Anyone close to 300hp on IUZFE motor with stock internals?

[MWP]

The 1UZ engine by design is limited by its cams.
The stock cams are what creates the engines legendary smoothness, but limits the engines power (compared to other engines of similar capacity).
If you are after decent NA power gains, cams are a must!

This is why the 1UZ won the engine of the year title again after VVTI was added.
The VVTI system allowed the smoothness of the engine at low power to be maintained, but changes cam profile at the top end for power.

Download the Engine Analyzer Pro software and have play with the engine files i made up.
Try using some different cam profiles and open up the intake and exst a bit, youll see what improvements are to be had.

 

[jibbby]

Kelford cams deliver 45 ore horsepower on these engines according to what the owner told me via emails...

MVP your 100% right....

 

[platinum0921]

Is that 45hp properly tuned or just on stock ecu? And which ones were you referring to?

 

[jibbby]

The kelford cams application was for a 1992 Sc400 running nos...The owner said to me that 45 hp should be expected at higher rpms... I honestly forgot the numbered name as inquired about these cams about a year ago....Too pricey for me, so I passed....

I would assume fine tuning would be needed to achieve those gains but not sure? Never bothered to ask.. If your a paid member on this forum research the cam threads and you will find what you are looking for...Or contact Kelford Cams via emails....That is what I did...

 

[jibbby]

If you mean 300rwhp, then absolutely no chance.
There is no way the stock cams will flow those numbers.

If you mean 300hp @ the flywheel, then yes.
I have dynoed 240rwhp, and I know others that have dyno'd between the 230-240rwhp mark.

I am hoping to break over 250rwhp when I go back there in a month or so, and then hopefully back this up with some times at the strip.

What is needed to get this?
The stock LS400 headers will do it. SC400 headers would need to be changed though.
Revised intake system is needed.
Revised exhaust from the headers back.
Remap ecu, either via a piggyback that does ignition and fuel, or a complete stand alone.
The stock auto should be fine.

300flyhp = ~240rwhp with manual @ ~20% drivetrain losses
or
300flyhp = ~225rwhp with auto @ ~25% drivetrain losses

Peewee. I know this post of yours is about as old as my Lexus but I don't think those mods will ever make the 225rwhp you are claiming...Atleast it won't in my SC400, I see maybe 215rwhp tops... I don't see how anyone can get over 220rwhp with out cams or that eight throttle body intake...Maybe with Headers and also 3" side exhaust no mufflers, Cold air intake, stand alone ECU, Hydo pump deletion, top notch electrical, and outstanding compression in each cylinder maybe then 225rwhp..... Do you guys agree? This in regards to the first year 1UZ-FE 4.0 liter V8 motors...

 

[Anish Varsani]

Transmission loss is normally between 30-35%. Manuals will be 1-2% less lossy as auto's have the oil pump to drive.

I pulled 213rwhp so that'd be 304-328fwhp. Mods were headers and a fuel trim.

 

[Peewee]

30-35% ??

No way is it that much. Maybe for an auto from the 70's.
20-25% is more like the accepted figure.

 

[neal]

a friend of mine had his car put on new dyno and I think the figures were 280hp at the wheels and the dyno calculated crank hp at 310. thats a stock 1uz with hand made exhaust and indivual throttle bodies, links cpu and a lot of tuning. I will ask him for a copy of dyno sheet

 

[Anish Varsani]

Soarers with about 70 000km on them must be suffering significant power loss since new if the loss is only 20-25%.

Stock soarers should be putting 156kw on the back wheels instead on 120-130kW as is typically seen on dyno days.

 

[Anish Varsani]

Ok, I stand corrected. The power figure claimed by manufacturers dosn't include driving accessories. I don't think the SAE test method takes into account water pumps and oil pumps either.

 

[Peewee]

As the o2 sensors get old the car will start running richer and richer.
This will hurt power.

191kW at the fly (I think this is what the soarer was rated at?)
Given a 25% drivetrain loss -> 48kW lost.
That leaves 143rwkW assuming the motor is still in its peak.

Take 5-10rwkw out for aging, and you are left with around 137rwkW, which is a pretty common figure to see at a dyno day.

As far as I know from the mid 80's onwards motor power was rated with all the accessories connected, but I'm not sure whether the exhaust or intake is identical to what is in the car.

 

[platinum0921]

We have about 26.5% drivetrain power loss. So 200rwhp is about 272hp at the flywheel. I think a manual swap would drop that to under 20%. I think Neil got like 20kw from the manual swap.

