If only my wife were so in tune! Thanks!

Lmao

I go back and forth on this. I had an 80mm on my Supra for a few months last year and it was nostalgically fun. My kid referred to the car as a "roller coaster" because there was soo much build up to it coming online and making power! I'm now back to a 7275 and it's much more responsive. I don't know that I would complain about a little smaller turbo but than again, lag is part of the Supra's character. Thanks

@@jaymeagher1510 i am NOT a lag person, i want instant spool and power and i am NOT a top end hwy fan either. My 240sx is instant spool and jnstant power ... My Genesis coupe is the same way, hit the gas and it goes .. My 98 Supra is still on stock twins and they responded descent when it was stock but now with the full exhaust, no cats, and no clutch fan drag, they respond MUCH faster ... If and when i decide to remove the stock twins, i may stick with a mid size turbo to maintain the quick low end spool, because when i hit that gas pedal, i want it to respond then and there ...

@@ACommenterOnKZfaq If you decide to go single on the Supra I'd suggest a 6466 with a 1.0 housing. It's really a hard combination to beat and will enough airflow to make over 900whp without drama with supporting mods. You won't have the power you have now at 2,700-2,800rpm but it will more than make up for it once it's online. Thanks

@@jaymeagher1510 i think that 1 ar is going to me too big for my taste especially when the stock twins kick on almost instant and still give me good mid range. I can care less about top end as i dont do hwy pulls ever, most of my power pulls are going to be from a stop light launch or over taking someone from a ~45 mph stroll up to ~80mph ... So i will need something to mimic the stock twins quick response ...

Anyone who suggests a twin-scroll setup will say transient response is the main benefit though

@@BrettObie oh I see! well I hear less of that word actually but that could mostly be because all the ones I know are too busy in “drag” not the clothing though lol

We're about to jump into some SR20 builds for the engine dyno so stick around! Thanks

@@jaymeagher1510 legend 🫶🏾

@@carllourenznaidoo2470 At least on the internet! 🤙 thanks for the kind words!

You can calculate centimeter squared to A/R ..For example an A/R of 0.89 is 12 cm squared....

Because holsets are for diesels would they require a naturally larger turbine to perform as well as a precision or garret equivalent? If I used an 8cm housing would it spool as quickly as it should or would it need to be 14cm because holsets are designed on diesels like that

We're working on it! Thanks

As wheel size (MASS) increases the turbos loose transient response. A larger wheel with a smaller housing isn't ideal. It's about a balanced approach and then operating the system at a desirable pressure ratio. Ideally you want to make the power you'd like while having less pressure in the exhaust side of the engine than the inlet side. Thanks

Easy: Always go with the bigger option. 👍🏻

Bigger waste gate if the waste gate is too small it can't control boost.

If you have creep, yes a bigger wastegate will help control boost, but my experience has shown a larger housing is the better option. If you have a reasonable turbo/wastegate setup, and are still experiencing creep, a larger turbine housing may give you a nice bump in power without much if any loss in response, plus control of the boost.

So the turbine doesn't exit the down pipe at 100000rpms and kill someone in case of a failure.

This was an excellent addition to the comments section and you saved me a lot of time typing lol. Good stuff.

There is not a 40% increase on exhaust mass with the use of alcohol fuels at all. The whole 14.7:1 or 9.7:1 etc stoichiometric ratios of fuel are a hint to this. By far the majority of the exhaust mass comes from the air that's going in, even with methanol fuel. E85 is going to be far closer to around 3% more mass flow, and this arms you with choices in regards to how you want to make power. Going to E85 on a knock limited setup can often gain a lot more than 3% more power with the same airflow so the power gains you get are significantly more than the increase in exhaust mass flow would suggest. If you happen to be pushing the turbo hard enough that 3% more mass flow means EMAP is bad enough that the housing is too small you often can decide whether you want the extra response and reliability offered with E85 and just adjust boost targeting to sacrifice a bit of the power gains to bring EMAP back into check, or go up a housing size and really go for the moon. I personally have not seen a bigger housing being necessary purely from going E85, it's been more where you can go boost wise meaning a lot more flow capacity is required when you can push the turbo much harder where tuning was stopped on pump gas due to octane reasons.

