GTR Forum banner

1 - 18 of 18 Posts

·
Registered
Joined
·
9 Posts
Discussion Starter #1
Hey folks,

So the HCC Motorsport Chrome GTR has now been finished off with:

2x GTC downpipes
Milltek Y pipe
HKS System, titanium 'Legamax Premium'
HKS Super SQV Blowoff valves

Cobb Access Port.
We have used a custom map in the end - MANY thanks to Ben from GTC for providing this - as bhp and 'smoothness' of power curve is better. Giving us 628bhp with similar torque.



So the 511 was the standard run with the above mods. The 554 was with the Cobb Stage 1 map and the 628 using the custom map provided by Ben.

Joe
 

·
Registered
Joined
·
1,726 Posts
Hey folks,

So the HCC Motorsport Chrome GTR has now been finished off with:

2x GTC downpipes
Milltek Y pipe
HKS System, titanium 'Legamax Premium'
HKS Super SQV Blowoff valves

Cobb Access Port.
We have used a custom map in the end - MANY thanks to Ben from GTC for providing this - as bhp and 'smoothness' of power curve is better. Giving us 628bhp with similar torque.





So the 511 was the standard run with the above mods. The 554 was with the Cobb Stage 1 map and the 628 using the custom map provided by Ben.

Joe
Awesome torque..I suppose next you'll will want 800cc injectors and more boost to hold it to the limit :D

Great results from a Great Thistle Map:clap: :clap::clap:
 

·
Registered
Joined
·
1,726 Posts
You'll also need a TCM remap when they crack the code :D stop the brute shutting you down just when the fun starts:bawling:
 

·
Premium Member
Joined
·
2,519 Posts
What is the approximate cost of taking a GTR to this stage?
 

·
Premium Member
Joined
·
5,031 Posts
Fantastic figures as I said in email Jon!
And on a Dyno Dynamics too, which are traditionally known as "heartbreakers", at least in the US, as they are less optimistic than many other types.

Can you detail what was on the cars at the two lower power curves?

Looks like downpipes make a huge difference.
 

·
Registered
Joined
·
1,726 Posts
Hey folks,

So the HCC Motorsport Chrome GTR has now been finished off with:

2x GTC downpipes
Milltek Y pipe
HKS System, titanium 'Legamax Premium'
HKS Super SQV Blowoff valves

Cobb Access Port.
We have used a custom map in the end - MANY thanks to Ben from GTC for providing this - as bhp and 'smoothness' of power curve is better. Giving us 628bhp with similar torque.



So the 511 was the standard run with the above mods. The 554 was with the Cobb Stage 1 map and the 628 using the custom map provided by Ben.

Joe

Just looked back at my dyno run graph and looks same shape curve just 36 bhp less but shape exactly the same just thought i'd post it for comparison. I have OEM exhaust and the only tunes i have are GTC down pipe GTC titan Y pipe and of course Custom map from GTC/Ben/Thistle.:D
http://s851.photobucket.com/albums/ab79/johnhanton57/?action=view&current=img008.jpg&newest=1
 

·
Registered
Joined
·
23 Posts
The four runs break down as:

1st - stock ECU with GTC downpipes, Milltek Y pipe and HKS exhaust

2nd - remap with Cobb mapping

3rd and 4th - Bens custom map

The car is pretty loud outside now and sounds awesome under load. Inside is ok but as with anything decatted there is a fair bit of drone emanating under the front seats which makes your ears pop in the front and is deafening in the back. This car seems to be at its worse between 2000 - 2400rpm. It will be fine in the warm weather when the windows are down.

Interestingly I never used the auto box before as it always seemed to be in the wrong gear for pretty much everything, 6th at 30mph! but now it comes into its own as 6th gear at 30mph still has lots of pull.

I will have this car on at Santa Pod next year just to see what times it gets. I have never been before but am just curious about this car. I am ever so slowly falling in love with it.
 

