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Discussion Starter · #1 ·
Does anyone here have or have ridden in a Supra with the Blitz Twin Turbo Kit setup? Wondering how fast the turbos spool and any other info.
 

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Discussion Starter · #3 ·
That thread was real cool, but I was more looking for if anyone know about the performance for the Blitz twin turbo kit. I mean, the HKS 2835, from what I hear is really slow spooling and not very good, but I saw this kit and read how it was designed with germans and wondered if it was good or not. Also, if it was up to you between getting 600hp twins and getting 600hp singles, which has the least lag?
 

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Alpine Hardtopper
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I understand what you're saying about the HKS kit. I've considered that one as well, and just figured they were larger than my needs. However, I have heard of people doing the GT2825 turbos (I believe that's the right one) on the rest of the HKS kit. Talked about virtually no lag at all, but was limited to ~650hp. It's been a while since I read about that setup, so my numbers could be off.

People usually have two meanings to the word "lag." So for the sake of clearing things up, lag is the time between when the throttle is opened and when the turbo reaches the steady-state RPM for the engine RPM currently at. For example, lets say you have a small turbo that is set to put out 15 psi of boost at 4500 RPM. You're driving down the road with the tach at 4500 RPM then step on the throttle. Lag = how much time it takes the turbo to reach 15 psi.

The other name that commonly gets lumped in to "lag" is called "boost threshold." This deals with what boost pressure can be achieved at a given RPM under steady-state conditions. Even with a small single, you're not going to make any boost at 1500 RPM no matter how long you wait there. The simplest way for most people to test this is to do a 3rd or 4th gear pull down the freeway, or run on a chassis dyno. It should be defined by a boost vs RPM curve, but some people define it as a single RPM point - the RPM where the turbo first starts making boost. Other people define that point where it reaches their set point for boost control (kind of bad definition because it will vary depending on what your boost is set at).

Lag has more to do with the rotational mass of the turbo, and friction of the bearings. Boost threshold is really more the size of the turbo. Ball bearings usually improve lag quite a bit, while they do little to effect boost threshold.

With that background, running twins usually doesn't improve boost threshold. Given a single, or a set of twins (assuming parallel) that are capable of similar power output, both setups will likely have a very similar boost threshold. However, where twins absolutely outperform singles is in lag. The rotational inertia increases by a factor of radius^2. There ends up being a significant improvement in reducing moment of inertia by running two small turbos over one larger one capable of the same flow.

But all turbos aren't created equal either. Two small journal bearing turbos (read: stock twins) are going to have more lag than a similarly sized bb single turbo. But two bb twins should have a distinct advantage over any single when it comes to lag.

All that being said, I don't know if the Blitz kit uses BB turbos or not. I see that they're using KKK26 housings (same as on the older 5-cylinder turbo models). I know mine weren't bb turbos on my 5kcstq, but the ones in the Blitz kit may be. One thing for sure....they are tough turbos. My first Audi didn't come with a BOV or bypass valve, and the original turbo was still running strong at 175k miles!
 

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Look into the SaRD Racing kits as well.. very well built, a little more exclusive and they use the same 3K turbos as a base.
 

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Discussion Starter · #6 ·
Cord, that hole write up was awesome! Thanks man. See everyone here loves to go single and for me, after I saw the blitz twin kit, I was like wow....they do call it a Supra Twin Turbo, right?

And from what suprastore says, it can produce around 800hp. So if they are bb turbos and twins greatly reduce lag, then the only reason I can see for me to ever really go single is.....the price of the kit? Screw that. I want this kit really bad.

I just wish there was some more documented experience with this setup in someones supra. Guess I'll have to be the first to write about it.


Epik, where would I find those racing kits?
 

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A Blitz TT equipped Supra held the outright laptime record for the Nurberg Ring in the 90's...nuff said. :)
 

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Alpine Hardtopper
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No problem!

In my case, I love to road race my car more than drag race (okay...I like drag racing too, but I'm not building the car for that purpose). In all practicality, smooth powerband, quick spool, and 550-650 rwhp is about all I can imagine being useful given the tire size I can fit. In my situation, getting a DBB single that supports 650 hp will probably offer better performance for me that the Blitz kit (capable of 800 hp) being run at 650 hp.

I've actually thought a lot about buying the HKS manifold/headers, and just running smaller twins on them (peak around 650 hp). It's just so darn expensive to piece together a twin setup! But a twin setup makes even more sense when you have a split (V, or flat) engine.
 

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ArmySupraDude said:
And from what suprastore says, it can produce around 800hp.
Not to sway you one way or the other, but if you look at suprastore they almost always quote horsepower levels, increases, etc. based upon what you would get at the crank, not at the wheels. So in all reality you are probably looking at more around 680 rwhp...which is still plenty for me!
 

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Alpine Hardtopper
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That seems a lot more reasonable out of the K26 housing. I couldn't imagine anyone running 400 rwhp with a single K26....but 340 rwhp seems possible with one of them. It would be nice if they offered more information on the turbos (even a compressor map would be nice!). Not to mention offering some extra parts to help plumb/exhaust it all together.
 

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Discussion Starter · #11 ·
Well honestly, I was looking for a modest high 400's, but after seeing the Blitz kit and looking at my car. It was meant to do more than that.

Plus, me personally, I like to be different from everyone else and if this kit was good enough to set records at nurnberg ring in a country full of supercars and it isn't a single turbo, then thats for me. Plus the pics of it are beautiful. Picture perfect.
 
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