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How do you calculate how much HP a turbo will add?


calebharry

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This is a serious question!

 

If you have the 2JZ-GE it puts out around 220HP, and the 2JZ-GTE is around 280HP? How do you calculate how much more HP a turbo will add?

 

Or if you want to calculate it for me, with the right tuning, and the 3.4Ltr TMS Stage 4 block and head, how much power will you get with:

 

Single Greddy TD07S-25G

Single Greddy T78-29D

Single Greddy T78-33D

 

Then once you have those numbers, how do you calculate how much a Twin setup using the same Turbos will be? Im pretty sure its not exactly double, it will drop a bit right?

 

E.G: If you have the T78-29D putting out 650HP in a single setup, if you make a Twin setup using two of them, the total power wont be 1300HP? It will be around 1150-1200HP?

 

I am asking this because im just curious... BTW can you still have a Sequential Twin Turbo setup if your boosting over 1200HP? Or do you have to have them setup Parallel once you hit those numbers?

 

BTW if you want to answer my question, so that i can understand it, could you please set it out something like this:

 

Single TD07S-25G = 600HP

Single T78-29D = 650HP

Single T78-33D = 700HP

 

Twin TD07S-25G = 1050HP

Twin T78-29D = 1200HP

Twin T78-33D = 1350HP

(except put the real HP numbers in, mine were guesses)

Then a brief explanation of how to figure it out for future purposes :)

 

Thanks guys!

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easy calculation for this one,

 

you take the Ltr of car Supra = 3.0 multiply that by the psi you will run on that turbo, then multiply that figure again by the number of cylinders.

 

So for the Supra : 3.0 x 35psi x 6 cylinders = 630bhp

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easy calculation for this one,

 

you take the Ltr of car Supra = 3.0 multiply that by the psi you will run on that turbo, then multiply that figure again by the number of cylinders.

 

So for the Supra : 3.0 x 35psi x 6 cylinders = 630bhp

 

Sunny is right, that equations gives your answer +\- 5%

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That may give you back of fag packet estimations but there are far more variables involved to get a closer estimate.

Using those calculations a standard supra should have 198bhp (3x11x6). Which is significantly more than 5% out.

Similarly a T88 running 1.6Bar would produce 417.6bhp (3x23.2x6) using these figures.

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So you would have to run 60Psi to get around 1200HP? The calculation looks right, but i thought you needed under 40PSI to get 1000hp?

 

Pretty much i want to know how much power will i get if i have Twin T78-29D's, but i knew if i said that straight up i would of gotten a lot of 'negative' feedback, but lets see:

 

How much HP will i get if i have Sequential Twin T78-29D's, with the 3.4Ltr Titan MotorSports Stage 4 Block and head?

 

---EDIT---

 

If were talking PSI, the Trust website says that all 3 turbos i listed have a maximum Kpa of 190, which is 27.5PSI, so if i have 2, it will be 55PSI? Is that correct? Sounds a bit much :/

Edited by calebharry (see edit history)
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not sure about them figures as well that means every turbo gives you the same power regardless of size ? or am i missing something

 

anyway to answer your other question to keep the sequetial would take alot of pipe fabrication , down pipes, manifolds, intake piping , but is do able if you have the skills but would be at great cost,

a 1300hp supra will not put that power down to the floor it cant even at bpu 400bhp which is what make the supra fun

Edited by mellonman (see edit history)
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Turbos have efficiency ranges. One turbo will be good for 1.0bar, another will be good for 3.0bar. If you take a turbo that's efficient at 1.0bar and crank it up to 2.0bar you are way outside its efficiency range. This leads to heat, which leads to high EGTs, high intake temps, ignition timing being pulled, detonation and most likely a broken turbo.

 

You need to get figures out of your head, they aren't as important as you think. You have to look at what you want a car for, Drag, fast road, dyno queen, etc and then you have a good base to ask questions from.

 

What is your actual plan as far as a Supra goes? Are you planning to get one as your first car? Before your test? What are your ambitions once you get it? If it's just to crack 1000hp then you really are wasting your time/money.