@misterlith I must have glossed over that number in his comment, because you are definitely correct on that. It's definitely more with ethanol or methanol, but not much more.

​@@misterlith Nonsense. E85, for example, has a density of 773kg/m3. Gasoline is 716kg/m3 , Ethanol 100% is 784 kg/m3 and Methanol 792 kg/m3. E85 is ~8% more dense than Gasoline, right off the bat, so that throws your 3% theory on these 2 facts alone. -1. The chemical reaction that takes place in the combustion chamber is based on a fuel mass flow, primarily. Gasoline - to completely burn 1kg of gasoline in a perfect molecular reaction, you need 14.7kg of air. Ethanol E85 - 1KG of E85 9.7kg of air is required. The power output is much less than Gasoline if you're just burning at stoich. To burn the same 14.7kg of air, you need 34% more ethanol fuel by weight. This where the extra mass flow comes from. -1. using methanol, Stoich is 6.5:1 - you need 56% more Methanol Weight to burn 14.7kg of air. Thus approx. 34% more fuel is required than gasoline to burn the same quantity of air compared to that of gasoline. Because we are injecting such a large amount of ethanol to reach Lambda 1 in this case, more molecules exist in the combustion chamber, compared to that of gasoline, by weight and thus mass flow increase over that of gasoline. That is why a 2JZ will pickup approx. 400-700 more RPM spool response and hit boost earlier on a 2JZ with just Ethanol E85 vs Gasoline 93 or Petrol 98 on the same housing. It will also choke a smaller housing and increase EMAP sooner at lower boost levels, compared to Gasoline. This is why a housing increase may be recommended depending on the power goals. To put it simply, E85 has less thermal energy per kg (which is why it burns cooler) and because such a greater volume of E85 is required to burn the same quantity of air, compared to gasoline, that's where you get a much higher energy output compared to gasoline. If you have actually tuned a car, you need approx. 35-40% more injector flow / pulse width to reach the same Lambda level as Petrol/Gasoline in a performance application with headroom. That's why you need to upgrade the injectors and fuel pumps when running E85 or E100 by a considerable amount to flow more. Fuel consumption is down by approx. 40% as well compared to gasoline. You'll be lucky to get 200-250km/s to a tank in a JZA80 supra with spirited street driving, vs 400kms on gasoline. I have witnessed this in my own cars, side by side, same routes and turbo setup, different fuels, same races. This doesn't take into consideration any timing advantages that you gain from running E85, where you can easily tune up to and beyond MBT to increase the combustion pressure and thus exhaust gas velocity, compared to petrol, which further aids in a mass flow increase. -1 point to you again. All of these are needed in a quantities far more than 3% mass flow. You're way out by a factor of 10. Please humor me how you got to 3%, which cars you have tuned and how much your fuel map has changed between Petrol and E85. Then tell me why everyone that goes E85 runs 50% lager injectors and pump flow as a mere necessity to run E85 at high performance levels. when your claimed 3% will do the same job with no upgrades. Hint - it doesn't. -100. In Australia we had locally built Flex Fuel cars that ran on E85 and Petrol 98, namely the LS based SS commodore, et al. On my dyno with an OTR and exhaust it made 275rwkw Stock on Petrol. With E85 - it made the same power - it was tuned not to take advantage of e85 at all - just to run it as an alternative and then cheaper fuel available the the pump. When E85 was cheaper than Petrol - it was a good deal - you could get E85 for 20-30c per liter less than Petrol. However the fuel consumption of E85 used 25-30% more fuel according to the customers. When E85 got more expensive - it wasn't worth losing the range per tank compared to that of gasoline. If you want to make the same power as a gasoline engine - you need to burn more ethanol to do so, and thus increase the exhaust mass flow in the process. In addition the benefits of the extra fuel is better cylinder cooling, higher octane to push more timing and better boost response as the mass flow is increased earlier on, spooling the turbo sooner and improving volumetric efficiency. When you're talking 7-9 second cars - it's all about exhaust mass flow not choking the turbo to the point where high EMAPs and EGTs are a hindrance. This is why most turbo drag cars have a larger turbine inducer than compressor inducer and that's evident in the precision nomenclature. PTE 7576 / 8385 / Promod 98-103. Thus I'm not convinced by your 3%. I haven't seen it in real life on basic fuel consumption, it doesn't math out and I don't believe you have tuned a vehicle for flex fuel, as you would know that by virtue of a fuel temp vs ethanol % there's different densities that are required for the VE calculation as well as a fuel composition scaler that is based on the stoich differences at each ethanol % , to start with. -9k. There is a considerable increase in exhaust mass flow, in the the order of 30-40% depending on how rich you run your mixtures and what blend, which is responsible for the spool increase and response when using E85 vs Gasoline and can create choking issues when EMAP rises beyond an acceptable level, thus you must increase your housing size. This was done with a customer car that went from 1.01 A/R to 1.21 and gained nearly 6mph on the 1/4 mile, chopped 0.3s off the time and could run more boost before the EMAP became a limiting factor again. I don't see this 3% increase approximation to exhaust mass flow mathematically on all the chemical equations or physically in the real world. It's false. Your math is backwards based on the stoich values which means you're not qualified to even understand combustion and how an engine makes power. The more fuel weight you can burn per unit quantity of air, the more thermal energy will be released from the chemical reaction and thus the more power there is to be gained. This is the premise you don't understand and that's why you're categorically wrong.

