J Chen

Yes Tony,
Caught you, I knew that you'll never gonna sit back
on this claim. But Tony, those nos are from your
highly modified engine right ? What about when used
on a standard 2.5 ? With improvement of VE on a
modified head, running 18psi is totally different from
running 18psi on a standard head.

chilibluepepper

TonyG -
The engine is a work currently in progress, but it will use the stock turbo downpipe/intake manifold/throttle body/exhaust manifold for now. I have to stop the bleeding somewhere! Exhaust will be 3" all the way back. I will be using a 2.7 head, but the jury is still out regarding valve springs and camshaft. The car will be used predominantly for hard DE use, with potential for more if things go well. Definitely not an auto-x car, or a daily driver - the permanent monkey bars inside, and no air discourage that!

TonyG

J Chen

Hey....

You're correct about the VE improvement due to the top end of the engine... as well as all the other things like the header, etc..

On a stock engine (with the typical bolt on stuff) it's pretty easy to get a 60-1HiFi to churn out 360Hp - 370Hp at those boost levels... (just like it is with other turbos out there).

The thing that I like about the 60-1 compressor is that it flows a ton at lower pressure levels.... which what you want.

Somewhere I've got a boat load of dynos with a 60-1HiFi bolted to a KKK replica 8 ball bearing setup (the original setup that Tim Richards sold me on the Red Car).... on a stock engine (with the usual bolt-on stuff).... and it made an easy 365RWHP at 18psi.

TonyG

streckfu's

Please find them. What is the going rate for a 60-1HiFi abd how is it boltedto the #6 hotside versus#8?

TonyG

chilibluepepper

You need to at least properly setup the foundation for the car now... or you will be ripping stuff apart later.

Use a 60-1HiFi compressor/wheel, dual ball bearing center section and a T04 - P trim turbine with a tang-undivided housing with a .84 a/r (which will be a tight turbine for a 3.0) - Call Innovative Turbo (they have the dual bb centers).. and believe me.. these suckers are worth every penny.... they are the ****.

And you'll need a modified drivers side motor mount. Tim at SFR or MySwiss can provide you with the modified engine mount and "O" ringed spacer (needed to have the large turbine clear the engine block).

You'll need to use a 3" down pipe because the "P" trim has a outlet that is larger than the ID of the stock downpipe.

Dump all the heat sheilds on that side of the engine (except the motor mount and starter sheilds), and use Thermotech as a blanket from the turbine side back down about 18" down the firewall. Wrap with stainless safety wire loosely. This will knock about 80% of the heat of that side of the engine down to almost nothing, and make it about 200% easier to work on the engine.... Summit Racing sells the Thermotec insulation. You'll want the large "header blanket". You just use scizzors to cut as needed. You'll have extra for the future... which you'll use for sure.

If you have stock rods, then you'll also have a stock redline. However, since you have more displacement than a 2.5 (a lot more) you can use a cam that would be largish on a 2.5... which will be about perfect for a mild 3.0. Use the "middle" John Milledge Cam with his race valve spring / retainer package.

Lastly.... your 2.7 head has oval ports. The 2.5 intake manifold has round ports. Although you could do a port match and bolt it on... It's by far not optimal as the intake charge will be slowing down as it enters the intake port... which is exactly the opposite of what you want. The top end power won't be affected... but the off-boost power will be... and thus your transition to boost will also be affected.

It's possible to cut apart the stock intake and hog the crap out of it (I did).... and on a 2.5 head it works well... but I'd save the money had use your stock intake until you have some extra cash and get an aftermaket intake (SFR or Lindsey) with has runners that are the proper dimension to begin with. You can pick up another 20-30RWHP at least with a good intake manifold.

TonyG

TonyG

streckfu's951

Call Turbo Bob at Turbo Performance www.turbo-performance.com

He's real reasonable.

TonyG

azmi951

Well sorry for the delay in posting a response but the computer cenoring system picked up the KKK and wouldnt let me onto rennlist at all.

I think that I will go with the k27-6 because of the drivability. I also just got a stock turbo with a waisted impeler wheel and housing but a good hot side from Eyal 951.

Are there any other limitations like injectors or AFM (to a MAF) that would need to be upgraded?

Thanks for all the help.

Sean

chilibluepepper

Thanks for all your insight Tony -

Although I'm not ready for the turbo just yet, I wanted to take advantage of the discussion in progress. As soon as I get closer to turbo time, I'll definitely be talking to Ola at Innovative Turbo - he put together the 26/8 I previously mentioned. In the meantime, I'll talk to Milledge about his valve springs and camshaft, and continue with work on my short block.

mrfixit951

Does anybody have a comparison dyno of a k27/6 to a k27/8 on the same vehicle? I agree with Tony on the importance of getting the max area under the curve for the street. But I am concerned with the turbine side pressure ratio. Is there a different #6 hotsides from other vehicle that might flow better?

J Chen

Than the only other option for you would be
to go my route by installing a GT25TO4S bb turbo
but it is not a buy & fit affair. Plenty of work involved.

TonyG

mrfixit951

Why do you think the exhaust gas pressure ratio is an issue?

And what power are trying to acheive?

You can pretty much compare dyno sheets from a K26/6 car to a K26/8 car to answer your question. The compressor doesn't determin spool up characteristics. The turbine side does.

TonyG

TonyG

JChen

The GT25TO4S, with a .64 a/r ratio is rated only to 400HP.

The same version of the turbo with the .84 a/r ratio (which is WAY too big for a 2.5L 4 cylinder ) is rated at only 440HP.

These are Bhp numbers (crank HP.. not wheel HP) BTW.

So the obvious choice to compete with the GT25TO4S would be the K27/6 which will produce 400 Bhp all day long with the spool up of a stock non TurboS turbo.

The part number for the GT25TO4S with the .64 a/r ratio turbine (the only one that's properly sized for a 2.5 951) is 446179-0018, and the link the web page with the specific info on that turbo is: http://www.turbofast.com.au/GTseries.html

I've got dyno sheets of a stock engined K27/6 car with the usual bolt-ons.

Do you have dyno sheets (SAE corrected.. not Actual HP) of your car equipped with the GT25TO4S?

It would be very interesting to compare results. I don't think that the GT25TO4S would justify any additional expense over that of a K27/6 setup (on a stock engined car with the typical bolt-ons).

Post em!

TonyG :-)

hosrom_951

Tony: I was TOLD that a T04E with .50 a/r could hold 500bhp........is that make any sense?

TonyG

hosrom_951

That turbo is on the small side for a modified 2.5 944 turbo. It will not be enough for a modified 951 (big valve, ported intake/exhaust/big cam, header, etc..)

Here's the compresso map:



Now here's the map plotted against the engine:



What this map shows is that a 951 engine that is equipped to run past 6500 and above rpms will run this map out. Likewise, a 951 engine that runs lots of boost will also run out of compressor. The compressor isn't properly sized. It is a tad too small.

It will make good midrange TQ, the the HP will suffer. (assuming that the car is equipped with the proper sized turbine..... however no turbine will make up for a compressor that is too small).

Bottom line... this compressor is really more suited to a 450HP car than a 500HP car (on a 2.5 951 engine).

On a 2.8 or 3.0, this compressor would be way too small.


TonyG

hosrom_951

Hmmmmmm, so what turbo would be suitable for both stock engine (for now) running 18psi, then later on adding the usual MAP/MAF, Injectors, WG. exhauts.........basically in the future (even after rebuilding the car) im not going for something like 400+whp, more like ~350 which is more than enough for street driving (for me anyway).

I was aiming for the KKK27/8, but got an offer on this turbo:

K26 with T04E compressor housing with .50 a/r ratio.........

Could a K27/6 make my desiered goals at 18psi?