 

[jibbby]

New at stock looking at my manual....Lexux rates the SC400/Soarer new at 186whp and 250hp at the crank....I don't have a calculator next to me so there is your stock new drivetrain loss right there... 25% DT loss sounds about right to me....I would assume that percentage number can be reduced with lighter weight alluminum or CF shafts, light weight racing rims/tires etc...

Anish -213whp is very good for just fuel tuning and headers...The question I have is how accurate and consistant are all dyno machines? I would imagine each machine and setup is slightly different...Is that assumption correct?...Conditions vary, roller resistance may vary... Some Dyno shops run stronger fans then others in front of the cars at dyno's...I think there are some factors to consider, no?

 

[UZZ30-Québec]

Judging by the times a SC400 1st gen (10:1) does on the 1/4 mile, there's no way this engine has 250HP. a car that can't make more than 15.4 on the 1/4 mile... I do beleive the auto trans and weight of the car decrease the times but man... 15.4!

If later 10.4:1 does 15.2 with 250HP. I barely beleive it has 250HP. It probably has it, but no way the 1UZ push more than that on stock trims.

the new rav4 with 268HP and auto trans do 14.9 on the 1/4 mile!!! and it's a Rav4!!!!

 

[WDoherty]

i know, sad huh. I guess if any rav4's revs their engines i'll back off.

 

[WDoherty]

Judging by the times a SC400 1st gen (10:1) does on the 1/4 mile, there's no way this engine has 250HP. a car that can't make more than 15.4 on the 1/4 mile... I do beleive the auto trans and weight of the car decrease the times but man... 15.4!

If later 10.4:1 does 15.2 with 250HP. I barely beleive it has 250HP. It probably has it, but no way the 1UZ push more than that on stock trims.

the new rav4 with 268HP and auto trans do 14.9 on the 1/4 mile!!! and it's a Rav4!!!!

yeah i think intellexual said the 1uz with 10.4 does 15.2 vs. 15.4. I thought you had the 10.4 motor but i just found out that the sc didn't get it until 96, so i believe you still have the 10:1 motor. What did you end up running?

 

[UZZ30-Québec]

How can i tell i have the 10.4 motor?

Mine is a Late '95 model. don't know exactly wich month.

I did 15.4 @93MPH with approx 3800lbs in the car. 185 000km, bone stock except K&N air filter cartridge (fit in stock airbox) but this is not really a mod... well, i don't count 1/2 HP mods "mod"!

I think with cheaper tires to break traction, more practice and reduced weight (all additional insulation plus sound system) and couple of useless stuff removed (spare) i could make it to 15.2

 

[UZZ30-Québec]

ohh, I also forgot the new Rav4's HP is calculated with the new SAE norms.

maybe back in 1995 those 268HP would be 280?

 

[Philly#1 Lex]

umh, I don think you can compare the rav 4 and the SC400 by just looking the 1/4 mile times. 1/4 mile times come down to more than just hp. The new Rav 4 has atleast a new 5 or 6 spd tranny with is a hell of alot better than the early 1uz 4 spd tranny which is a dog as we all know. I think that the engine are not underrated from the factory just the tranny was made with si much "luxury & smooth shifting in mind" that it takes more than normal 20-25% drivetrain loss. Crap if you put a high stall 2800 rpm TC in the early ones which a good launch and posi u could get in the 14's easy. (High 14's) Early 1UZ had a couple of defects from the factory in my opinion and if you where to open them up The V8 would be alot more popular in my opinion.

First is that stupid 4 spd auto: Fix is 5sp manual (or 5sp newer trannies, good luck fitting that)

Darn smart behind ECU: Couple of fixes but are usually pricey and are uncharted water (i.e. AEM or similar, toyota's ecu seem to be to smart for piggyback)

and Cams! I know the 1UZ can rev higher and have a better power band so that it can run better with modern sports cars.

My opinions. And I think these are the keys to unlocking the 1UZ. Forced induction works but these three always hold the motor back. What do you guys think, Are my opinions justified:shrug:

 

[stevechumo]

.....the new rav4 with 268HP and auto trans do 14.9 on the 1/4 mile!!! and it's a Rav4!!!!

Oops! From now on, I'll have to watch out for the new Toyota Rav 4. For a very long time, I always look down on the older ones (I don't know how the new one looks like). If I offend anyone, please don't mind my opinion. The things that I don't like about it is its sissy look, weak power, tight space. I rather go for a sedan or a real SUV (mid-size is ok) instead of a Rav 4 or a Honda CRV.