R32 GTR EFR 7670 Build

[Dievos]

This build was primarily started  to alleviate the issue of having too much lag for a street car, in 2012 I had replaced the factory twin turbos with strengthened RS581 LeMans turbos. This turned into a bit of a mistake as I found the power delivery to be very linear and the car was incredibly doughy at low RPM. At the time I was very unaware of what a responsive twin turbo RB26 should feel like and I just accepted the lag as the car was making more power.

The budget of an EFR setup has been a huge obstacle for me and as the years have gone by I have finally assembled and decided what is the best combination for my needs. 

 

 

My power limit of 300-350kW would rule out the EFR 8374 which was what I had been setting my sights on - but being greedy for more response drove me to the 7670. I also wanted the build to be simple and less complicated which is with I went with the IWG option.                                                                                                                        

The last purchase I made was for the turbo and I wanted to get straight into it - I didn't want to wait and give my money to a garage to fit everything up, it was also my first real overhaul on any car but decided to hack away at it and give it a go.

Conditions were not perfect, I had to remove the twins and all the factory hoses and piping, this was done outside after work so I only had a few hours of daylight each day.

Starting from the top was a good approach and everything with a nut or bolt was loosened and removed  to declutter and improve morale on the task ahead.. 

 

More and more parts had to come off the car which was daunting to begin with but everything had a bag to go in so I could be reassembled without any headaches, the A/C was also completely removed while everything was off.

 

After many short frustrating nights I finally had the twins out and could start mocking up the fitment and how everything around the turbo was going to run.

 

Immediately I thought shaping and welding sections of intercooler pipe would be the way to go with the plumbing for the turbo.

 

Weather kept packing in and progress was delayed so someone kindly let me in to a hangar to make up for the time lost.

 

 

All the recirc and blow off valve parts were removed to rid the car of dead weight.

Plenty of progress was made while I could work in here and also while removing the old recirc piping I found that it would be a perfect fit and bend for the turbo and would subsequently save me a heap of time instead of an intercooler pipe fabricated to do the same job.

Knowing that the factory actuator could potentially cause problems with boost control it was swapped for a Turbosmart IWG75 twin port actuator.

Turbo was off and on more times than I could count to get everything torqued down and hose lengths and the p/s reservoir lines to fit up tidily.

 

After everything was fitted and tightened down I removed the plugs to crank the engine over and confirm the oil flow for the turbo feed. After a few cranks the new oil started coming out and could be attached to the turbo. 

 

As the blow off valves were also removed and a cap was made for the hose. It would holt 20+psi better than a WD40 cap!

The downpipe posed to be one of the biggest problems as no one in my area would supply or create pre-bent 3.5" stainless tube. I had to purchase a 3.5" stainless donut from sinco to sort out the rest of the exhaust. This was an absolute nightmare to cut.

More and more small parts started to become apparent to me that I'd need to finish everything off and after a bucket load of invoices and receipts I finally had everything I needed. Most of my time was spend running back and forth from the shops to find the correct fittings, hoses etc. - rookie stuff.

 

Everything started to take shape at this stage and I was very happy on how simplified I made the engine bay. Boost control and blow off valve lines were sorted after this and the engine bay had a general refresh.

No leaks were discovered and the car has since been waiting for a dyno tune.

                                                                                                                                                                                                                                                                                             

Edited October 20, 2017 by Dievos
grammar, remove unwanted picture.

[Mick_o]

Nice write up mate thanks for sharing! 

This will be a cracking little setup! 

Something ive looked forward to seeing somebody do as this as an alternative to a -7 or -9 power range but will absolutely knock them out the park for response and driveability.

Proof that you dont just go single because you want a million hp GTR!

So the car will be on 98? 

How long till shes tuned? Looking forward to seeing how she goes ?

[Dievos]

Cheers for the words mate, 300kW+ is plenty for me and making it quickly will only make me happier.

You're right - will be using 98 for the tune. Should be going on the dyno this Wednesday, excited to see what results I will get on a standard engine.

