500hp turbos- part 2

[S2central.net]

glad i see this thread starts over again.

Yes, but if it turns into another handbag session it will get closed again - with consequences for anyone posting with bad attitude.

[vti2]

The problem that I see are guys like me that want to have power between 550hp and 600hp, you have to go higher has a GT30 and lag will increase dramaticly.

[diesel des]

Thinking about this more maybe we need to make 2 lists. One list is for completely stock engine internals but assume a bigger intercooler, suitable exhaust manifold and sysyem , suitable injectors. This list will generally have bigger turbos to get to 500bhp.

The second list will have modified engines so lower compression, maybe some head work, rods, and maybe some cams like 7a or rs2. On that second list you would have turbos like gt3076r and gtx3071r etc.

Call one modified list and the other stock list. How do people feel about that? Also if a turbo can get to say 475 genuine bhp then I feel at within 5 % of target it's close enough to go on a list. Just with the extra details that it's power is slightly less or indeed more than the magic 500bhp requirements. Thoughts?

[diesel des]

Dmitri thanks for your very useful input. Stock compression ratio looks to be the problem on normal fuel then. Therefore oversized turbos are required to make 500bhp.

[prj]

There is one thing you forget, and that is octane based dynamic compression limitation.
At some point you hit a brick wall, so it does not matter how much the turbo flows.

While the GTX3071R, GT3076R and so on are all capable flowing the required amount of air, it is the ignition angle efficiency that dictates how much power you can extract from said mixture and how much you waste as heat. At 450hp on 98 RON with a standard CR 2.2T you are already wasting nearly 100hp compared to running MBT.

There are a couple solutions - one is lowering the compression ratio.
The other one is moving the powerband higher into the revrange, as the dynamic compression basically equals torque, and by moving the power higher into the rev range you are able to make more hp with the same torque.

I would say for any of these turbos to make reliable 500hp, you at least need 7A cams and a stacked headgasket would not go amiss.

The GT35R is a big turbo with big lag, it's capable closer to 570-600 on pump fuel, similar to a HX40.
GTX3071R/GT3076R are very similar. HX35S also flows about the same amount of air as the 3076R. The Bullseye S256 will also flow enough air for 500hp and has extended tip technology - spoolup is also around 4k like the others.
EFR I can't comment.

[PRY4SNO]

I went with the 7163.

Can't wait to report back how it responds with a 2.5L stroker.

[popdemonic]

glad i see this thread starts over again.

[Quattronaut]

Some efr 7163 info

http://www.full-race.com/store/turbos/borgwarner-efr/borgwarner-efr-7163-turbo.html

It's a 60lb/min turbo so 500bhp shouldn't be breaking a sweat.

Ok-I didn´t know it came later than the other EFRs, and it flows that good. Then, "easily" seems the correct term

[diesel des]

Some efr 7163 info

http://www.full-race.com/store/turbos/borgwarner-efr/borgwarner-efr-7163-turbo.html

It's a 60lb/min turbo so 500bhp shouldn't be breaking a sweat.

[Quattronaut]

I know that some dynos lie, but I have seen turbos that flow little over 50lb/min do 500bhp. 57 lb/min sounds very over the top to me. Eg a gt3076r on a 0.82 housing can be pushed to a genuine enough 500bhp on a 2.2 20vt with all the right bits. That compressor flows 52lb/min. And I'm talking no drugs here. So just good petrol 97 or 98 Ron.

On my lists, I have it with even 54lb/min; but as told I am calculating really conservative, with bad IC and no motorworks. Discussable; most people say, it´s reliable limit is around 480. Other votes?

The efr 7163 should also easily do over 500bhp.

This one I do not have in my list of technical datas, therefore it wasn´t mentioned by me. But since the the 7064 is very similar size, it should (although not "easily", IMHO ) Added:


Garrett:
GTX3071 (maxed out); GTX3076R; GT3582R and higher

BW:
EFR 7064 (maxed out); EFR7163; EFR7670 and higher

KKK:
K26 3371 O...8.12 (b:12,5mm) (=>K26/27 with "8" th); K27.2 3371 O...9.11 or 11.11 and higher

[diesel des]

I know that some dynos lie, but I have seen turbos that flow little over 50lb/min do 500bhp. 57 lb/min sounds very over the top to me. Eg a gt3076r on a 0.82 housing can be pushed to a genuine enough 500bhp on a 2.2 20vt with all the right bits. That compressor flows 52lb/min. And I'm talking no drugs here. So just good petrol 97 or 98 Ron.

The efr 7163 should also easily do over 500bhp.

[Quattronaut]

Hi @ all,
since the first thread had to be closed due to bad accents I raise that topic again. No battle for best dyno, no ecological interest for manufacturers or tuners. Keep this as an info-thread with turbochargers, that are stand-alone capable of 500 hp crank power. No E85, no WMI, nothing else.

For that power and torque lowering the CR via another headgasket or machining head or pistons is necessary; that lowers motor efficiency, but more boost is poaasible. Stock cams could be difficult to use, upgrade ones (7A, RS2 or aftermarket) will simplify it.

So as kind of an introduction:
For a certain power output, your need a certain amount of fuel burned. Burning a certain amount of fuel needs a certain amount of air. Turbochargers can flow a certain amount of air, limitted through the rpm limit given by size and material strength. That´s the secret

For reaching secure 500hp with our 20VT, you need around 1550kg air/ hr, what is ~57lbs per minute (factor is 27.126). Since all turbos use similar materials, technology and physical laws, you can conclude, that similar sizes mean similar power limits. That is compressor wheel from 70-78mm to 50-58mm; turbine wheel 65-70mm to 55-62mm.

Little over 500hp is a kind of reasonable limit in our motors using hydraulic valvetrain; bigger turbos boost later, so usable powerband gets to small for making sense in daily driven cars. Stepping over that line makes only sense with strongly modified heads with mechanical valvetrain, IMHO.

Following turbos I know the air flowing capacitiy and therefore am quite sure they will work:

Garrett:
GTX3071 (maxed out); GTX3076R; GT3582R and higher

BW:
EFR 7064 (maxed out); EFR7670 and higher

KKK:
K26 3371 O...8.12 (b:12,5mm)(=>K26/27 with "8" th); K27.2 3371 O...9.11 or 11.11 and higher

The GTX3071 and the EFR7064 maybe at limit; here the biggest turbine housing should be used. Smaller turbine housings give better spool, but choke earlier. For 500 hp a „8“ hotside is absolutely the minimum IMHO. Newer motors such as the TFSIs, are more efficient, so a "500hp-on-our-old-motor"-turbo can produce a bit more power on a newer motor. Same effect is reached by well-made headworks, good cams, exhaust, good intercooler etc. All that can help those turbos that are running at limit to really reach it.

My statements are estimated very conservative; I hate showing off with high numbers, and I wanna use material in secure and reliable manner. In addition, german DIN power is measured a little different from e.g. british, what may result in smaller numbers. So yes, maybe, that someone reaches higher numbers than I estimate, by really maxing things out

Since I do not have measurings or technical data of other turbos, now it´s on your turn list will be copied/ pasted to later posts from time to time.

Feel free to comment, add to the list or ask. Hope, that everyone keeps right accents in here If my writing sounds a bit strange for some of you, I´m sorry- my english is not perfect corrections are