A question of Power

[UltraViolet]

Hiya boys,

I have a question for you that have owned IS200s for a while. It comes with a 6-cylinder 2 litre engine with VVTi technology and ETCSi... yet only produces 153bhp. Now personally I cannot see how Japanese engineering can produce such an engine with so little power - so I am hoping that it has some quite simple 'restrictions' and with a small amount of tinkering, all those hidden horses can be set free. I don't mean by adding forced induction, is the engine management system being used to keep power down??? I would like to release the power without adding costly extras that are visable and risk invalidating my warrenty.

I would guess that this engine should produce at least 185bhp out of the box without even starting to work on the breathing etc.

Any findings????

[Monster-Mat]

toyota had a problem when asked to produce a 2 litre 6 cylinder engine to compete with BMW for the european market....they never had one,what they did have was an old cast iron block that was an old design so they kept costs down by producing a high tech head from alloy and plopped it on top,the engine is highly de-tuned,to keep its life up,in Japan many years ago HKS did develop the old cast block upto 200bhp,however those plans and parts are long gone,so thats why we have a low powered engine,the internals are not really designed for power more for smoothe power delivery

[UltraViolet]

Ahh I see - I still think that 153hp from a 6cyl engine is very poor even for old japanese technology. I'm sure the management system is seriously restricting the output of the engine since my boyfriend owns a 10 year old Honda Prelude which has a 2.0i 4cyl DOHC 16valve engine (non-VTEC) that produces the same power as the IS200.

Also, if the IS200 block is an old cast design doesn't this create reliabilitylongevity issues with supercharging and other big power gains ?

Does the JDM Altezza use the same engine as I've heard their version is more powerful.

[javadude]

At least it's still better than the BMW 318i which is 2 ltr 6 cyl and only 143 bhp. :D

[NotoriousREV]

Actually, the non-VTEC 2.0 Honda engine in the Prelude is 20bhp down on the Lexus engine, even the 2.3 non-VTEC motor only beats our 2 litre by 7bhp with a 300cc advantage.

The problem with the IS motor isn't so much lack of power, it's lack of torque, the engine is just too peaky for the weight of car. The 0 - 60 and 1/4 mile times are much lower than you would normally expect from a car with over 150bhp.

The JDM Altezza is fitted with a very good 2.0 turbo 4 cylinder motor, which probably wasn't deemed refined enough for a car that was intended to beat the 3 series at it's own game.

A good way to measure an engine's efficiency is to compare specific output, BHP/litre.

BMW's 320i has a Double VANOS equipped 6 cylinder 2171cc engine that makes 170bhp. Thats 78.3 bhp/litre, while our 1988cc engine makes 153bhp, which is 77bhp/litre. The average NA engine makes about 70 bhp/litre (in fact Honda's current Accord adverts boast that there 2.0 VTEC motor makes an "exceptionally high" 70 bhp/litre!).

Still, Toyota/Lexus could have done us better, the Celica 190 makes 106.7bhp/litre, thats more than a McClaren F1 or a BMW M3. If our engines made that, we'd have 212bhp before any mods :o

BTW, my bike makes 175bhp/litre ;)

[Edited on 14-1-2002 by NotoriousREV]

[lexicon]

UV,

I think the Jap Altezza uses a 4cyl 2L turbo unit.

Lexus didn't want a 4 cylinder motor in the IS's market

[Rob]

i have to agree with you about the lack of torque, takes an age to accelerate, i also find the engine reluctant to rev freely, talking about the prelude a guy at work has one and he pulled away from me no probs in a sprint!!! oh the shame of it:( but not too convinced he didnt have a few mods himself!?

cheers

robbie

[IS-PW]

Hi Guys,

The JDM Altezza uses a highly tuned n/a 4 cyl 2.0l engine with dual VVTI. No turbo.

[UltraViolet]

Let me quickly state that my question does not mean in anyway to disrespect the Lexus - don't forget I have just recently ordered one, and when it arrives, it will the the first new car I have ever bought! :)

I was just trying to ascertain if I can release the horsepower that should be there. No point comparing the Lexus engineers with BMW as Japanese engineering is renouned for better power extraction from small engines.

Hence I compared with the old 3rd gen Prelude 2.0i which is 4 cylinder DOHC which produces 150bhp. The 4th gen 2.0 is only SOHC and so produces 131bhp. I didn't compare with VTEC as I thought that this would be deemed unfair. I also chose the old Prelude (1987-1991) as the point had been made that the Lexus used an old block.

The Accord is a 4 cylinder engine producing 70bhp per litre. It starts from £13,995. The Lexus is a higher price point with a 6 cylinder engine. I think that it is not unreasonable to expect 90bhp per litre from a Japanese 6 cylinder engine with VVTi.

So back to the question...... I assume then that no-one knows how to get at the hidden horses? I am not talking the sort of gains (or change in character) that forced induction brings, I just feel that they are keeping something from us!

Anyone discussed this perhaps with Unichip???? I may speak to them.

[superchargedmorph]

Hi all, I was faced with these concerns before I supercharged, I think the engine is advanced but has been lowered in power, the car is fine with the compressor I spoke to tte and it is perfectly ok. The main point is that lexus (japan) dont like their cars played with, they tried to put a stop on superchargers at first. Becuase of this no one makes any engine upgrades for induction, chips etc. In the USA where the IS300 rules they are doing all sorts (swift racing technologies). They are getting quite a few hp from induction kits.

Hopefully this will change, some Lexus Dealers do think the supercharger should be an official add on.

[Richie]

The Altezza engine is the 3S-ge which produces 210 hp and does not have a turbo.

