Takeda Intake And H&s Exhaust Update...

[Stuno1]

They certainly can. Will be more noise as well! :)

[Stuno1]

They can also install a valve so you have noisy and quiet setting.

[Peter P18]

They can also install a valve so you have noisy and quiet setting.

Ummm, nah! Noisy will be just fine! ;)

As we discussed, can always add a muffler if it's too much. :)

[noby76]

Hey dude, glad to see you've got a dual setup, though it looks like the secondary cats are still in place, these can be seen on the right hand side of the screen at about 17 seconds. Still, you should see a small gain...

As for saying it's going to lose power, that's the most ridiculous thing I've heard. Are you saying this from personal experience or just repeating the ye olde myth 'ooh, you'll lose back pressure and power'?

Back pressure is not a good thing, an ideal exhaust would have none. What it does need is to maintain gas velocity, which then, like syphoning, draws exhaust gas out of the cylinder, allowing a greater air/fuel mixture to be burnt on the next cycle. Too large a diameter exhaust, on a normally aspirated engine, will reduce gas velocity and low end power, but we know the ideal size for exhausts these days. For example, a 2L-2.5L engine would ideally want a 2.25inch-2.5inch exhaust. The ISF is a 5L V8, so dual 2.25inch-2.5 inch exhausts are perfect.

On a turbocharged car, it is almost a case of the larger diameter the better, as the exhaust wheel on the turbo requires the pressure difference to operate.

Neil

not sure if you read my post well but i dont think i said the C43 lost power infact it made 14bhp over stock but the dude was a bit confused as to why his low to mid performance was compromised slightly after the mods. i guess every car behaves differently after performance parts have been fitted.

attached is a before (blue) and after (green) comparison of Joe Z + Intake against Lexus stock intake + exhaust curtosey of clublexus.com concentrating on only the blue and green upper lines we notice from about 2400rpm till about 3500rpm both the blue and green lines are somewhat close to each other through the rpm range with slightly minor gap between them. come 3700 they almost touch but soon after the green line opens the gap between the blue till about 4250rpm where the gap starts to close up again between the two but come around 4600rpm the green line starts to open its gap against the blue all the way till they both fall off at 6600rpm.

conclusion from this dyno graph confirms although the intake + exhaust mod (green) did have the upper hand, the stock intake + exhaust (blue) was quite close to it all the way from 2400rpm till about 4600rpm which concludes intake exhaust mod comes alive at the last 2000rpm. which yeilded the dud around 26rwhp. was it a gain over stock yes it was but not a lot to be felt on the road/track once you work it out in terms of power to weight ratio but its still a gain. + the awesome sound which comes with it.

http://www.clublexus.com/forums/is-f/406273-joez-exhaust-intake-dyno-26-rwhp-19-rwtq-sae-2.html

[Peter P18]

Not to rain on anyone's parade, but dyno's aren't a true representation of a cars 'real' world capabilities. The conditions are simulated, and not something anyone should be hanging their hat on in terms of accuracy. Does the intake and exhaust improve the performance? Yes it does.

As I think every single ISF owner that attended the Bluewater meet last weekend would agree, Stu's car sounds awesome. :)

Has he lost power by fitting the exhaust and intake, I seriously doubt it.

The US guys run 95 RON fuel I believe? Know from the Supra side of things that they are massively de-tuned, due to the poor quality of fuel over there.

Whilst I'm not 100% sure if the OEM ISF ECU adjusts for fuel quality, the dyno operator may back off early if he thinks the car is at risk of detonation. This would occur much quicker on a car running lower quality fuel.

Hopefully the dyno day will give us some numbers to study, but it's not just about HP gains. The main reason for the exhaust is to replace those crappy fake tips, and give it the true V8 burble it deserves.

[noby76]

Not to rain on anyone's parade, but dyno's aren't a true representation of a cars 'real' world capabilities. The conditions are simulated, and not something anyone should be hanging their hat on in terms of accuracy. Does the intake and exhaust improve the performance? Yes it does.

yeh i agree on that one but dyno's are there to give and 'indication' of a cars performance characteristics and also to help engineers tune a car in terms of the direction they want to take it so its still very important tool to have when tunning/mapping an engine.

[Stuno1]

It will certainly be interesting to see dyno results against stock and if the power is the same or down or improved im good. I'm more I intrigued than bothered if im honest.

Good conversation though.

