Great work on the kit Tim, the power those turbo's make per boost is just crazy. If only Kevin can get either his fuel system fixed if there is anything wrong with it, or an adequate fuel sys for his needs.

 

We like dicking around and fabricating stuff....haha. I'll call you later.

 

This is amazing coming from a turbo kit "designer"....

Well, here it is. There should be NO correction used, period. The difference between STD correction and SAE correction is small. SAE corrects TO 25 deg C (77 degF) and 990 millibars, whereas STD correction corrects to 'standard conditions', which in inorganic chemistry is 1 atm and 15 degC (59degF), hence it's somewhat similar.

Just because you can't understand why the correction is inappropriate, doesn't mean that it IS appropriate. All you have to do to understand it is think about it for a second, and if you (or any one else), doesn't believe me, they can look it up on their own.

1) STD/SAE corrections are corrections used for NA cars, not for turbo cars. Why? Here is the answer: An NA car at sea level (L.A./San Diego) has 14.7psi of air to work with and use for combustion. Simple? Yes. The same car in Parker, CO at 5868' above sea level has only 11.8 psi to work with (available for combustion). Now you put that car on teh dyno, it will make that much less power, about 20% less. Hence, teh SAE correction to predict what that car would make at NEAR sea level.

Now, you take a turbo car with 14.7 psi of boost at sea level, it has a total of 29.4 psi of absolute air pressure available for combustion. You take THIS car to Parker, Colorado, with the wastegate/boost controller setting unchanged, it will make 11.8psi ambient + 14.7 psi boost = 25.5psi of available air. Remember, the engine sees 25.5psi, it doesn't care what the boost really is OVER the ambient. Running your car at 14.7 boost in CO is the same as running the car at (25.5-14.7)=10.8psi of boost at sea level, and they will both make the same power at 14.7psi (CO) and 10.8psi (CA). BUT BUT BUT the beauty of the turbos is that they can be adjusted by the boost controller to develop more pressure so that you compensate for the thinner ambient air. So, if you are making 10.8psi here in L.A. and you want to go to colorado and compensate for the thinner air, you would have to run more boost over teh ambient, 14.7 to be precise.....that's why it's sometimes better to just look at a MAP-based pressure gauge, that just tells you total pressure. So is it to say you don't lose anything if you go into higher elevation with a turbo car? NO, you lose a little efficiency because you aren ow operating in a higher PR bracket (pressure ratio). To develop the same 25.5 absolute psi in the engine in CA you are running at 25.5/14.7=1.73 (PR), while in Parker, CO that number would have been 25.5/11.8=2.16 (PR). Just look at a turbo compressor flow diagram and hte label on the Y-axis...it says 'PR'. With higher PR, you see lower efficiency... Most of hte time for change like this, the loss in efficiency will be about 4-6%, and NOT 20-30%.

BTW.. If that car tuned at 14psi in CO came down to L.A. with a 14.7 psi boost setting, it would most definitely suffer a tuning-related failure, especially with a SplitSecond box.

And here is a word about questioning dynos, Tim, yes we should demand that all turbo car dynos be posted uncorrected. That's fine, but it's also not a problem if the car being dynoed at sea level with the correction applied, sinice it will only be 1-4% max. But when the correction factor is 20-30%, than that's singnificant...and that's not BS.

I know you mean no harm here, and you weren't being surreptitious, you are just plain wrong about the correction...that's all. So, let's move on.

 

Obviously, i totally agree... We just need to keep people honest that's all. It's a good thing for the community.

 

That pretty much proves my point and my calculations.... If your car was NA and dynoed in Parker, CO at 640hp SAE corrected, in theory, it would still dyno at 640hp SAE corrected ANYWHERE, including sea level. But that's just not he case in turbo cars.

I do want top say that lookign at the dyno, I do mnore or less like the curve, since i gnerally prefer top end over midrange. But, I think those turbos would truly shine on a stroker car, where high displacement would spool them up faster.

 

When you figure out how to make every other shop post uncorrected dyno charts, then we will too. We talked once on the phone about some short and long term fuel trim or something like that so...I dont know what BS you are reffering to. And since I am a man of honor I wont bring up the fact that your past experience with FI and motors would make most people cring in disbelief.

 

Anyway, those things are no secret, and that I was screwed time after time by the people who did the work is no blemish on my character and knowledge.

We spoke about your turbo kit and why I should buy it, a long time ago when i was still shopping for one...

Anyway, let's drop it. Those are not bad turbos, but they will truly shine on a larger displacement engine, where the mid-range won't be sacrificed much.

 

Shoot, why stop at 1000cc? In my humble opinion... go for 1200cc at least unless your planning on running race fuel and higher compression.

Can you give us more info on the TF fuel system?

 

...edit...

