And how does the car sound at idle? how about on a cold start? Are the pistons louder than stock. Cold vs. warm?

 

Very impressive numbers! Can't wait to see some videos beating down Supras

Kyle, would increasing the displacement of the VQ noticeably increase torque down low even with FI? Can your company stroke or bore the VQ? Thanks in advance.

 

GQ, i haven't driven the car yet so i don't know, you should ask kyle or mark, but everyone that has driven the car has said that its almost as smooth as stock.

 

He's still recovering from the shock actually, when i ever i speak to him i cant make out any real words...:-)

 

Seriously?! That is terrific if Kyle can confirm it.

Paging Kyle.....beep...beep...beep

 

Kudus car and most of the motors we have built have used our piston design which was made to have no piston noise like some of the other brands. It starts and idles just like stock and has none of the typical piston noise from the forged pistons.

I don't know about how the Arias are going to do though. We used Arias in a few 300zx motors we built and they were pretty noisey. That's why we do not use them in our motors.

Kyle
SGP Racing

 

The Aris pistons use either 2618 non-silicon aluminum, or 4032 High Silicon aluminum. The ones for the 350Z are the 4032 High Silcon Aluminum, which significantly reduces heat expansion and should make for a much quiter forged operation.

If you use the 2618 non-silicon aluminum, they will likely be noiser.

Do you know what type of aluminum they use in your setup? It also depends heavily on how the engine is installed, and insuring proper clearances and balancing.


Here is some info I googled regarding hi vs low silicon content.
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Early in the peace it was common for US forged-piston materials to contain only 7 per cent silicon in their make-up. This led to high temperature expansion rates, making engines sound 'rattly' when started cold. The Germans came to the rescue here with new materials for forged pistons which did away with the undesirable expansion rates, by containing a much more acceptable 14 per cent silicon content. As some top-level German cars have forged pistons standard (BMW V8, V12 ect) it was a requirement that these engines remained smooth and quiet, even when cold - hence the development of better materials. Now, a lot of the aftermarket forged-piston manufactures have caught on and are offering the 'quieter' high silicon content alloy.

 

Hey Kyle,

If I remember correclty didn't you also replace the stock oil pump on Kudus's car? I was curious as to why you have done this, did you feel it was necessary? Also, I was curious if you have done anything to the ignition to upgrade it? Thanks.

 

Oh, one more thing, the JE/SRP Pistons that SGP offers (I think they are JE/SGP pistons?) are made of the exact same material as the Arias...either 2618 or 4032 alumuminum. not sure which onces SGP elected for their application.

So if SGP's are quite...the Arias will be just as quite. Don't want my group buy people to be worried about that.

 

They are not JE pistons. All the turbo pistons we have made are made of 2618. 2618 is a better material for boosted cars due to its high temperature and high cylinder pressure from FI. The noise has more to do with the design of the piston and the installation of the piston then what it is made from.

I highly recommend finding a shop that has a torque plate for the boring of the cylinders to ensure a round bore. Especially since the VQ35 has an open deck.

Kyle
SGP Racing

 

Well the car is going to Doha, Qatar when we are done so we did everything to make sure the customer did not have to worry once he got the car. It is hard to find parts where he is located

No ignition upgrades were done.

Kyle
SGP racing

 

From everyone I have been told by every piston company, they don't recommend 2618 zero silicon aluminum for cars you plan on driving on the street (these companies sell both varieties). Becuase of the greater cylinder wall clearances need for the 2618 AL variety, the motors tend to die after a short period of time. The larger clearances just beat the crap out of the cylinder walls and rings...especially on hold start. I am not questing your judgement, I'm just saying that by using the 2618 AL, you give up quite a bit of longevity of the motor, and they also tend to burn more oil that 4032 AL. Of course, nothing comes for free, so by going with the 4032 high silicon aluminum, you give up a little bit of strength, for more longer longevitiy. And most people will only recommend 2618 for forced induction cars that are raced heavily, and not for the aggressive street usage that our cars will likely see.

In terms of noise, the biggest factor is the thermal expansion characteristics, and the clearances required. No question about that. I loose piston will make more noise than a tight one...all thing being equal. Yes, ring design, and other factors can effect the noise.

The good news is since your motor was very quite with 2618, then then 4032 should fine as well. I agree that a torque plate should be required material when building this motor. 90% of shops will send their motor out to be machined, assembled and balanced, so this usually isnt a problem...but I will make sure they have a torque plate for the VQ.

 

Kyle/Mark,

Can you tell what kind of fuel mileage the car is getting at the 8.5:1 compression? On my Greddy kit a 9psi, I getting about 20mpg average. What could I expect with 8.5:1 compression at the 750cc injectors? Any ideas?