@@racetunecalm down bud, I didn't mean offense. I enjoy learning and I've done a lot, so am also into sharing what I've learned so far and figure there is no harm in one or the other of us being wrong here. We don't agree, we clearly want to share knowledge, so this is an opportunity do suss out where things aren't adding up and both feeling like we've got something from the convo. If we push ego aside one of us will realise what we've missed, I don't feel compelled to try and willy wave about what I've done in the past to try and gain credibility and you shouldn't need to as well. The concepts we are discussing should be the truth of the matter so let's find that truth. Firstly, because I assumed you understood the fundamentals and had just missed something I didn't go max effort breaking down everything to precision or treating you like a child so my numbers were and will be loose. I'm trying to help people understand stuff, not prove how big a nerd dick I have. So here is how I came to my loose numbers. For this I'll keep it simple and say I'm going to compare two cars running .78lambda, same air mass, and that petrol stoich is 14.7:1 and E85 is 9.8. With that I'm gonna say the equivalence ratios we are working with are: Petrol: 1 / (.78 * 14.7) = 0.0872 E85: 1 / (.78 * 9.8) = 0.1308 Any further calculation on top of that for the "fuel" share of the mass going through the engine is pretty academic as air/fuel ratios are discussing the air and fuel mass ratio - I don't need to go into fuel density or anything because we are assuming that has been worked out earlier on and we are hitting our target mass ratios. What does need to be added here is the air mass, seeing as I used "1" as the reference point for mass ratios I can just go 1.0872 (adding 1 for the air mass involved in this combustion) for petrol and 1.1308 for the E85 combustion. So, those are the relative masses of air and fuel that will be going through the engine during combustion, the only way either of them change is if someone adds or removes some of it somewhere along the line. So as long as some strange shenanigans aren't afoot we should be able to go 1.1308 / 1.0872 = 1.040. So, admittedly my thumb suck of "around 3%" was looser then I expected... Unless I missed something in that there is actually 4% more exhaust mass flow with E85 vs petrol, I was wrong on that part (or just relied a bit too much on the accuracy of my thumb suck maths haha. Trust me I am more pedantic when tuning than I am when walking with my cellphone). But yeah, that's the gist of where I was coming from. Let me know if there is a glaring step I missed in the above

Prolly, buuut u just said u like top end power. Get the .82 you will definitely have power where the k series likes to make power vs the .63. K series have alot of headflow, so the .63 would just hold you back.