Stu

[Cable]

Hey dude, glad to see you've got a dual setup, though it looks like the secondary cats are still in place, these can be seen on the right hand side of the screen at about 17 seconds. Still, you should see a small gain...

As for saying it's going to lose power, that's the most ridiculous thing I've heard. Are you saying this from personal experience or just repeating the ye olde myth 'ooh, you'll lose back pressure and power'?

Back pressure is not a good thing, an ideal exhaust would have none. What it does need is to maintain gas velocity, which then, like syphoning, draws exhaust gas out of the cylinder, allowing a greater air/fuel mixture to be burnt on the next cycle. Too large a diameter exhaust, on a normally aspirated engine, will reduce gas velocity and low end power, but we know the ideal size for exhausts these days. For example, a 2L-2.5L engine would ideally want a 2.25inch-2.5inch exhaust. The ISF is a 5L V8, so dual 2.25inch-2.5 inch exhausts are perfect.

On a turbocharged car, it is almost a case of the larger diameter the better, as the exhaust wheel on the turbo requires the pressure difference to operate.

Neil

not sure if you read my post well but i dont think i said the C43 lost power infact it made 14bhp over stock but the dude was a bit confused as to why his low to mid performance was compromised slightly after the mods. i guess every car behaves differently after performance parts have been fitted.

attached is a before (blue) and after (green) comparison of Joe Z + Intake against Lexus stock intake + exhaust curtosey of clublexus.com concentrating on only the blue and green upper lines we notice from about 2400rpm till about 3500rpm both the blue and green lines are somewhat close to each other through the rpm range with slightly minor gap between them. come 3700 they almost touch but soon after the green line opens the gap between the blue till about 4250rpm where the gap starts to close up again between the two but come around 4600rpm the green line starts to open its gap against the blue all the way till they both fall off at 6600rpm.

conclusion from this dyno graph confirms although the intake + exhaust mod (green) did have the upper hand, the stock intake + exhaust (blue) was quite close to it all the way from 2400rpm till about 4600rpm which concludes intake exhaust mod comes alive at the last 2000rpm. which yeilded the dud around 26rwhp. was it a gain over stock yes it was but not a lot to be felt on the road/track once you work it out in terms of power to weight ratio but its still a gain. + the awesome sound which comes with it.

Dyno.jpg

http://www.clublexus.com/forums/is-f/406273-joez-exhaust-intake-dyno-26-rwhp-19-rwtq-sae-2.html

Hi John, sorry my response wasn't aimed at you; apologies if it seemed that way.

Thanks for posting this graph, just to highlight to others that a well made exhaust will make gains, over a compromised original equipment, mostly in the higher end of the rev range, where gas flow is at its greatest.

This is a 26 rwhp gain, so approximately 33 bhp gain at the flywheel. That is nothing to be sniffed at, and quite definitely 'perceptable'. Plus it rounds it up to a very healthy 450bhp ;)

Neil

[Valkirk]

This is something I will never understand, if all it takes to increase the car performance as suggested above to 450 bhp by wacking on a new intake and exhaust then why would that have not just been done on the development? The new RCF is using a highly developed version of the ISF engine pushing over 450bhp, given how much time and development they spent on that to gain that performance increase then along comes Joe Bloggs and sticks another exhaust and intake on to give it 490.....

And I can't believe there was a Bluewater meet and I missed it....totally gutted, my local shopping place as well :(

[Peter P18]

I think someone touched on this earlier on the thread, but Lexus would have set a target figure for the ISF when they built it. The engine, intake, cam, exhaust, ECU etc would have been chosen to achieve that target output. The simple fact is the engine can produce closer to 500 if you add different parts.

Yes it could alter the low and mid range figures, but it will gain in the higher range and produce more power.

I've not started digging into aftermarket ECU's yet, but if something like the SYVECS we used on the Supra will work, Ryan at 2bar tuning can re-map the car to achieve an optimum setup with all of the extra components.

Look at the GTR. it's a well known fact that no two GTR's produce the same horsepower. Some got more than others, despite having identical blocks, heads, cranks, cams etc.

Lexus also play the long game, and may have held back the ISF, so they could add power to the RCF.

Either way there are good gains to be had if you have deep enough pockets, and a desire to gain more power. Same applies to most cars, but turbo'd and supercharged cars are generally easier to do it with than n/a's.

