Ryan.G GTR Stage XX

[Ryan.g]

After being given the pleasure to sit in a fair amount of 900hp+ R35GTRs I found that my personal 620hp Gtr was really starting to feel gutless at high rpm where the VR38DETT tends to sit when accelerating hard.

As I deal with alot of the US tuners I was repeatedly told to look at the Switzer P800 kit which they have well over 200 installations in the world! Half of which are on stock engine internals. This kind of data speaks numbers to me on a well developed product and after speaking with Tym @ Switzer more, I decided to order a set of his smaller P800 turbo’s which he classed as P700’s.

The turbo’s arrived within 4 days and to go about the installation I asked Litchfield imports who again have got a track record which speak numbers for engine and especially gearbox work. The installation was not going to be a normal one as I had 6 x Exhaust gas temp sensors to go in each running which they also had no problems dealing with as well a making a custom kit to fit my adjustable fuel pressure regulator with fuel pressure sensor.

As I was off to tune some cars over in Greece I decided to leave the car at Litchfields for the week. Ian kindly dropped and collected me from the local train station and Jenny, his fantastic wife provided me with lunch on both occasions.

Throughout the week Ian updated me on progress and provided pictures which when your car is over 1000 miles away is really reassuring.







Collection day arrived and after wiring in all the sensors into the Syvecs I took the car up to SRR to get it calibrated to suit.

Upon initially driving the car I was baffled to why Nissan didn’t fit a set of these turbo’s to start with as the transient boost driving was transformed with the lighter billet wheels and the lag seemed the same as standard! I was even starting to worry that I had stock turbo’s still fitted!

With the standard engine you need to keep a cap on the torque by limiting the boost at lower rpm but my aim was to get a flat torque curve right to the red line. Here are the results for 1.1bar rising to 1.3bar at top end.




Spec:
Switzer P700 Turbo’s
GTC 76mm Intakes
Whifbitz Titanium Silenced Y Pipe
Whifbitz Downpipes
ID1000 Injectors
Syvecs S8

Everything else on the car is stock including the Intercooler and Back box

Some of the EGT and Pre Intercooler Data is rather interesting! With the new turbos the pre intercooler temps have actually dropped at high rpm with a more efficient compressor wheel.


Here is also a graph comparing the same spec but with the standard turbo’s running 1.2bar



Ryan

[Adamantium]

Ryan,

am I right in saying you are 80lbft down at 2700 rpm.

You say the spool is comparable but surely that will feel slower at the bottom end?

[Ryan.g]

Originally Posted by Adamantium

Ryan,

am I right in saying you are 80lbft down at 2700 rpm.

You say the spool is comparable but surely that will feel slower at the bottom end?

From 3000 - 4700rpm i am planning on turning the boost up to 1.2bar like the stock turbos were running to push the torque up slighty but i was more interested in getting lots of data on EGT and Pre/Post intercooler temps to work towards a more aggressive map. Plus will be honest and say i rarely get any time to work on my own stuff and this was done in between a customer dyno session while the customer was fixing his oil leak

But yes you are correct at 2700 it is 80ftlb down.... but how often in auto mode or even manual mode will it be accellerating from this Rpm..... Never

[Adamantium]

I suppose so, but still nice to be higher up than the old set up at all points.

Can I ask, does your testing back up the suggestion that changing the intercooler at the same time as the turbos is really beneficial?

[Mark@Abbey M/S]

I suppose so, but still nice to be higher up than the old set up at all points

As Ryan said you never drive at full throttle in 4 or 5th gear at 2700+ rpm , throw the dyno plot in the rubbish bin, drive the car, it will be fun.

I am in the opinion that running larger turbo's like Ryan's and run less boost pressure to run the BHP your lower the charge temps so a larger intercooler wont be needed.

Looking good thou Ryan.

