ProtoCab

Who here are running K16/24 GT1 turbo's? Any flavor, not only ZC's.

How do they compare to the stock K16's in terms of spool up? Did they introduce any lag in response at all with the slightly bigger compressors, or was low down torque and response maintained, with the added benefit of more top end power?

I've just found a great deal on a set and just want some real life feedback from you guys

Acropora

Maybe just buy them and try 'em out. If you go to sell you'll likely get close to what you paid for them.

ca993twin

Ruf uses them in their Turbo R. Andial uses them in their 3.8 twin plug. Fantastic.

ScottMellor

I have GT1s in the Andial car. I'm still getting used to the difference between these and the K24s on Frank. The car is so damn quiet and smooth it is sneaky fast.

Jean

Merv

You might want to take a look at this post https://rennlist.com/forums/showpost...7&postcount=18 and the whole thread in general, it provides a nice informaiton abuot the different turbos. Some are not really comparable as they were done on different dynos etc.. but a good guideline I think.

The 16/24 will suit your street response needs as Todd mentioned, a bit short on the top end for your max HP expectations, but that is not what you are after anyways. I have driven one with those turbos, they are very nice.

911/Q45

I noticed no loss in low end, just more up top. Upping displacement to 3.8 could have covered some loss.

Jean

Despite all that I have read over the years here, I am not convinced that the RUF R Turbo and Andial use the same turbos, the K24 compressors cannot take you beyond those 500 odd HP on a 3.6 and a bit more on a 3.8. If RUF used those turbos for 490HP, while they can get you to 600HP from them then the turbos are too large for the application.

IMO, Andial uses K24 modifed compressors or K26 compressors on their hybrids, something along the lines of what Kevin used for TB's turbos that were taken to RS Tuning.

This is obviously not any criticism, just trying to find out what the correct information is.

Stock K24 compressors (K24/70) cannot go there, so something else seems to be fitted on the Andial cars.

With that being said the "GT1" turbos will be great for street usage with little lag as the graph showed.

ProtoCab

Thanks guys.

I'm really just dabbling into TT territory here as my car has always been single turbo'd. I like the idea of having GOBS of tyre shredding torque down low with a nice pair of small K16's, but have been told they will max out anywhere between 450-500HP depending on boost levels and nature of the exhaust system. I plan to run a free flowing exhaust, so I'm tipping they'd probably flow close to 450-480HP.

The K16/24's will flow anywhere between 500-550HP, but being a daily street car, I hardly get the opportunity to explore the top end of that scale

I'm tempted to just throw on the K16's and play around with them until I'm bored and then have them hybrid-ized if I feel I want more top end.

LA964RS

16/24s work great if you have a matching ECU. Been in a car w/o and you can tell the difference.

pstoppani

I have them from Ultimate Motorwerks. Love them

I can't give you a straight comparison because I also had the ECU upgraded, switched to 100 cell cats, free flow muffler, tune up, lightweight flywheel and new clutch at the same time the turbos were installed.

I can tell you that the car pulls hard all the way to redline, the power comes on quick and smooth, and the throttle is extremely responsive.

Did I already say I love this setup? Yes, I did

Droops83

I'd say that the hybrid turbos will lag a bit more, but not too much. My experience is based on driving an Andial 3.8 vs stock, and the stock turbos on a stock engine definitely build boost a bit sooner (maybe 500 rpm) and in a slightly more linear fashion. The Andial takes a bit longer but not that much, and the rush when they fully kick in is incredible! Remember though the Andial car is 3.8 liters, twin plugged and has upgraded camshafts and headwork as well as everything being tuned to match. Still a very docile and drivable car, however. If you add these turbos onto and otherwise stock engine and do a bit of tuning I'm sure you'd still get decent response and greater top end potential.

---Chris A.

TB993tt

With all the Andial 3.8s on here now it would be refreshing to see an AX22 60-130 from which one could determine exactly where and how much power is actually being produced and may throw a little light on what blowers are actually being used......

Any takers.......

Jean

Merv,

On a 3.6ltr 993TT

- The stock K16s will be gone by 450-460HP.
- The stock K24 will be gone by 500-520HP
- The hybrid K16/24, if using the stock K24 compressors will be gone before the stock K24s due to increased turbine backpressure, my guess at around 500BHP.

Sure you can crank up boost and get a bit more out of the above, but you will be hitting very low turbo efficiency ground and heat soaking quickly.

On your 3.3 Ltr engine, reduce the above numbers by close to 8-9% at the same boost levels.

As I mentioned earlier, IMO at the low end, and starting, say at 2k+ RPM or so, the car will have great response and early boost onset, but will not sustain over 500BHP.

Andial taking their 3.8Ltr cars to 600BHP+ on race fuel can certainly not be using the same turbos as fitted on the R turbo or other hybrid K16/24 sub-500BHP cars? Just check out the fantastic torque curve on the RUF R Turbo to clearly see that a similar turbo cannot have much breath left up top.

ProtoCab

Hi Jean. I understand what you mean, but since my car is purely street and only sees very occassional full boost bursts, I can push the K16's to 1.1-1.2bar for very quick short bursts

I know it would be quite a different story on a track with sustained peak boost levels, but for street, occassional bursts to 1.1-1.2bar should be OK, especially considering I'm having a massive custom intercooler built and will be installing an aftermarket DP style extended tail which leaves the engine bay wide open, improving intercooling efficiency quite dramatically. Half the intercooler will sit on top and in front of the engine cooling fan, so a tonne of air will be drawn through the IC's core, improving intercooler efficiency quite dramatically

There's no way I'd run those kind of boost levels for prolonged periods with a K16

All post turbo plumbing will be 3.5" - 4.0" diameter and I'm considering dumping straight out to atmo, via some very short exhaust silencers

From the lights, it'll be

Here's my new number plates

ScottMellor

Jean,
What you say makes sense. On the Andial build sheet it just says GT1 Turbos. Who knows what the heck is actually in there.

Toby,
Didn't Jimmy the Felon do a run for 30-160 er I mean a 60-130 on behalf of the Andial crowd?