Looking at several GX470's , a few are 2003-2004 with modest suspension upgrades and 75.00ish miles and a few 08-09's with 90k miles. Am I better off with the newer higher mileage and more power engines or should I get the older lower power v8 and upgrade? Can the 03-05 be tweaked for more power with long tube headers,exhaust and tuning?
2006-2009 only ?
- Thread starter beungood
- Start date
This site may earn a commission from merchant affiliate
links, including eBay, Amazon, Skimlinks, and others.
Yes and no. Do you just mean upgrade as in headers, etc or modifying the ecu? The 2005-2009 added VVTI (and, unfortunately, Secondary Air Intake System). The newer motors are more vulnerable to catostrophic engine failure if the timing belt fails, but it isn't wise to leave it that long anyway. Some tuners can tune the earlier models, but there are more specific out of the box tunes for the newer model years. I have an 06. The difference between 70-90k on these motors is nominal. I would be most concerned with rust. Some had frames replaced by the Toyota because of that issue. Most other systems are unchanged fron year to year except the audio systems. 2006 added BT calling. 2007 added BT call and streaming and XM radio was an option. It is much easier to find replacement engibes for the 03/04 models but that is unlikely to be an issue unless it was neglected (like mine was when I got it). Exhaust manifolds are a common failure point so Doug Thourley headers are the way to go and run about the same as the oem manifolds (because oem have cats on them). 05 and up have the plumbing for the SAIS in the headers as well so those pipes need to be specific to the earlier vs later generation models. Hope that helps. BTW, if air suspension is in good shape, keep it as l Iong as you can unless you are planning to do offroading in it, especially if you plan to tow with it.
- Thread starter
- #3
The older vehicles ive found I like better than the newer ones but I wondered if I went with an older motor can I get more power to equal the later years? Somoen offered me an 04 thats had aftermarket Suspension and it looks fairly well taken care of.
Second the air suspension, if I was doing this all over again I'd keep the system and use airbag man setup. Too late now, chopped all that stuff out. Had to swap rear springs last year as I now carry more weight than when I originally lifted it. Would have been slick to have it still self adjusting for load.
older low power ones don't have secondary air injection issues, drive one and see if it's fast enough for you, I wouldn't consider them slow. most important thing is to get one in good condition.
The SAIS is easy to delete with a Hewitt kit. 30 extra horsepower is 30 extra horsepower, chances are you won't regret getting a 2005+ 
. You're also getting a slightly newer rig, which does matter considering things like electrical connectors, rubber components, and interior plastics start to get brittle at age. The TB issue is over ratted, the VVTI motors are only interference when the VVTI is activated. I suppose if you break a timing belt at a full-throttle run with VVTI engaged you can bend all 32 valves, but that would only happen if someone was negligent in never changing the timing belt.
The VVTI rigs have the same exhaust manifold issues as the pre-VVTI motors and headers are slightly more expensive. Even with headers on a pre-VVTI motor, you might get a bit closer to a stock VVTI engine in power, but a VVTI motor with headers will still be 30 HP ahead.
My VVTI motor runs very, very well with LT headers, an exhaust, cold air intake, and tune. Great passing power with the midrange torque from the mods plus the VVTI upper-end horsepower.
. You're also getting a slightly newer rig, which does matter considering things like electrical connectors, rubber components, and interior plastics start to get brittle at age. The TB issue is over ratted, the VVTI motors are only interference when the VVTI is activated. I suppose if you break a timing belt at a full-throttle run with VVTI engaged you can bend all 32 valves, but that would only happen if someone was negligent in never changing the timing belt. The VVTI rigs have the same exhaust manifold issues as the pre-VVTI motors and headers are slightly more expensive. Even with headers on a pre-VVTI motor, you might get a bit closer to a stock VVTI engine in power, but a VVTI motor with headers will still be 30 HP ahead
.My VVTI motor runs very, very well with LT headers, an exhaust, cold air intake, and tune. Great passing power with the midrange torque from the mods plus the VVTI upper-end horsepower.
- Thread starter
- #7
Whats the secondary air injection issues?
If SAP fails and you want to replace it the job is a huge pain. Under the intake past the starter against/under the firewall. Bypass is an option.
Nav vs. no Nav should be a consideration for your GX. A non nav regardless of year is good for upgrading.
Air suspension FTW IMHO.
Nav vs. no Nav should be a consideration for your GX. A non nav regardless of year is good for upgrading.
Air suspension FTW IMHO.
the hewitt kit works fine on most other toyotas but has alot of issues with the 2uz. It only works sometimes and alot of times you'll get check engine light codes and limp mode. Not sure what the laws are like were the OP is from but removing emissions equipment is always federally illegal.The SAIS is easy to delete with a Hewitt kit. 30 extra horsepower is 30 extra horsepower, chances are you won't regret getting a 2005+
The VVTI rigs have the same exhaust manifold issues as the pre-VVTI motors and headers are slightly more expensive. Even with headers on a pre-VVTI motor, you might get a bit closer to a stock VVTI engine in power, but a VVTI motor with headers will still be 30 HP ahead
My VVTI motor runs very, very well with LT headers, an exhaust, cold air intake, and tune. Great passing power with the midrange torque from the mods plus the VVTI upper-end horsepower.
I have the Hewitt kit and do not have any issues. I also installed block off plates and removed the SAIS tubes. The trick is to proactively delete the SAIS before it has problems.
Unless the OP is in a state with robust visual inspections the kit will never be noticed.
Unless the OP is in a state with robust visual inspections the kit will never be noticed.
Another guy with a successful Hewitt kit install here. Takes minutes and is basically invisible. Shouldn't stop anyone from buying a VVTi truck.
In the end, I think I would pick the most rust free and maintained example you can find. Rust is the killer here.
In the end, I think I would pick the most rust free and maintained example you can find. Rust is the killer here.
I'm glad to hear the kit is working for you. from the Hewitt site: "**There is a known “Cold Weather Glitch” on some older 4.7L engines. If the vehicle is tripping a P2445 and it is caused by this glitch; the Hewitt Technologies SAIS Bypass Kit will not resolve the issues. Please visit our Error Codes page or give us a call to learn more."
I don't install these kits but i have seen customer's trucks with this issue.
I don't install these kits but i have seen customer's trucks with this issue.
Love my 07. i think VVTI is the way to go. 240k trouble free miles on mine. i did the SAIS bypass and have been good to go ever since.
More importantly, why are you bothering to buy a Lexus with low miles? These last forever. I bought mine with 290k on it, shines like new. Save the money for modifications, as they are much needed if you want to do any serious off-roading.
- Thread starter
- #15
What is the Airman bag set up?
- Thread starter
- #16
I am in Mass (for right now).
Airbag Man makes rear lift bags that work with the factory ride height control system. They're just taller airbags. A functioning rear air ride is superior to a coil spring conversion in every way and I wish I had left mine too.
I did Airbagman on mine sometime last year. Super simple and worth it in my opinion. Ordered from Australia and came in about 2 weeks later.
Also, I have OME 2” coil overs in the front with matching shocks on the rear.
You can always supercharge it for more HP!