[vxrcymru]

Originally Posted by Mark@Abbey M/S

As Ryan said you never drive at full throttle in 4 or 5th gear at 2700+ rpm , throw the dyno plot in the rubbish bin, drive the car, it will be fun.

I am in the opinion that running larger turbo's like Ryan's and run less boost pressure to run the BHP your lower the charge temps so a larger intercooler wont be needed.

Looking good thou Ryan.

Would the car feel as fast as a 710 ish car with a larger intercooler tho I suspect there would have to be compromises somewhere?

It would be great if cars could run this sort of power without spending 3k on intercoolers.

[vxrcymru]

Originally Posted by Ryan.g

From 3000 - 4700rpm i am planning on turning the boost up to 1.2bar like the stock turbos were running to push the torque up slighty but i was more interested in getting lots of data on EGT and Pre/Post intercooler temps to work towards a more aggressive map. Plus will be honest and say i rarely get any time to work on my own stuff and this was done in between a customer dyno session while the customer was fixing his oil leak

But yes you are correct at 2700 it is 80ftlb down.... but how often in auto mode or even manual mode will it be accellerating from this Rpm..... Never

Whats the price of these turbos compared to say a turbo dynamics system?

[Adamantium]

Originally Posted by vxrcymru

Whats the price of these turbos compared to say a turbo dynamics system?

Good question!

[charles charlie]

Forgive my ignorance on this as I never see many dyno charts, but doesnt that show these turbos are down on both torque and power until only after 4700 rpm?

To me that looks like worse than OEM for all road situations unless you are on full OWT and looking to go to the redline. Wouldnt that mean you're actually running less than OEM turbos for probably 80-90% of driving situations?

I personally wouldnt want extra up top for such a reduction down below. Maybe more grunt mid range is a better result no?

Apologies if I've read the graph wrong btw!

[Anders_R35]

I think the graph looks pretty good given the extra power up top, will the car be quicker in a 1/4 mile or on track...yes. And perhaps not a fair comparison until the same boost is run on the new turbos.

[Ryan.g]

Originally Posted by vxrcymru

Whats the price of these turbos compared to say a turbo dynamics system?

You would need to speak to Switzer for that answer.

SWITZER | Performance. Innovation.

[Ryan.g]

Originally Posted by vxrcymru

Would the car feel as fast as a 710 ish car with a larger intercooler tho I suspect there would have to be compromises somewhere?

It would be great if cars could run this sort of power without spending 3k on intercoolers.

For a Road/Drag Car i see no data from the S8 that would suggest you need an aftermarket intercooler. As said the pre intercooler temp are lower which is an improvement.

I can not comment yet for a Race track session.

[grahamc]

Subscribed.

Been waiting for this

[Ryan.g]

Originally Posted by charles charlie

Forgive my ignorance on this as I never see many dyno charts, but doesnt that show these turbos are down on both torque and power until only after 4700 rpm?

To me that looks like worse than OEM for all road situations unless you are on full OWT and looking to go to the redline. Wouldnt that mean you're actually running less than OEM turbos for probably 80-90% of driving situations?

I personally wouldnt want extra up top for such a reduction down below. Maybe more grunt mid range is a better result no?

Apologies if I've read the graph wrong btw!

You have not read the graph wrong but its only down to 4200rpm.. after this point it is the same or more....but as said above it is running less boost compared to the stock turbos at below 4000rp as i wanted to achieve as close to a flat torque curve from 4000-7000rpm as possible.

Also too much torque low down running close to the Knock limit is a killer on the Rods for these engines as it only takes one large ping of knock at this point in the combustion chamber where the cylinder pressures are at there highest and you have done damage so with new parts like this data is taken... overserved and then put into the application next time i have some free time on the dyno.

Accelerating hard though and under no up shift does it drop below 4200rpm so the car feels a fair bit faster with all the extra torque.

[grahamc]

Ryan is the comparing to your car 620bhp? Maybe a better comparison is completely stock...