nman413

Some interesting reading...

http://www.hotrod.com/techarticles/e...bo/index1.html
http://not2fast.wryday.com/turbo/maps/
http://www.turbomustangs.com/turbofaq.htm

viperbob

And what did you learn from these Jauder?

K24madness

I would love to do a stage2 compressor at some point. I have had to source out another rebuilder since Kevin is unwilling to work on my k24's. He will only work on my K16's. I found a very knowable turbo guy on the east coast that can do the work. We are looking at a few different options based on my desired flow and pressure ratio. I am very comfortable working with this person since he will provide compressor MAPs for me to help determine the best compressor wheel. He will also take into account the lower shaft speed of the K24 turbine. My choices are not limited to a "bolt on" wheel since he has the equiptment to resize things as needed. I will post some before and after results alone with how I plan to control fuel and timing to optimize each setup.

nman413

Bob, lots to learn

Got to admit, it's kinda fun looking at this since it's a nice change from staring at visio diagrams and contract papers.

Jean

K24madness

Just curious, why don't you use your K16s to have them modified by Kevin instead of your K24s? Do you have a different objective in mind?

Jean

hatchy

K24Madness,

What other options are you considering outside of K series snails? The Garrett GT28R looks fairly interesting. I have K24s too, and they work very well (never driven a K16/24 so I dont know how they compare, but my car feels MUCH faster then a stock 993TT).

Jean

I think moving to Garrett housings is a totally different ball game, you will need to do exhaust modifications or find a special adapter flange at least. For much less money than the GT series you can get a modified stage 3 T04E that would flow enough to take you to 800hp with good low end response. They have the same compressor and don't need as much cooling as the GT30.

I believe that Kevin's K16s stage 3-5 turbos will perform at least as as well as all these, but as I always say, I don't know much about this and I am just repeating what I heard from talking to different knowledgeable people.

hatchy

The TO4Es are old-school turbos, I am sure they'll work fine, but they are not the same as the GTs. Here is a comparo between the GT30 and a T3/T4.

http://not2fast.wryday.com/turbo/map...460-110psi.pdf

KRA993tt

Bob,

I totally agree. Not trying to go off on a tangent but with my set up K24's/Modded ECU the engine is just flat on anything less than 98 octane. On the dyno we saw spikes just over 18psi. before stabalizing around 15psi. I don't have a manual boost control. I doubt I have enough restraint to be trusted with one .

viperbob

Keith - If you think you can not control yourself, then it is a mod that you most certainly should do..

K24madness

Since lag is not an issue with my car I see no reason to introduce any additional back pressuse from the smaller K16 hot side.

KRA993tt

Bob,

Well, I am putting together a to do list for this winter .

Jean

I missed this post.
Hatchy, thanks for the links, but I don't think they prove the point. I think some clarifications need to be made.

We don't know anything about the specifics of the runs or cars under which conditions these were tested. The torque curve shows that they were at two different boost pressures and calibrations, also there is a big flat spot in the lower curve that is not present in the higher curve, which means that they might have made hardware changes between the 2 runs or serious calibration changes.
It also depends on what trim you are using, if you use a GT30 with a 60 trim compressor it will be laggier than a T04 with .54 . They both use the same E compressor. Also I have heard of people using GT30s and getting amazing boost response however no power gains beyond 1.2Bar.
There is no doubt that the GT30 are more modern and they use lighter turbine wheels (titanium?), which is what Kevin uses as well I believe, but I don't think the difference in price is justified.
BTW Protomotive's tuner shootout car was using T04s and made big power gains on the GT30 at the same boost pressures.

Also, GT30 will need better cooling than others, which can be a challenge in our cars.
I am sure Kevin, Stephen and others can provide better data and opinions and might correct me if I am wrong.

The information provided above is not from personal experience but from people who have extensively tested both turbos.
Jean

hatchy

I don't know the specifics, I understood to be on the same car but not sure about the boost levels.

If Protomotive was able to make more power on a T04 over a similar trimmed GT30R (I assume we are talking about ball bearing GTs vs old school T04s), I'd be very surprised.

As far as the GT30s running out of steam at 1.2bar, that may be true, but the GT30R seems to stay in its sweet spot well into the 25psi range.



I have a PTE built t3/t4 , and for the money, it is definitely the value leader. But for my next project on my 2.5L motor, I am going with a GT28R or GT30R.

Jean

Hatchy,

I don't doubt at all that the Gt BB turbos are great, and maybe the best you can get for high hp applications. My point was only as you mentioned, that they provide a great bang for the buck.

We've gone way OT here . Thanks for the info.
Jean