s throaty. In my opinion it sounds great, just enough volume and that great throaty exhaust sound. For those wondering if there’s a drone; yes there is a drone. For me it’s at 57-62 MPH or 2000-2200 RPM. It’s not terrible but for those who may not like or can’t tolerate it, I wouldn’t recommend this system. I’ve had a few different vehicles with different exhaust systems, flow master 40 series,super 44 series, and 50 series. I’ve had cherry bomb glass packs and straight pipes as well, in my younger/dumber years. This compares closest to the 50 series flowmaster in my opinion if anyone is familiar. No popping or super loud but the classic throaty exhaust tone. I hope this helps anyone who may be on the fence or unsure about this system. If you have any questions I’ll do my best to answer.

Great review. My 2 cents....I really enjoyed having the DT system on my 100. It just made the truck so much more fun to drive. As far as the drone goes I just drove a little faster or slower and if that wasn't possible I just dropped out of overdrive. I think you will really enjoy it as time goes by.

 

[Sayer Lane]

Hey there. Appreciate your review. How about power and fuel efficiency? Anything worth mentioning?

Fuel efficiency is a big fat no for me, or I guess I should say, marginal if any at all. I also don’t drive with an easy throttle foot. It did seem to give me a little more power, but it could be all in my head. My original exhaust was shot though, the muffler and resonator were both rattling and could very possibly had a slight obstruction in both. My exhaust pipes were also cracked at both the muffler inlet and resonator inlet which leads me to believe I gained some back pressure which would then theoretically give back some lost power. It’s definitely made it more fun to drive, as I enjoy the sound of a throaty exhaust and boy do these 4.7’s sound good.

 

[Sayer Lane]

Great review. My 2 cents....I really enjoyed having the DT system on my 100. It just made the truck so much more fun to drive. As far as the drone goes I just drove a little faster or slower and if that wasn't possible I just dropped out of overdrive. I think you will really enjoy it as time goes by.

That’s exactly what I’ve been doing with the drone. It’s not so much a huge deal for me, as much as I wanted to make sure others were aware. I’ve seen countless post on here and the UZJ100 group on Facebook of people who hated the system due to the drone. I get it though, these from the factory were pretty quiet and for those looking to replace the factory with a slightly more aggressive system, this one might be a shocker for some.

 

[CanyonLX]

Where did you buy your system?

 

[Sayer Lane]

Where did you buy your system?

1998-05 Toyota Land Cruiser Lexus LX470 Doug Thorley Cat Back Exhaust Kit 89248 | eBay

Find many great new & used options and get the best deals for 1998-05 Toyota Land Cruiser Lexus LX470 Doug Thorley Cat Back Exhaust Kit 89248 at the best online prices at eBay! Free shipping for many products!

www.ebay.com

 

[balance156]

Fuel efficiency is a big fat no for me, or I guess I should say, marginal if any at all. I also don’t drive with an easy throttle foot. It did seem to give me a little more power, but it could be all in my head. My original exhaust was shot though, the muffler and resonator were both rattling and could very possibly had a slight obstruction in both. My exhaust pipes were also cracked at both the muffler inlet and resonator inlet which leads me to believe I gained some back pressure which would then theoretically give back some lost power. It’s definitely made it more fun to drive, as I enjoy the sound of a throaty exhaust and boy do these 4.7’s sound good.

Thanks for the detailed reply. I currently have the muffler delete and it sounds very very good (both at start up, idle and under throttle) but I’ve been looking for more power.

Fuel efficiency is a big fat no for me, or I guess I should say, marginal if any at all. I also don’t drive with an easy throttle foot. It did seem to give me a little more power, but it could be all in my head. My original exhaust was shot though, the muffler and resonator were both rattling and could very possibly had a slight obstruction in both. My exhaust pipes were also cracked at both the muffler inlet and resonator inlet which leads me to believe I gained some back pressure which would then theoretically give back some lost power. It’s definitely made it more fun to drive, as I enjoy the sound of a throaty exhaust and boy do these 4.7’s sound good.

Thanks for the reply. I currently have the muffler delete and it sounds very very good (at start up, idle and under load) with zero drone. I had a borla off road cat back on my old F-150 and it had horrible drone, but at a much broader RPM range and I typically don’t drive my LX at 57-62mph, usually slower or faster. Also passes smog at my local shop
I’m just looking for more power and if this provides something worthwhile then the $470 could be worth it.
Do you have a 4 or 5 speed?

