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Increasing horsepower using thermal barrier under intake manifold
1998-2000 LS400 (1UZ-FE).and 2001-2006 LS430 ((3UZ-FE) and 2UZ-FE employ large Aluminum intakes that heat soak from the engine.
Beginning ~1998, Toyota employed composite sandwiched between metal gaskets between the cylinder heads and intakes in an effort to reduce heat transmission to the intake, yet did not address radiant heat from the engine valley.
Heat barrier intake manifold gasket was a partial solution.
Our Aluminum manifolds are uncomfortable hot to touch.
A Corvette article discusses plastic intake experiencing considerable heat soak.
An insulating barrier material was employed and before/after dyno charts depicts increased power across the torque curve.
So, I removed intake on 1999 LS400 and applied DEI Floor & Tunnel Shield to the bottom of the intake manifold.
This is a high quality heat and sound barrier material that employs an Aluminum scrim and insulating material with high tack pressure sensitive adhesive.
Several project images;
Super heavy Aluminum intake manifold from 1999 LS400. Soaks up an incredible amount of engine heat. Could almost fry an egg.
Bottom side of intake manifold. So much heat in intake valley that had to replace crumbling plastic connector shells on knock sensors and starter Tailored paper template. Profile of ounting bosses for vacuum reservoir, wire harness clamp and plastic vacuum hose clamp are about 5/16", so adequate clearance for DEI barrier.
Paper template atop DEI material ready for cutting.
Installed DEI heat shield also serves as a sound barrier/absorbing material...
All manifold parts returned to their original position without interference from heat shield
Have you tuned your ECU yet or are you still on the stock program? I constantly see you making changes that won't ever manifest if you don't change the ECUs priorities and map......I can assure you that even with everything you have done if you never tuned it the output will be unchanged with only more economy as the gain.
Have you tuned your ECU yet or are you still on the stock program? I constantly see you making changes that won't ever manifest if you don't change the ECUs priorities and map......I can assure you that even with everything you have done if you never tuned it the output will be unchanged with only more economy as the gain.
i say that and he refers to it as a 'blanket of scoff' lol
just enjoy the (as always) nice pics and move on... i can appreciate someone constantly trying to improve the small details, unfortunately he picked a car that's pretty much already had the small details completely optimized... and also as always this latest mod won't include any relevant real world testing to know if any difference was made
also if anything this might reduce fuel economy since if the intake air is actually cooler more fuel can be burned, i've seen someone put a 'hot air intake' on their honda insight which improved mpgs
just enjoy the (as always) nice pics and move on...
also as always this latest mod won't include any relevant real world testing to know if any difference was made
I also enjoy the pics, just in case I'll ever be that far into a project where I would need to see something specific I would look at "YODA'S PICS"
And again, I also, sit and wait to hear of any documented improvements and they never come....not that I would do any of these "mods" anyway cuz, for 95% of us, they'd be a waste of time.
But hey YODA "Thanks for all the pics" 📸 and if you're having fun doing it, and ya have the time, then more power to ya. 👍
I also enjoy the pics, just in case I'll ever be that far into a project where I would need to see something specific I would look at "YODA'S PICS"
And again, I also, sit and wait to hear of any documented improvements and they never come....not that I would do any of these "mods" anyway cuz, for 95% of us, they'd be a waste of time.
But hey YODA "Thanks for all the pics" 📸 and if you're having fun doing it, and ya have the time, then more power to ya. 👍
Here: Read the article in the link provided in this post.
Should you agree with the before/after dyno results on the Corvette's plastic intake (which many argue plastic does not experience heat soak) then you have this post to demonstrate the material can be applied to the bottom of our Aluminum intake manifolds.
THEN, you can be first to expend money to post before/after dyno testing and have those that dispute your dyno test results.
When ready will post thermal readings.
Graph depicts information on torque increase % vs air temperatur drop courtesy of David Vizard. (If unfamiliar, Google his name)
Meanwhile, looking forward to forum project posts from forum membership not relating to trouble-shooting.
That's all fine and well but, that's a Corvette, this is a Lexus. If I had a Vette then yes, I would want more horsepower and maybe take half the engine apart to get it. But we're driving a Lexus and want to just relax when driving it, not race. I'd say the LS400 has enough power for most of it's owners. I don't disagree with the heat shield giving a tiny bit more power but I don't see any proof of how much power that would give our cars. 5 HP or 50 HP????? Is it worth the time and effort to maybe get more power?? Not for me. But I still like your pics.
