Just want to let you guys know we going to be building GT28R and GT28RS twin turbo kits. Here are some info on the kits

Flows 35-37lb/min each (internally gated)
1/2" flanges
8ga 304L SS manifold
304L SS 3" downpipes (O2 bung on each DP)
-4an oil lines and fittings
5/8" ID oil dump lines and fittings
All nuts, bolts, gaskets, ect.

These turbos are plain bad *** and will make for a great street/strip setup. We're making some minor adjustments to our welding, so expect the highest quality welds.

There is a group buy going on right now. Here is the link

https://www.rx7club.com/showthread.php?t=373275

 

Great idea, I was planning a similar set-up myself. As an observation, you are building a kit on a t25 turbine and the biggest turbos available for that. No room for further upgrades. I would consider a set-up based on a T3 turbine housing that will give you more options for the future. I think for a mild street port the turbo chioce is right but for a bridgy you would need to reconsider.

Have you guys tried the set-up and what were the results?

Thanks
CW

 

Arent these the "Disco Potato" Turbos?....These are sold as a kit for the z32 (90-96tt 300Z). On the Z I believe they are rated at 700hp (as a pair). If so their flow charts are available on JimWolfTechnology.com or http://www.jimwolftechnology.com/cus...asp?PartID=442

 

Right, they are the disco potato turbos. If you look at the compressor map, and compare it to the GT35R map, you'll see something very similar

 

pictures?

Are you interested in selling just the manifold and dp's for people that want different turbos? If so how much would you want for just the manifold and dp?

 

John,
I am really interested. Would you care to comment on my post above, please.

Thanks
Claus

and tell Jason to get his facts straight on the other post. I guess he is offering 2 pretty desk ornaments with the kit (your choice of anodized blue or red) or are you building a set-up with external wastegates as well.

 

Any more specifications on the the turbos?

 

The GT28R and GT28RS specs can be found here

http://www.turbobygarrett.com/turbob.../downloads.jsp

Z8CW, I hear what you're saying but you have to understand that 2 GT28RS turbos are nothing to take lightly. Both of them combined will make for a hell of a setup. I can't imagine selling too many twin turbo kits that are bigger than the GT28RS. Don't get me wrong, twin GT30R turbos would just be amazing. But then you would have to consider the extra cost of the turbos, and wastegates. I would love to build a twin T3 kit, just don't know how many people would buy.

 

Yes, buying just the manifold and dp will be no problem.

 

John,

I guess what it comes down to is what one will get with the twin gt28r over the single gt35r. The RS is $ 400 more each retail, so this kit I assume will be way more expensive than what Jason indicated.

You are right comparing just the flow charts, it looks like the gt28r flows basically half of what the 35r is and will most likely make the same power. So, does it come down to spool time and response? How much quicker does your set-up spool?

Thanks
Claus

 

How would they work on a semi pp 13B REW ?

 

Which exhaust AR do they come with? There is the 28R with a .64 and the 28RS has either the .64 or .86.

What are you guys planning on doing for the turbine side?

Also, since you said you'd be willing to sell just the manifold and dp's how much would you sell them for??? Do you have any pics of it or can you give me any info like the runner length of wach one, ect???

Thanks for the info
Stephen

 

Both the GT28 and the GT28rs turbos put out less than half of the GT42 's flow , so whats the benefit of having them ?,is it less horse power for faster spool ??. One of the GT28 turbos cost $775 and the GT28rs cost $1179 !!!. One GT42 costs $1950 again , whats the plus ??. I'm not meaning to start anything but I am not seeing the benefits using those turbos , especially at that price . Wouldn't the GT30 (or GT3071) be better ?, but it costs upwards of $1300 for one unit !!

 

Not everyone has large enough porting to be able to spool a GT42, that is a really big turbo. This gives you quick response and still enable top end. Not everyone is looking for the highest horsepower turbo, some people want to go with a more streetable setup. They want to spool quick and still have top end power. It's a difference of opinion, no reason knock it when it is designed for a different person with different goals in mind.