[Peter P18]

Anyone else heard about this new rule that may become part of the MOT test? H&S said they could do me a second de-cat pipe, but they told me to check with my local MOT tester first. Apparently the rules are changing so that all cars must retain the same amount of catalytic converters they were fitted with at the factory?? Guessing that's going to be a nasty surprise for a whole heap of cars if it does come into affect! :(

Has made me hold off till I find out more.

I don't see the purpose of it as long as the emission levels pass? Surely that's all it should need to do??

[Cable]

There's been many a scare, regarding new MOT legislation, over the years, and this is a new one for me.

My immediate thoughts are how are they going to know how many cats are on a car from the factory? I don't believe this information is currently being logged; it may be something they put in place for future cars, but I seriously doubt they'd be able to do it retrospectively.

[Valkirk]

I've read a bit about it, in many ways it is a positive thing however it isn't if you happen to like modding your car.

They are bringing it in for all the modern electronic components that don't get tested. If your car has ABS but it doesn't work and the lights on in the dash then the car would still pass but after it would fail.

The drawback is adding options to your car can now actually make it harder for MOT in the future, TPS for example.

http://webarchive.nationalarchives.gov.uk/20130402174401/http://www.dft.gov.uk/vosa/repository/CHANGES%20TO%20THE%20MOT%20TEST%20EFFECTIVE%20FROM%2020%20MARCH%202013.pdf

[Valkirk]

Actually they were 2013 changes, but found this:

Exhaust emissions: Vehicle meets the requirements for exhaust emissions, dependent on the age and fuel type of the vehicle.

Exhaust system: Secure. Complete. Catalyst missing where one was fitted as standard. Without serious leaks and is not too noisy.

https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/195074/CONT071791.pdf

[Stuno1]

Pete - no idea re legislation but be intersting to hear how loud it is with our secondary cats.

I know you can buy straight through pipes designed to look like cats for the reasons above though.

Stu

[Peter P18]

Thanks guys. :)

Will probably try it without them to begin with. As long as I keep them handy in the garage, can't see it being a major issue if they do kick up come MOT time.

Where you been hiding Stu? Did you see the painted engine cover pictures I put up at the weekend? Looks a lot better than it did in the silver mate. ;)

Have a look and let me know what you think chap. Pictures are on my 'Productive Day' thread.

Cheers.

Peter :)

[Stuno1]

Ill have a butchers. Been on a stag....destroyed!

You going with H&W then? As long as they make it possible to bolt them back on (put a removable straight through pipe in their place) and dont make it all solid pipe then you are spot on.

May be fookin loud though!

Stu

[Peter P18]

Lol. Thought this place had been eerily quiet over the weekend! ;)

I did think I would get them to retain the resonator that they removed on your system, and lose the secondary cats. Hoping that will give more performance, but not change the noise levels too much.

Can't be dealing with anything too loud! :(

[Stuno1]

Good to see i was missed ;)

Wouldn't having the resenator there disrupt the good work done by removing the cats to free up the gas flow?

Also, retaining the resenator would mean you keep a 2 to 1 system and don't have a dual system.

[Peter P18]

Good point. Maybe we look at doing bigger mufflers, or add an additional one if it's too loud with the secondary cats removed??

Guessing they will come up with a plan nearer the time.

[Stuno1]

Maybe bigger back boxes, would be the easiest option if you want to get rid of cats and mid pipe muffler. Will also be less restrictive on gas flow and give you a dual system.

[Cable]

Just get a couple of small, straight through, resonators for the centre, similar to the JoeZ system, one for each side. As they're straight through, they'd be negligible gas disruption.

Pete, I had been wondering, did H&S do a 'H-Pipe' or a crossover at anypoint on your system? I couldn't make out from the video...

[Stuno1]

Just get a couple of small, straight through, resonators for the centre, similar to the JoeZ system, one for each side. As they're straight through, they'd be negligible gas disruption.

Pete, I had been wondering, did H&S do a 'H-Pipe' or a crossover at anypoint on your system? I couldn't make out from the video...

I had a dual system fella. No crossover. Desperate pipes for each side.

[CharlieC]

Hey Stu, are you going to have it dyno"d? Would like to know before I start buying bits for mine!

Cheers Rob.

[Stuno1]

I am yes. So is Pete who has takeda only and hopefully we will get a stock isf along as well. Once I get my car back I'll arrange a day or half day (depending on numbers) at a place called 'amd performance'.

Should be a good laugh.

Stu