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Discussion Starter #1 (Edited)
Thought its time I did a project build thread, as the GTR has now really come along along way since 2012..enjoy the read :)

Purchased my R35 GTR back in September 2012, had 2100 miles on the clock from Ancaster.

5 days later, went to Stelvio Pass with a friend in his Porsche 997 Turbo; writeup here (2300miles in 3days) :D epic trip! :)

A few days after collection:







Was quite happy with the overall package, did a few trackdays, and realised the brakes, weren***8217;t great on track, and gearbox temps started to spike. Reading a lot of threads on modifications etc, and it then slowly begins***8230;:eek:

March 2013

So after some research and when the 1st service was due in march2013, I opted to go to Litchfields, carry out the service, along with adding a few mods :

Going to stage4 (keeping OEM downpipes), air intake, injectors, ecutek remap -v3?).
Exhaust I chose the Akrapovic evolution system, titanium lightweight, 90mm, and carbon tails.
I also went with the HKS DCT gearbox cooler to help keep the gearbox temps cool.
I had read great feedback on the newly revised Alcon Superkit system, so that was added to the list too. The OEM brakes needed to be replaced soon, so opted for the superkit.
I also ordered one of the first set of Rays VR G25 alloys in the uk, in Formula Silver - 10j & 11j - saw the pics from Tokyo AutoSalon show and loved the design. Michelin Pilot Super Sports had just been released.





Tyres and alignment carried out by Sly :



Went to the SPA race track, end of March 2013, and it was very cold, first day was good - dried out after lunchtime and it was getting better and better.
Second day it had snowed heavily overnight, and it was cancelled!

first day :





second day : view from the hotel



Went along to a dyno day, at a local MAHA place - (before Litchfields had their dyno cell).



stage 4 (no dps) - 661hp/610lbs





August 2013 - Drive to Swiss & Italian Alps:

On a long weekend, went to the Alps and tried 10 of the mountain roads listed here Ultimate Drives, including going via Black Forest.



A cheeky pic I couldn't help stopping and taking. :)



Following this, I saw the Mercury Silver versions had come out of the G25s, hence soon ordered a set, as I felt they'd look better against the Daytona Blue.








January 2014

Time to address the interior and I felt the OEM seats weren't great when on track, as you tend to slide too much.
Following the TAS show again, ordered the following from [email protected]:
Top Secret Steering wheel - Top half blue carbon, rest in leather.
Top Secret Front diffuser
HKS Kansai side skirts
Bride Cusco Stradia Seats

Also ordered from the US, Titan motorsport halfcage, as I wanted to add Schroth 4pot harnesses, without using the rear seatbelt mounts.
Fitted the above myself over the course of a few evenings after work, as I wanted to take my time and ensure everything was good.









March 2014 - Another SPA weekend

First day was great, nice and dry sunny weather, but on the second day, around lunchtime, the 4WD locked in 4drive mode, and thus the front differential decided it didn***8217;t want to play anymore.. and disintegrated.
Cue B.A Barry Baracus :D

Sly took the gearbox apart and lifted up the engine and replaced the diff with a brand new OEM diff (no quaife***8217;s available then), AWD shipped to Litchfields who repaired, upgraded and shipped it back to Sly.







Sept2014 - PWPro
Went to [email protected] for some cosmetic TLC

March2015

Service and Ecutek v5 update at Litchfields, stage 4.25 with 102mm exhaust system result 680hp/634lbs

Dyno plot :




August 2015

Went to Litchfields and upgraded to the Log Manifolds with EFR 6758 turbos, and standard engine/gearbox



Dyno plot: 801hp/634lbs



September 2015 - SPA

Was great, had a chance to test out the Cup2s on my G25s 265/35/20 & 305/30/20s, played around with different pressures, but just couldn't get to grips with them. For road driving they felt better than the MPSSs, but on track, I missed the Toyo R888s, which give alot more grip and confidence.

Drive back with some Stuttgart chums:



March 2016

Service and ecutek v5 update, bellhousing replacement too, Toyo's R888Rs added, aswell as Alcon ccx brake discs and pads.
Steering feel and input was completely transformed, no longer heavy, and the slightest turn would incur an immediate response.. Takes a while getting used to this, as way less steering input is now required.

Dyno plot :




Donnington Trackday






September 2016

Silverstone Trackday, going well till about lunctime, when I had issues with the gearbox, plugged in the ecutek cable and diags said actuators were fault C1205/1206 errors.
Car still drove and gears changed ok, decided to drive the car over to Litchfields, to get it sorted.
They checked it and said the gearbox needed to be dropped and opened up, which would take alittle while, due to other cars being booked in etc.

Winter 2016/2017

Started to think about engine upgrades whilst it was still there, and after speaking with Iain, opted for the LM 3.8 Rods/pistons, along with throttlebodies, inlet manifold, new engine oil catchcan option, and gearbox upgrades, Dodson 1st gear with upgraded circlips, 2/4/6th shaft upgrade (original one had signs of heat spots).