Then dyno your car? I can throw a $350 Russian reflashed ECU in mine and go from 235-245 WHP to the 270-290 range no other changes. You should see over 300 with everything you did even slightly helping as claimed
always hard to try and improve on the OE engineer's designs which are likely more stringent that what we can imagine.
they have assembly/tooling and mass production considerations to contend with so they do their best with their budgets.
small improvements and nits like yoda here is welcomed, and rather insightful that a guy takes his time to improve as much as he can from the OE design.
the main audience just isn't here for that sorta thing...
small improvements and nits like yoda here is welcomed, and rather insightful that a guy takes his time to improve as much as he can from the OE design.
the main audience just isn't here for that sorta thing...
nobody's against small improvements, but these 'improvements' are never backed up with any real world testing, and any skepticism gets responded with "look at david vizard's chart"
charts by the way that are from his book on tuning holley carburetors... not what is possibly the most thoroughly engineered car of all time with variable valve timing, variable intake geometry, extremely precise manufacturing, and a complex ecu designed to only handle very specific parameters
nobody's against small improvements, but these 'improvements' are never backed up with any real world testing, and any skepticism gets responded with "look at david vizard's chart"
charts by the way that are from his book on tuning holley carburetors... not what is possibly the most thoroughly engineered car of all time with variable valve timing, variable intake geometry, extremely precise manufacturing, and a complex ecu designed to only handle very specific parameters
The last bit you said is the real issue. Modern ECUs want to meet certain targets and will do everything they can to do so.
Two "knock sensors" interface with the ECU to retard/advance the timing and enrich/lean the fuel mixture.
"Premium fuel only" (91+ octane) is recommended by the manufacturer.
When ECU determines via knock sensors that lower octane fuel (87 octane) is used, then the ignition timing will not advance fully.
To prevent engine damage, the ECU will further enrichen the fuel mixture.
This results in lower engine power and lower miles per gallon.
Numerous posts on ClublexClublexus forums on reduced MPG and lower power using 87 octane.
Heat is a contributing factor to engine knock.
So in part, a cooler intake charge will help alleviate knock or ping and allow the ECU to advance the ignition and lean the fuel mixture.
The stock ECU can adjusts ignition timing advance/retard and fuel lean/enrichment to meet conditions.
The ECU will never exceed its goal of timing advance and fuel mix no matter how much you change things. The sensors are there so that if fuel doesn't allow the goal to be met the car can see that and back off and try and advance up as far to its goal that it can.
Unless you reprogram it you are only making it easier to hit a goal the engineers already were able to hit under SAE engine verification testing.
In the simplest terms the ECU wants to see 290hp and to never exceed its emissions targets, anything past that power target it will never pursue.
The ECU will never exceed its goal of timing advance and fuel mix no matter how much you change things. The sensors are there so that if fuel doesn't allow the goal to be met the car can see that and back off and try and advance up as far to its goal that it can.
Unless you reprogram it you are only making it easier to hit a goal the engineers already were able to hit under SAE engine verification testing.
In the simplest terms the ECU wants to see 290hp and to never exceed its emissions targets, anything past that power target it will never pursue.
How do you account for 25 rear wheel horsepower gain on dyno using PPE headers? (At 6,000 RPM...low end torque suffers)
My Extrude Hone post with before/after dyno runs depictis 20 HP and 25 ft/lbs increase
How do you account for 25 rear wheel horsepower gain on dyno using PPE headers? (At 6,000 RPM...low end torque suffers)
My Extrude Hone post with before/after/after dyno runs depictis 20 HP and 25 ft/lbs increase
What was your dyno number again? I believe the number you gave was the exact same as a stock car, plus as I have explained to you before the computer wants to see preset fuel mixtures and can trip up or down 15-25% before triggering a code so that is all you have to play with on the fuel side and the timing target still will not change. Everything you have done so far will be eclipsed easily from me simply paying $350 for a re-flash to allow my engine to go to maximum possible advance emissions be damned that the knock sensors allow instead of stopping at the power/emissions limit. All you are doing with a stock tune is leveraging the fuel trim margin, and as you said low end TQ suffers and that should never be the case with headers and is NOT when the engine is tuned for it.
What was your dyno number again? I believe the number you gave was the exact same as a stock car, plus as I have explained to you before the computer wants to see preset fuel mixtures and can trip up or down 15-25% before triggering a code so that is all you have to play with on the fuel side and the timing target still will not change. Everything you have done so far will be eclipsed easily from me simply paying $350 for a re-flash to allow my engine to go to maximum possible advance emissions be damned that the knock sensors allow instead of stopping at the power/emissions limit. All you are doing with a stock tune is leveraging the fuel trim margin, and as you said low end TQ suffers and that should never be the case with headers and is NOT when the engine is tuned for it.
The Corvette has an OEM ECU...and before/after dyno results suggest increased power from a simple thermal barrier
The extrude hone project also posted before and after dyno results...unfortunately torque and H.P. increases do not agree with everyone's thinking.
Feel free to develop and post particulars of your reflash project.
04-26-20, 10:55 AM
Increasing horsepower using thermal barrier under intake manifold