That depends on the brand. We have the major brands within reach. Thanks

@@jaymeagher1510 precision 6266 t4

@@ohhman9400 That's easy, call Real St. Depending on how long the turbo's been in service you may struggle to remove the housing. If it's been a couple years I'd remove the turbo off the car and place it on a bench EX housing down. Soak the hardware with PB blaster overnight. From there it's just working the hardware out and using a rubber mallet to break the housing free of the turbo's heat shield. Thanks

You just lose efficiency as the exhaust is trapped in the system. Remember it's just an air pump. The wastegate is there trying to maintain a user prescribed manifold pressure value. Thanks

I went back and forth on the terminology and assumed someone would chime in. When you look up calculating the area of odd shapes it seemed like aspect ratio was the right word. We also have to face that some brands don't account for the divider in "twin scroll" housings so we get what you mentioned with larger numerical values just to get back to the same place a "1.0" housing would be. Thanks for your feedback!

In the examples I've been around we've just stuck to the same approach. I had a 2jz with twin 6466 and .82 housings and it was making good boost by 6,000 and ran extremely well. On the Coyote engines it's the same routine, we're running close to 1.0 and they spool and perform very well. I'd venture to say the guys that have been immersed in the R35 community can chime in. It really comes down to the powerlevel and the pressure ratio that's required to make it. If you can keep the back pressure down the engines are less knock prone and live longer.

@@jaymeagher1510Thanks Uncle Jay. 👍 I'm using two T25 flanged GT2860RS turbos with .86 A/R on a 1JZ, so the goal was power (600hp-700hp using 108RON Unleaded jungle juice) but more importantly, response across a wide rpm range. The build has been catered for response and building boost as soon as possible, hence the small turbos and using not as wild cams (264s) to keep that response. 😎

I’m Looking to run a garrett style “pulsar” turbo like a g35 or gtx35 and don’t want to order the wrong stuff 😅

Big altima energy!

Except for they do, Garrett offers split Vband setups

I've also seen late model Ferrari's with split round housings. They're effective at low engine speeds. Thanks

I prefaced with the OEM approach where twin scroll has the largest impact. The aftermarket is muddy at best on the subject. I'm not saying there's "nothing to be gained" but will take the position that there's way more opinions surrounding the subject than data. Thanks

You can do that easily with the factory turbos on a 2JZ-GTE and have better response than 90% of aftermarket turbos. Just exhaust, intercooler and boost rise and voila.

@@MafiaboysWorld Oh I know the USDM twins could but that is not at all what is available to me, its NA

@@streetinfamy GE head peasant. 😛🤣 To be honest, a G25-660 might be your best option there. Available as T25 flange or V-band. 👍 As Jay said, lower A/R means better response but the turbo itself will choke out at higher rpm. Also factor in manifold runner sizing for this as that can also affect how the turbo absorbs the exhaust gases to turn in the first place. 👍

@@MafiaboysWorld aye, it's a hard life, the life of a pirate, yeah ive looked into those $$$$, there is the option to swap a 1JZGTE head on since the 1J block froze but man what a hassle after finally getting the NA going... thanks for the scoop

@@streetinfamy in reality, both heads are awesome. Some argue the GE is better than the GTE. I totally agree that the GE is much better than the SMALL PORT vvt-i versions of the 1JZ/2JZ but the BIG PORT Non-VVTI? Hell no and I'll die on this hill fighting anyone over it! 😂👍

Nah the Barra mate

Got to disagree with cross plane cannot be the best ever, it's just not engineered that well. Best cheap engine maybe but anything better balanced is nicer IMO

Only for V8s.

Incredibly subjective but okay.

Better at parasitic power loss sure. Trash in every other possible way

Really though I like my k20s with NOS and any 2jz or RB's get supercharged and any V8 loke the coyote or ls gets the N/A treatment. Turbos run too hot.

@@marcscarthingsandstuff then you're doing it wrong