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Lol got me. Not sure if the original poster is serious or trolling. We usually get these "my 1200bhp build list" threads at half term...

Running 4 bar (60psi) through a turbo because you want 1200 bhp. That's not going to happen.

It's double the maximum most people run. I think the most Jamie ran was 2.2 bar and that was only a few runs up the strip on race fuel. The amount of fuel you would need to put into the cylinder to stop det at that level would be rediculous. You wouldn't need injectors you would need 6 jet washes. And that's going to add weight and slow you down. And I don't think a mega squirt ecu can control them...

Even 40psi is borderline rediculous.

 

Also your not going to run 2 turbos in sequential ether. Unless you have a rediculous amount of money to spend. I think it's been done one or twice by an American company but the amour you have to spend for the benefits you get i silly. I think it was a proof of concept more than anything.

 

If you want 1200 send your car to Titan or SRD. Or whiffbits. People who have all done 1200bhp cars. And save money.

 

Good luck with your 4 bar sequential 3.4l build. But your having a laugh. With the greatest respect... I don't think you know what your doing.

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Lol got me. Not sure if the original poster is serious or trolling. We usually get these "my 1200bhp build list" threads at half term...

Running 4 bar (60psi) through a turbo because you want 1200 bhp. That's not going to happen.

It's double the maximum most people run. I think the most Jamie ran was 2.2 bar and that was only a few runs up the strip on race fuel. The amount of fuel you would need to put into the cylinder to stop det at that level would be rediculous. You wouldn't need injectors you would need 6 jet washes. And that's going to add weight and slow you down. And I don't think a mega squirt ecu can control them...

Even 40psi is borderline rediculous.

 

Also your not going to run 2 turbos in sequential ether. Unless you have a rediculous amount of money to spend. I think it's been done one or twice by an American company but the amour you have to spend for the benefits you get i silly. I think it was a proof of concept more than anything.

 

If you want 1200 send your car to Titan or SRD. Or whiffbits. People who have all done 1200bhp cars. And save money.

 

Good luck with your 4 bar sequential 3.4l build. But your having a laugh. With the greatest respect... I don't think you know what your doing.

 

This was the reason for my sarcasm, I don't wanna knock an enthusiastic young man, I mean look how young C.Bailey pulled through :D. But I do worry about this chap :)

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Power will be related to volume and pressure, not just pressure. The RPM of the turbine will be unsuitable for the bearings at some point. So a never ending boost increase won't always benefit the mechanical parts of that turbo.

 

pressure is not comparative against pressure, the volume of each pressure is what really matters. Comparing a turbo's flow will be more accurate than a pressure times cylinder equation. Maybe using the same turbo for different engines would work that way.

 

This is why the exhaust housing is so important.

 

I'm sure a comparison of flow and turbo exhaust housing and compressor size equation would help to understand the difference in psi and volume.

 

Unless you are prepared to take some lengthy time doing maths to have a result which may or may not be accurate, I would just use other peoples builds and component combinations to find your target power.

 

Peoples opinions on what can reach that power will always be different to what actually can and that's not their fault just people taking for granted whats possible without evening doing comparison research. Look at builds, they are accurate to what can be achieved. I always read what can or can't be done, a build thread never lies on the final dyno result.

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All turbo's are 1000bhp don't you know? That's like the basics.

 

Word!

 

Fit 2 and have 2000hp.

 

Church!

 

2000bhp stock. That is the reason why stock twins are better than going single.

 

only if you fit one of those laggy old school T88 Turbo's ;)

 

Why stop at 3.4l? Just go whole hog and bore it out to a 4.0l then add two of these bad boys:taped:

[ATTACH]175986[/ATTACH]

 

you would be better off fitting an elevator in each bore :blink:

 

Then you could put in those electronic supercharger fans into your intake for another 500 or so bhp. The limitless potential! :cool:

 

money saving tip, run your AC through to your air-inlet.

 

 

Ask any racer, any real racer...............

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