Dyno'd at 908hp/678lbs - 1.6bar 916hp, the dyno plot below also shows the previous stg 5.5 before engine mods.



A few engine pics :

before inlet manifold



After now with inlet manifold and larger throttle bodies.



Should be almost completed finished shortly, Iain also fitted an inline electric oil pump to aid the transmission oil pump. This can be toggled on/off when at the track.
Also looking to add some brake duct cooling front and rear to aid the ceramics to cool quicker. Heard alot of stories of Porsche ceramics glazing due to lack of cooling on track.

=============================================================================================================================

Mods:

Power

LM 3.8 Engine build, with Custom Forged Piston set with new Piston Rings
Litchfield GTR Custom Forged Connecting Rods
ARP Main stud bolt kit
Balanced Engine internals and Crank balanced
Dodson engine seal plates
Modified water pump
BorgWarner EFR 6758 turbos, with Litchfield manifolds, uprated wastegates, injectors, uprated fuel pumps, air filters etc
Litchfield Dominator Race intercooler
102mm Full SS system (triple silenced)
LM Oil Catch can twin setup

Ecutek v6 Racerom and TCM maps dyno***8217;d at Litchfield at 916hp/673lbs torque.

Gearbox / Transmission

HKS DCT Gearbox transmission cooler
HKS Gearbox transmission oil sump pan
Uprated Gearbox Circlips & magnets
Litchfield uprated Bellhousing
Dodson 1st Gear
Uprated 2/4/6 shaft

Brakes & Chassis

Alcon CCX superkit - with stainless steel lines.
Quaife front differential
Litchfield Suspension with Eibach front & rear ARBs
Litchfield Road Handling kit

Wheels

Rays VolkRacing G25s (formula silver) with Toyo R888Rs tyres
TSW Nurburgrings with MPSSs tyres (with tpms)

Interior

Top Secret steering wheel (blue carbon top half, rest is full leather - flat bottomed)
Titan Motorsports half rollcage (matt black) - no cutting of interior panels/seats required.
Bride/Cusco Stradia II Low Max tilt bucket seats with sliding rails. These sit 20mm lower than oem seats, and more than half the weight saved!
Schroth 4pt harnesses (blue) - 3***8221; shoulder / 2***8221; lap belts.

Exterior

Full Paint Protection film on complete front and rear half quarter panels (via pwpro/paintshield)
Top Secret carbon fibre front splitter & diffuser (full cf underside) - not a replica!
HKS Kansai carbon fibre side skirts (perfect fitment)
Carbon fibre rear valence

=============================================================================================================================

Big Big Thanks to Iain and his team:bowdown1: this has really been an awesome project, modding is real addiction.
I'm really pleased I've been able to help make the mighty GTR into an real epic monster.

:flame:

Thanks for reading! :smokin:
 

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Nice build thread tin, that's the spec I'd like, bet that goes really well!
Did the LM inlet manifold and throttle body's make a big difference?
 

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Discussion Starter #5
Excellent thread. Car looks superb.

More photos please :)
Will get some once its back and all polished up. Silverstone next month :)

Nice build thread tin, that's the spec I'd like, bet that goes really well!
Did the LM inlet manifold and throttle body's make a big difference?
Massive difference, if you look at the latest dyno plot, there are increases everywhere, flat torque curve all the way to 7600rpm. The power is made earlier too, and this is also still on vpower fuel.

Hopefully will hook up the vbox and get some times, and take a trip over to Santa pod too. :)
 

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Nice build thread tin, that's the spec I'd like, bet that goes really well!
Did the LM inlet manifold and throttle body's make a big difference?
Massive difference, if you look at the latest dyno plot, there are increases everywhere, flat torque curve all the way to 7600rpm. The power is made earlier too, and this is also still on vpower fuel.
Hopefully will hook up the vbox and get some times, and take a trip over to Santa pod too. :)
Nice writeup chap! The EFR 6758's really kickin ass there! 900bhp on them is superb!

How did you find the car power and spool, when moving from stage 4.25, to then 800bhp / then 900bhp...

also how much was the inlet manifold and throttle bodieS? Can't see the prices on the website (only with turbos)..

looks like you have had a fun along the way bud.... Congrats! :thumbsup:
 

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Progressive dynos really help to show the turbos boost threshold.

Stock turbos with downpipes and no cats, at wide open throttle still not producing as much torque as soon as the full manifold 6758 but then still going on to 900 bhp.
 

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Discussion Starter #8
Nice writeup chap! The EFR 6758's really kickin ass there! 900bhp on them is superb!