- Steiner

 

I know fully well the advantages of a twinturbo kit , it has been discussed here since the beginning of time !! . I am not knocking anything , ok . But the kit is expensive , even if you would want to put a kit like that together on your own , it is going to cost a lot more than a single if its a GT42 or not.

 

Like I said this kit, from what I can see, is based towards someone who wants to have boost quickly and still have a decent top end. Yes there are single turbo kits out there that can do this for less money, but some people want something different. One of the great rules of marketing, differentiate your product from others. This is obviously different from your run of the mill single turbo kit. It is geared to a different type of buyer.

- Steiner

 

Fine , I can understand wanting to be different . I wanted to be different , get as much power as I could and still be streetable so I went with a semi pp setup from a half bp setup. The only difference is that its not costing as much . I was seriously thinking of going with a twin kit , I even contacted LT1 about getting the manifold separately and putting together my own kit , but those GT turbos are very expensive . For a few dollars more I'll get the GT42RS , have the lightning response , get the power and still be DIFFERENT!!.

 

That's fine if that is what you want to do. This turbo setup may just not be what you like, that's not a big deal. If I remember correctly the GT42R is the ball bearing version correct? If this is true I would be interested to see when you get certain boost levels with a semi-pp setup. I have wanted to see more on this turbo and the effectiveness of the ball bearing setup on these larger turbos. Good luck with your project.

- Steiner

 

I'm gonna go with .64 on both kits unless the cusomer request the .84 for a big port.

The price I would sell the manifold and dp would be the prce of the kit minus the price of the turbos, and hardware. PM me

As of now there are no pics. Runners will be long, just don't know how long as this point


Do you realize how big a GT42R is? There are very few people on this board that have the engine to support a GT42R. I think a better comparison would be with the GT40R, but then again no one can get those turbos. And when you're talking about cost wise, the twins will be cheaper. You haven't calculated the price of a shiny wastegate with the GT42.


Expensive compared to what? The price on these kits are about the same as some single turbo kits. When you you take into consideration these are twin ball bearing turbo kits, it's actually a very good deal. I myself have not even seen a twin turbo kit out for the FD, so I think my price is more than fair

Yes, what he said I'm targeting a totally different group of buyers for this kit. I have a T70 kit out right now that will push 650rwhp, but who wants that on an all street car? These twins have great spool, and has the top end to follow it

 

Umm, Aspec sells them.

- Steiner

 

I got an A-Spec GT40R kit with 50mm for sale in the 3rd Gen for sale section... complete kit, never used, comes with ceramic coated manifold and downpipe, and bung welded in for tuning for less that you get it from A-Spec

 

what does that have to do with twin GT28R turbos?

 

The concept of the twin is great...the big single is fine if you want to wait for idle out and then spool up. The twin allows for much more torque and power off of idle through the RPM .The larger T has more power but to make use of it is in a peak zone. The rest of the rpm is not be utilized. Thats why WOT with a 6-9000 rpm range is were most big T's or properly utilized and is often said to be best for drag. The twin more than likely eat a big T off the line in light to light on normal road tires. The big T will bog then spool hard later and then smokem down.

 

Do you guys actually have a kit up and running already? I'm assuming that's where your performance claims are coming from? Any dyno sheets?

 

I hope I don't appear to critical here but saying that this twin is an expensive set-up compared to lets say the A-spec GT35R is just not correct.

The two turbos are an additional $150 over the larger single.
You save close to $ 500 on the wastegate (tial 46mm).
There will be extra fittings and pluming for the twin, lets say $50

As for the manifold, there isn't probably that much of a difference since you don't have to fabricate the pipes for the wategate but obviousely need two down pipes.

So, really, just looking at the hardware you should save close to $300.

Of course this is all based on retail prices and me only having experience with fabricating a single set-up, never a twin.

In any case it looks like we are looking at close to $1k extra to fabricate the twin manifold???

What am I missing?

CW