·
Premium Member
Joined
·
5,031 Posts
The four runs break down as:

1st - stock ECU with GTC downpipes, Milltek Y pipe and HKS exhaust

2nd - remap with Cobb mapping

3rd and 4th - Bens custom map

The car is pretty loud outside now and sounds awesome under load. Inside is ok but as with anything decatted there is a fair bit of drone emanating under the front seats which makes your ears pop in the front and is deafening in the back. This car seems to be at its worse between 2000 - 2400rpm. It will be fine in the warm weather when the windows are down.

Interestingly I never used the auto box before as it always seemed to be in the wrong gear for pretty much everything, 6th at 30mph! but now it comes into its own as 6th gear at 30mph still has lots of pull.

I will have this car on at Santa Pod next year just to see what times it gets. I have never been before but am just curious about this car. I am ever so slowly falling in love with it.
Thanks for the info Jon. Blimey 74hp gain for the GTC custom map over Cobb Stage 1 "shelf" map! :bowdown1:

Looking forward to seeing what mine will do with an Akrapovic full system (i.e. Y-pipe and cat-back) but without downpipes.
 

·
Registered
Joined
·
315 Posts
Nice results mate!! And nice motor BTW:p

I'll be aiming for those figures come Spring 2010 with a similar set up.

Planned mods:
GTC down pipes
Miltek Y pipe
Miltek rear system
Cobbs Accessport (custom map)

What about adding these as well, any point?
Forge actuators
BOVs
Induction kits/uprated panel filters (heard the R35s don't respond well to these)

What does anyone else think??

Cheers
Trav
 

·
Registered
Joined
·
23 Posts
I shall be having the bigger injectors/actuators I think!

I need it to have more fuel, we need to get the mpg down to single figures after all!!

My son says that the polar bears hate me. :-(
 

·
Registered
Joined
·
1,216 Posts
Downside is that they are a PITA to install (10-20hrs labour with many dropping the engine to do it), you need bigger injectors (or fuel pressure raise) to be able to fuel for the extra airflow (and I'm waiting for a crucial bit of the TCM work to be done to be able to release the best scaling method for injectors as it is all integrated), and on some engines/fuels you then have to retard the ignition which means you don't always get more power. Additionally, you may increase the intake temperatures too much, wear the turbo thrust bearings and risk overspeed. On top of that, the preload on many Forge installations seems quite variable. Personally I wouldn't bother, leave a margin for cool running, knock resistance, reliability and ability to track it hard, and suggest the next step is to change the turbos, and upgrade the gearbox internals - ie expensive, arguably best to stop here since it can be difficult to convert more power into more fun or better drag or circuit performance.

But ignore me, I'm notoriously miserable/pessimistic/realistic (depending on your opinion) about these things. If you asked me what your car should do on a dyno I would say hopefully over 550 BHP for example ;)
 

·
Banned
Joined
·
11,494 Posts
That's all true but you wouldn't have to drive uprated actuators with an exponential duty cycle curve. Hence it's probably safer.
 

·
Registered
Joined
·
1,216 Posts
I'd hoped that would be true, but you can go to the point where you have 1.2 bar midrange with 0% duty cycle if you have the stiffer AAM actuators, but you still need to add about 50% IIRC just to get 1.0 bar at 7000 RPM. On Forge actuators you can be over 80% at high RPM, which after all the effort of fitting is disappointing.

Since the required exponential ramp point can vary between gears and at what RPM you stomp the throttle, so it needs careful tuning in the ECU to get right, but the new boost control tables have some proportional gain that drives it towards the intended boost nicely.

On some Subarus you can have an uprated turbo with uprated actuator and just run say 50% duty cycle everywhere and it would run a nice 1.4 bar midrange, dropping to 1.3 bar at red line.

Perhaps the wastegate flappers on the GTR turbos are too big, or the exhaust housings just too small. I've not come across one with wastegate creep yet.

The GTR is odd that no matter what the actuator, you can gain substantial power from exponentially ramping the duty cycle. Messy to map but it does work. Few boost controllers work well in this situation either.

Interestingly on AMS uprated turbos with actuators, you can hold about 1.6 or 1.7 bar to red line with only 10 or 20% ramp, yet they are still on song at 3000 RPM. Much better to go this way if budget allows as they release silly power with a wide power band, although more work is needed on TCM signalling to put the whole package together to drive like OEM.
 
1 - 18 of 18 Posts
Top