How did you find the car power and spool, when moving from stage 4.25, to then 800bhp / then 900bhp...

also how much was the inlet manifold and throttle bodieS? Can't see the prices on the website (only with turbos)..

looks like you have had a fun along the way bud.... Congrats! :thumbsup:
Thanks, am really pleased with the results, Iain said it made 925hp, but dialled the timing back to make it safe.

The jump from 4.25 to 5.5 is huge! power delivery is so much more linear and not the snappy kickback you used to get from 3.4k and then fizzling out at 5.8k. Just consistent pull all the way to 6.8k.

It's currently at Litchfields, just finalising bits, hence have not driven it, in its current form.

Can't wait though!:flame:
 

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you've invented a new one there.

Stage 4.5 was a halfway house turbine upgrade on the stock frame turbo. (hybridised)

Stage 5 was always a new non-stock frame turbo and ancillaries ie. no need for .25 or .5.

I think we are getting to the point where we need to define the stages as confusion is now setting in.
 

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Discussion Starter #12
I thought stage 5 was turbos, but without any aftermarket manifolds or intercooler, hence 5.5 with manifolds and race intercooler.

It does get confusing from 5 onwards though! :)
 

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.25 usually means downpipes or intercooler (pre stage 5), they can't add together as that would give .5 which stands on its own as an aftermarket hybridised turbo.

Stage 5 always included downpipes as non stock frame turbos need new ones regardless.

I guess 5.25 could have existed as it would mean intercooler.

It's much easier beyond stage 4 to just list the major mods.

Either way, your thread, so your choice. The car looks amazing, probably a real sweet spot for those who want to go beyond 4.25 (ugh) but not go wild.

I think many of us would like feedback on the gearbox mods as they are probably the parts few people have experience of.

Why did you choose this step, what's the benefit and cost and why did you not go further with the gearbox.

You've also limited torque on a forged engine, is that because of the gearbox?

If you have strengthened 1st gear, could you have a higher torque limit in 1st or is it unnecessary?
 

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I think many of us would like feedback on the gearbox mods as they are probably the parts few people have experience of.

Why did you choose this step, what's the benefit and cost and why did you not go further with the gearbox.

You've also limited torque on a forged engine, is that because of the gearbox?

If you have strengthened 1st gear, could you have a higher torque limit in 1st or is it unnecessary?
Arn't R35 stock gearbox's good for around 750lb ft.. I thought the torque was restricted due to the Rods in the engine. So as its forged, Tin should be good to go to up the torque...
 

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Nice write up tin, the car is lovely to drive. Just looking at the brake ducts now :thumbsup:

Tin's car will do a lot of extra torque and we have pulled timing out from the original tables to reduce it so a sensible level for the gearbox. It only runs about 1.2bar low down to achieve these figures and the new short engine is clearly working well low down. It made ~700lbft with the same ignition and boost as the previous tune. Higher up the rev range the inlet manifold and throttles really come into their own and give a nice wide power band.

Adam, we do offer a Stage 5.5 (it's listed on the Tiered upgrade table PDF but will be on the website soon). If you add our manifolds and race intercooler it will make 775bhp at less boost so its become a popular upgrade for customers that may decide to go with a full engine build later down the line.

Regards

Iain
 

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It made ~700lbft with the same ignition and boost as the previous tune. Higher up the rev range the inlet manifold and throttles really come into their own and give a nice wide power band.

Regards

Iain
Iain,

Can you clarify that comment so that I fully understand it.

You just changed the engine from the stock block to your basic forged 3.8 short engine, and on no intial change to the map it made 700lbft?
 

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Adam, the engine will be making more power on its own as its more efficient i.e compression ratio is different, squish is adjusted, valve seats are cut, piston crown is different, rings everything will have an effect. On Tin's car we added the inlet and throttles which will also change its power so I can't say how much comes from what part.
 

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Discussion Starter #19
Thanks for the additional info Iain :)

I didn't choose to go all out on a built gearbox, as reading other build projects and feedback from others, a built gearbox has alot more noise & clunkyness at lower speeds etc.

My primary concern was to fix the initial gearbox actuator issue, and whilst the car was there over winter, it was the perfect time to get the engine mods done. I don't tend to drive it during the winter as I have other cars which fit that better.
I also had been running the previous stage 807hp for nearly 18mths and didn't want the engine to go bang.
Paying out for a new engine, only then to forge/strengthen get extremely expensive. :eek:

If the gearbox goes bang, the cost is the same regardless when uprating.

I'm hoping to do alot more trackdays this year, hence wanted the car to be 100%.

A few more tweaks left, also have a set of MY16 lights to go on, and possibly a set of 12J rear wheels, as 345 cup2s may be better suited now, than the 315 r888r.
Will try a couple of trackdays and see how the added power and road handling kit is.

Had a few pm's asking about the build etc. :thumbsup:

This is now definitely a keeper for me, No.2 in the collection, unless a silly ridiculous offer came along!:chuckle:
 
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