 

I think 519WHP is highly inaccurate and please let me explain why.My stock motor car with stock everything except for the turbos systemand 3" exhaust made 440WHP @ 8.5 psi, 456WHP @ 9.5 psi and 476WHP at 10.4psi on the Dynojet at 750ft elevation.With a very conservative tune I might add because 20+K miles later my car is still running strong. I made these numbers on a couple different occasions in front of some of these guys on the boards.From 8.5 to 9.5 psi my car made an additional 16WHP. From 9.5 toi 10.4 it made an addtional 20 WHP.Notice the horsepower is now increasing per psi of boost because the turbos are getting into their peak efficiency zone.With that being said, my car with an additonal 3.6 psi of boost would theoretically make 548WHP at 14 psi of boost.


So now we have Kevins car.It has a built motor which doesnt mean much except that it is stronger and possibly has less rotational mass. Compression ratio of 10.3 to 1 from the stock motor to his 9.6 to 1 is very minor. But he has a ligthweight flywheel and clutch. He has an upper plenum, He has cams,he has a Utec which gives you a much better ability to tune with then the SS box since you can actually advance timing instead of just being able to retard timing with the SS box.So with this being said,there is no way in hell his car would only make 40 more horsepower then my car with all the extra components which have been proven to make power on N/A and FI car and running almost 4 psi more boost.It is just impossible.

 

Not at all. However, I am not going to get into a bashing war and have this thread closed. That gets riduclous. I said what I had to say in the post right above this one.Take it for whats its worth and in the meantime we will keep working to prove that our turbo system will have the ability to make more power then the rest

 

you have been here a month and you are trying to stir **** up? get a clue!

 

I'm not trying yo stir the pot but Tim isn't BSing about what his car makes. I attended the SFR dyno Tim held and watched put that down. Furthermore the shop we did the dyno day is known as the Heartbreaker. I watched no less then 5 cars aside from mine put down some very subpar numbers. I even have a reference car. There was a specific car that came to the dyno that day. It had just finished running on another dyno about 3 miles away at another shop. Both dynos used were Dynojets. At one shop this car made 275 WHP. At the dyno SFR held their dyno day on it made 248. My car which has consistently put down 370 WHP and even as much as 390 WHP put down 358 WHP.

 

First off, i don't agree or disagree with the numbers. I much rather them be accurate considering the route i'm going. But, i say go to the track and lay down a trap speed. 512whp and 640whp have way different trap speeds and we should be able to determine which you're closer to.

 

Tim, I think your set up is the best!!! (the only turbo i have ever had tho!)
Your knowledge about the set up and install is top notch, you have never put me on the back burner, always take and return phone calls, if something about the kit isn't right YOU HAVE MADE IT RIGHT!!
The hp/tq # realy......don't mean Shir! to me, it's a tuning tool, shows gains or losses. I think I can safely say in Colorado, this kit in the Z has the most FI potential available at this time by far!!
Thanks Tim & SFR
Time will tell with your kits!!
Kevin

 

everyone keeps mentioning the big compressors, but I have afeeling that the use a good size turbines is what is helping this car pull up to 7000 rpms. With large enough turbines/housings, it will lower the exhaust backpressure to the engine.......with less backpressure, it is likely that the gauge will show a bit less "psi" on the gauge for a given cfm compared to a turbos with smaller turbines..like the greddy. of course, this is also probably why it seems these larger turbos are making less power in the lower rpms.....


regardless, nice work Tim......I am looking forward to testing out my new intercoolers!

 

^ I said that too. Even in the EVO/STi community, medium sized turbos are recognized for their mid-range power, but larger turbos are known to provide power up top. Thats likely the reason why the car is making power past 6000rpm.

 

This concept is not new. It applies to just about any engine. The problem is that most Z/G owners aren't hardcore enough to sacrafice a little to gain a little. Take the rpm issue as an example. The VQ has an awesome r/s ratio, short stroke, cam over bucket valvetrain design, VCT, awesome flowing heads, and 4 bolt mains with a full main girdle. The motor geometry-wise is great for revving. This 6700rpm redline is just sad and there's no reason why people with built motors shouldn't have a powerband that climbs to 8500rpm. Good thing i only have your motor. It's going in my 240sx shell and will be a dedicated 2500lb weekend street/strip car.

These are straight t3/60-1's that will be going in my car. $1600 worth of manifold materials from spdexhaust.com are on the way for my goal of a high rpm, highly efficient setup.

 

Kevin, i must have a ride.....congrats on the #'s

 

Ideally the optimal backpressure to boost pressure ratio is 1 to 1. Meaning you want to see 1 psi of back pressure beween the cylinder head and turbine for every 1 psi of boost pressure in the intake manifold.Log manifolds are very restictive so the pressure ratio is usually about 3 to 1 which is far less then ideal.A tubular manifold with long runners is the way to go to get alot closer to optimal pressure ratio.I would love to make some headers that had about 24" of runner length but there is not enough room in the engine bay so we had to settle on about 12-16" of runner length These SFR headers have almost the optimal runner length for a four cylinder Porsche motor.



And these SFR headers are perfect for an inline 6 BMW M3 motor.



These SFR headers are right on the money for a V-8 Ferrari.



And ofcourse the the infamous 2JZ.