[lexicon]

I stand (or rather, sit) corrected

210hp is a big output for a N/A 2.0, so I just assumed it was a turbo - that'll teach me

[Richie]

I stand (or rather, sit) corrected

210hp is a big output for a N/A 2.0, so I just assumed it was a turbo - that'll teach me

LOL, that's no problem dude!!!

[NotoriousREV]

UV, comparing a 2.0 litre 4 cyl and a 2.0 litre 6 cyl engine for power wont make any difference. More cylinders doesn't always equal more power, especially in small motors where the advantages of more cylinders is negligable. For example, Mazda's Mx-3 (1.8L V6) puts out 128bhp@6500, compared to Mazda's MX-5 (1.8L I4) giving 128bhp@6500.

However, as the IS is using an old design of motor versus Honda's very up to date motor, and let's be honest, 6500rpm isn't a very impressive redline considering the pistons are tiny.

Possibly the way to go is some kind of modification to the VVTi system and raise the redline.

The exhaust system up to the back box is considered excellent amongst tuners, better than most aftermarket items, with only the back box providing any restriction.

I personally loaned my car to K&N (UK) to develop a Genration 3 57i Induction Kit. After 2 days, they gave it back saying they couldn't make a kit that worked well enough and was easily producable and fittable.

Anyone know what the standard comp ratio is for the IS?

[Wallace]

The book says 10:1, and it admitts not fitting the higher performance 3S-GE four cylinder engine was "a missed opportunity". Do we need to rename the web-site as "The could be faster and luxurious"

see "Lexus- The Challenge to create the finest automobile"...by Brian Long

[Edited on 16-1-2002 by Wallace]

[UltraViolet]

I wasn't comparing with Honda's upto date engine.... I was comparing with the 1988 old engine........ no matter, since there is no easy answer - I shall try to find out more about the car when I get it.

I'm not bad at extracting power - I have 162bhp at the wheels (circa 185-190bhp at the crank) from a 1.6 engine in my other car, and that is NA and not spending silly money or doing anything that would make the engine unreliable or lumpy........

I will let you know what I find - it will be in a few months - I'm not going nuts this side of the trackday season!!

Thanks for all the thoughts though.

[NotoriousREV]

10:1, hmm not huge scope there then ( couple of points maybe).

The torque and power peaks are pretty close together, indicating an engine thats pretty highly tuned already, although interestingly, peak power is made at the redline.

This leads me to think that any improvements in peak power would seriously impede drivability, as the sub-4500 rpm range is already very weak (I nearly got wasted by a Fiesta Zetec this morning until the VVTi woke up )

The gearing doesn't help matters, it's tall in the lower gears and short in the upper gears. 1-2 and 2-3 drop the car out of it's power band, then 4-5-6 only lose about 1000rpm total, the gears should have been better spaced.

Not fitting a better engine certainly was a missed opportunity. I love everything else about the car, but the engine is pants.

I feel lke going to Lexus and demanding they give me my mid-range back! :D

[javadude]

nearly got wasted by a Fiesta Zetec

know wot u mean - I pulled onto the motorway the other day pushing it hard through each gear and the ford focus behind stayed with me all the way. It surprised me so I looked at the figures - I guess it was a 2 litre - they do 0-60 in 9.2 sec. Yesterday I was following a Mondeo at the same place and I was struggling to keep up. Still, at least I can pass them when they break down. :D

[superchargedmorph]

well if it helps any I pis####d off a new maserati 3200 gt driver the other day when he couldn't lose me, and have been shocking plenty of bmw's and other sporty numbers!

[NotoriousREV]

I hate you. Just give me your address and I'll be round with a bag of spanners :D

[superchargedmorph]

I'm going to sleep in my car now!

[UltraViolet]

I won't be after peak power - not too bothered about numbers to quote in the pub.... midrange is where the work is needed...... If the power curve is improved but peak remains the same, won't be too disappointed - but I think we should all give feedback to Lexus that we want the next model update to include a good 2 litre engine - we want power without 15mpg and the price tag of the 3 litre!!!! (and manual shift!!!)

[NotoriousREV]

amen to that!

I know there's a device available for Honda's that let's you play with the VTEC settings. Is there anything like that for our VVTi? I have myself convinced that the VVTi is a con, and in fact it just makes a step in the power for the sake of it :D

What you wnat is the following motor:

1G-GTE DOHC 4 85-90 1988* 210@6200 203@3800 75 75 8.5:1

It takes twin-turbos to reach that kind of power. None of the 1G series has made more than 168 without forced induction. I found a couple of Toyota engine websites, and the general consensus was 1G = don't bother.

Anyone got a used 4.3 V8? :D

[Edited on 18-1-2002 by NotoriousREV]

[Random Fiesta owner]

10:1, hmm not huge scope there then ( couple of points maybe).

The torque and power peaks are pretty close together, indicating an engine thats pretty highly tuned already, although interestingly, peak power is made at the redline.

This leads me to think that any improvements in peak power would seriously impede drivability, as the sub-4500 rpm range is already very weak (I nearly got wasted by a Fiesta Zetec this morning until the VVTi woke up )

The gearing doesn't help matters, it's tall in the lower gears and short in the upper gears. 1-2 and 2-3 drop the car out of it's power band, then 4-5-6 only lose about 1000rpm total, the gears should have been better spaced.

Not fitting a better engine certainly was a missed opportunity. I love everything else about the car, but the engine is pants.

I feel lke going to Lexus and demanding they give me my mid-range back! :D

RAA!!!! :D :P

[UKPulse]

Hmmm.... my quest for more power is costing me the price of a new IS300...! ;) Sadly my dealer says the IS430 is still just a concept, otherwise I'd sell the house and buy one! :duh: