Turbocharger Question
 

I have heard many different versions here locally. Could someone please tell me the advantages or disadvantages of a hybrid K24/K26 over a stock K24.

Also, the usual south florida suspects can refrain from this thread, I have heard your sides. I want to hear from other UNBIAS knowledgeable sources. Don't mean to hurt any feeling, just tired of hearing everyone (TUNER) bash each other.


Its a basic question, I want to upgrade my TT from the K16's to a..........???

Please help!

Thanks

The choice of a turbo depends completely apon the HP goals for your car, taking into account cost etc...

I think a tried and tested method is to get the k24s from the gt2. Along with chip and fuel you should be in the 550-600 range.

At the present moment, I have FVD exhaust with 100 cell cats, and computer. FVD is stating a 467HP to the wheels, I don't think its even close to that number. I guess the only true way to find out is to dyno the car.

Assuming the standard 1.20 multiplier for wheelhp to flywheelhp
467 * 1.2 = 560.

I REALLY doubt that ecu, exhaust and cats can give you 140hp over a stock turbo.

For a non x50 turbo with ecu exhaust and filter from evoms they list 505 hp (from stock 415). I believe that is flywheel. These numbers are much more reliable IMO

Kevin, compressor is the hot side right?

Also, what wheel will support 800hp?

Does the gt1 setup all use the k16 housing?

Compressor is the cold side

Kevin,

From what I have been told its a K24/K26. It is not a K16 housing. I am not looking to get 800hp............. thats crazy IMHO.

So what do you think is my car's true HP output with the ECU and exhaust to the rear wheels?

Kevin - I have the same question...Does using a K24/K26 as a bolt on turbo even make sense? Wouldnt that lag like crazy?

Which turbo's is a question like which wheels, there are many choices. I am running the Garrett Dual Ball Bearing T04 and love it. It makes massive power 586 hp 563 tq to all four wheels. If you come to the National Meet you can get a ride in all the different cars and see for yourself what you like the best.

That is what is awesome about having this National Meet is too see all the different things you can do to your tt. It will also cost you alot of money which I take no responsibility for!

My car pulls in 5th like it does in 2nd it is amazing!

hilarious

Very well said Buddy I could not agree with you more

I don’t remember if Buddy had open exhaust at the shoot out but, when it would decelerate all the way down to idled he’s turbo’s had the wildest sounding whistle. Are those what they call Garret 30’s?If it was doing that through a muffler, I’d pay just for the sound. The only bad thing I heard about them was when Cort said “I couldn’t get that red thing hooked up off the turns because every and anytime I stood on it at the exits …. All four tires lit up and pulled me off line!” Sounds like the Red Beast is ready for flares and slicks!! If I had Buddy’s money … I’d have some of those turbo’s

Kevin, I have the APR chip that has hotrod programs for both the K16s and K24s. I drove the By Design TT cab that was at the shoot out with the GIAC chip and K24’s and loved it. I was thinking I’d just do the K24’s and be happy because my programming supports that setup. If I went with your modified K16’s, would my software support them basically as K24’s?

Cary,

My compressor side is alot bigger than T04E's. :) However, there is alot more to choosing a turbo than size.

First you must determine how much air flow is needed to reach your goal at a given engine and engine rpm. How do you find this?

cfm = CID/1,728 x rpm/2 x VE

*VE equals 10 percent on a turbocharged engine

Next you need to add boost into the number.

Pressure Ratio = 14.7 + boost pressure/14.7

The cfm requirement under boost would be:

cfm boosted = cfm unboosted x pressure ratio

In the turbo world, engine airflow is measured in pounds/minute. To convert cfm to lbs/min. a good rules of thumb for 80 degrees F @ sea level is to multiply cfm by 0.07.

lb/min = cfm boosted x 0.07

Generally, on a high performance EFI engine, every 1 lb/min of airflow is worth approx. 10 hp, so to find the required lb/min for race applications, start with hp required, then divide by 10

lb/min = hp/10

Every compressor has a definite combination of airflow and boost pressure at which it is most efficient. When choosing a compressor, you want to position the point of maximum efficiency in the most useful part of the engine's operating range. As efficiency drops off, heat transfered to the air induction side of the turbo goes up. That is bad for both power and durability.

*credit Marlan Davis and Turbos

Actually, I believe Buddy is running T04B's, which is the predecessor to the T04E's. Protomotive used the T04E in my former blue car. These are much more efficient than the B variety.

If I had kept my car, the next step would have been the Garrett GT30 watercooled center section turbos. These are way more efficient than the T04's and good for lotsa, lotsa power and quicker spool up.

With Protomotive's programming, there really wasn't much lag. I would start boost at 2500rpm and would get full boost by 3500. Not bad if you ask me. It's just that there is an exponential power increase as you build revs.

Chad, what compressor side are you using? I thought your Turbos were smaller than the Garretts. N.B.-- At some point, the K16 on the hot side becomes a limiting factor in producing big hp for sustained periods.

The zero clearance hybrid Turbos are very cool indeed. The spool quickly and has a lot of usable torque and hp. They just don't put out the same power as the Garretts on the top end.

My GT2 will probably get some variation of the K24 race turbos. I think these are just fine for the car. Garretts would put the GT2 sideways in almost any gear! ;)

Kevin,

We ditched the GT25's two changes ago. :)

http://www.986host.com/albums/DUANEB/turbo_18_001.jpg

I don't have a pic of the turbo's currently on Killer Angel. The above were the set we just removed. The carbon fiber intakes are 80 mm, the inducer inlet is 90 mm. We are running the second largest impeller available.

Kevin, I think I talked to you about this one before on the phone but, what’s your opinion on this. I have an extra set of 993 GT2 EVO turbo’s from my zytek car which I think I’m going to put the GT30’s on. So, if I exchange the hot housings (after coating) from my 996 turbo with the housings on the EVO turbo’s, does that make the turbo’s exactly the same with the only difference being the exhaust bolt pattern, in which case it might be easier to just change the flanges on the cats. And second, will this make the same HP as the stock k24s? I’m looking for at least 600hp to the crank on race fuel and would love to make that much on pump fuel, however, I’m not willing to start changing lots of other parts such as injectors, intakes etc. My other car is the car I want to make the big power with so, in the mean time I trying to do the “budget” 600 hp

Cary,

Just get yourself a set of the K24 race turbos, like the ones on the By Design cab.

They are good for 600hp.

Tyson... I'm just wondering though are those the same as my 993GT2 EVO turbo's with only a different cat bolt flange.. if so, I'll just use those because I already have them.....

Cary,

Talk to Shank. I believe his first modification, with Roock, used those turbo's. I remember him being a little upset about the different bolt flange and the older turbo's.