 

[Sayer Lane]

Thanks for the detailed reply. I currently have the muffler delete and it sounds very very good (both at start up, idle and under throttle) but I’ve been looking for more power.

Thanks for the reply. I currently have the muffler delete and it sounds very very good (at start up, idle and under load) with zero drone. I had a borla off road cat back on my old F-150 and it had horrible drone, but at a much broader RPM range and I typically don’t drive my LX at 57-62mph, usually slower or faster. Also passes smog at my local shop
I’m just looking for more power and if this provides something worthwhile then the $470 could be worth it.
Do you have a 4 or 5 speed?

I have the 4 speed. I honestly think that the drone could be eliminated if some extra sound deadening were added to the rear and under the carpet. So far I’m okay with it but if I finally get to where I’m over it I’ll try the sound deadening. As for power, the most notable difference for me is throttle response on take off and passing someone. Other than that it seems the same.

 

[pawwright]

I have the 4 speed. I honestly think that the drone could be eliminated if some extra sound deadening were added to the rear and under the carpet. So far I’m okay with it but if I finally get to where I’m over it I’ll try the sound deadening. As for power, the most notable difference for me is throttle response on take off and passing someone. Other than that it seems the same.

I think there are a couple of threads of people that added resonators somewhere in the exhaust pipe to get rid of the drone - it doesn't bother me enough to do anything about it, either.

 

[bigjer]

Hooker aero chamber muffler is the way to go, no interior drone at all and sounds good.

 

[Hokie LX]

Hooker aero chamber muffler is the way to go, no interior drone at all and sounds good.

any videos?

 

[ZREM]

This is a very accurate review of this cat back, well done.

I've had it on my 4spd 100 for a couple years now and it's getting to me. I'll likely be looking to swap out the muffler for something a bit tamer. When towing, the drone can really wear on you.

 

[Hokie LX]

This is a very accurate review of this cat back, well done.

I've had it on my 4spd 100 for a couple years now and it's getting to me. I'll likely be looking to swap out the muffler for something a bit tamer. When towing, the drone can really wear on you.

The towing comment is why I haven't pulled the trigger on it. I tow a 6x12 enclosed trailer to races and am concerned about drone. My headers are cracked so I think I'm going to get the DT headers and see how the tone is before I decide on exhaust.

 

[Ray Guy]

For those looking for a review of the Doug Thorley cat back system.

The initial unboxing had me surprised. The piping was far thicker and heavier than expected, in a good way. The welds were clean and the bends were perfect. The only thing lacking from the kit were the exhaust gaskets, as the instructions say to reuse the old gaskets. (Which I did not do nor do I recommend) the clamps and hardware on the other hand, were provided and were very stout.

The install was extremely straight forward and easy to say the least. Leave the pipes loose until they’re all in and fitted and tighten from the front back. It would’ve taken me probably less then an hour from start to finish if I was not dealing with some rusted hardware and less than spectacular previous repairs to the exhaust.

Now for my initial impression on start up and the first drive after install. This system is not quiet, I REPEAT IT IS NOT QUIET. With that said it’s not extremely loud but it’s throaty. In my opinion it sounds great, just enough volume and that great throaty exhaust sound. For those wondering if there’s a drone; yes there is a drone. For me it’s at 57-62 MPH or 2000-2200 RPM. It’s not terrible but for those who may not like or can’t tolerate it, I wouldn’t recommend this system. I’ve had a few different vehicles with different exhaust systems, flow master 40 series,super 44 series, and 50 series. I’ve had cherry bomb glass packs and straight pipes as well, in my younger/dumber years. This compares closest to the 50 series flowmaster in my opinion if anyone is familiar. No popping or super loud but the classic throaty exhaust tone. I hope this helps anyone who may be on the fence or unsure about this system. If you have any questions I’ll do my best to answer.

Can anyone tell me why this dose not fit the 1998 year ? Says fot 1999-2005 land cruiser

 

[Sayer Lane]

Can anyone tell me why this dose not fit the 1998 year ? Says fot 1999-2005 land cruiser

I don’t see any reason why it wouldn’t work or fit. From my understanding the only difference in the exhaust through the years are the manifolds for air injection of the VVT vehicles.