[Mick_o]

The 1.05 rear would of definately helped your cause on 98 with only a couple hundred rpm sacrifice  (that you probably wouldnt have noticed due to a lil more off boost torque filling the void) but obviously would have been a much more expensive exercise.

Im gunna take a punt and say this set up will be more responsive than the stock turbos and make more power everywhere and 100kw more than the stock turbos. 

Again using bro science i expect this thing to start getting rapid around the 3500 zone in early gears. 

Keep us posted and see how far off the money my predictions are haha! ?

[T04GTR]

thats mad. instant boost. but do yourself a favor and cut the "divider" part of the gasket out or find a mls single entry gasket. as all the t4 dual entry "gasket leaks" ive fixed are because of the divider.

the divider wall is the hottest part of the housing and "grows" more than the periphery, constantly lifts on the divider and eventually lifts enough to break the seal around the outside of the flange. the oxy cuts the gasket away leaving a nice section missing but the divider perfectly intact..

[Dievos]

Such a tease. Guess we'll have to wait and see tomorrow...

 

[Mick_o]

Good luck today! Watching this like a hawk! In for results! ?

[RATM]

Cant wait to see dyno result!!! Considering buying this turbo for my rb26 as well

[Kinkstaah]

I have this turbo so a vested interest on how this turns out [emoji14]

[Dievos]

Firstly, I'll say that the results were a bit inconclusive. We had real issues with the nuts on the actuator coming loose and being a general pain to adjust midway through testing. It was a rookie mistake from me in the first place to not set the preload accurately. We ended up double nutting the actuator to secure it in place, where it ended up being set was quite low and effected the spool by a fair margin. This is what we ended up with:

From here I will adjust the preload on the turbo correctly but I'm expecting it to have a massive impact on the spool. What I found interesting was how things were out of breath around 6500rpm. Can anyone here say that standard cams would be the issue here - seems odd for that to happen so early. Valvetrain getting tired perhaps? 

 

This run was done on 21psi. The green trace is was the old setup with the LeMan turbos on 1.6bar and and red trace is the EFR.

Off the dyno the car feels awesome to drive and along with the baby T51R sound I rarely see myself going over 5000rpm because of the torque.

 

[R377]

Out of breathe ? what fuel pump, injectors and coils are u running ?

[fatz]

same turbo on a mates car ran 270rwkw and dies in the arse after 6k

 

so you on the money

he upgraded to the nxt size up and was much happier

[Piggaz]

9 minutes ago, fatz said:

same turbo on a mates car ran 270rwkw and dies in the arse after 6k

 

so you on the money

he upgraded to the nxt size up and was much happier

But yet they go 380-400 quite comfortably on 4G's. ?.

Need to bin the IWG and Externally gate it. 

[Kinkstaah]

IWG versions of most EFR setups have proven to be a bit disappointing.

Don't forget this turbo has a rear end wheel bigger than a gt35, it will always be 'laggy' its a pretty big turbo, not being able to spin it up due to gate issues (or 98) will take the wind out of it.

[fatz]

 

19 minutes ago, Piggaz said:

But yet they go 380-400 quite comfortably on 4G's. ?.

Need to bin the IWG and Externally gate it. 

Yup

but if ya want to party at targa this is the price you pay 

[blah_blah]

Following this thread with interest

[Dievos]

It's still a bit early to say that it's a disappointing result.

This is what we have also mapped.

 

I'm still puzzled at what might be causing the drop off at 6500rpm, it doesn't look like an ignition problem judging by the trace and the boost still holds fine.

[fatz]

It cause the rear housing is choking like a bad porno

keep chasing the known problem or upgrade

 

 

[fatz]

Should also say in America where all the epic numbers come from their ponies are smaller than the rest of the world so this may also lead to disappointment cause it didn't make 400kw

[Dievos]

Could be the case, a little hesitant on calling it that as the last setup dropped off in the exact same place