Doing a +t conversion on an unopened RB25DE NEO (R34 GT)

[nismo_d'luxe]

Not to be "that guy" but I've got an n/a neo thats looking at being replaced by a turbo neo in the next 12 months....regardless of the engine everyone seems to get great results from turbo'ing n/a motors but it seems to be the general concensus that they pretty much turn into hand grenades if you choose to go down this path...so my question is how many km's have you done since your de+t and how hard do you drive it? My skyline is my toy so I treat it mean but am fairly scrputenous on maintenence. I personally think im far better off dropping an already turbo'd neo motor into it...what is your oppinion? I want something thats going to last as opposed to a better low end torque curve.

[DatsunBanana]

For me doing this will be about the cost and the challenge. On the forum you'll find other threads including 666DAN's thread which (if you enjoy a lengthy read) shows that some guys ran conversions successfully long term. Parts have cost me a third of the price of the cheapest NEO DET engine. If you want bigger power then an original DET engine has way more potential. There's lots of info about taking the right precautions to stop them blowing up - hopefully it's right :-)

If you can afford it and potentially want to chase bigger power in future then you're probably doing the right thing dropping a motor (and ECU) in. You'll probably want a matching gearbox too if you want longevity.

[nismo_d'luxe]

Cant you piggy back the manual ecu's anyway? I only just read this the other day so perhaps its bullshit. I didnt think the gearboxes were any different between a turbo & non turbo 34 except perhaps the ratios, I was thinking gtr syncros though cuz I know the syncros in those boxes suck ass. I will be chasing a diff though, 4.11 is great but not for high speeds. If I can run 300kw eventually I will be happy, im only aiming for about 200 at the wheels at the moment though so I can get used to driving some proper power. Cheers for the info ill have a read

[hey_aleks]

Not to be "that guy" but I've got an n/a neo thats looking at being replaced by a turbo neo in the next 12 months....regardless of the engine everyone seems to get great results from turbo'ing n/a motors but it seems to be the general concensus that they pretty much turn into hand grenades if you choose to go down this path...so my question is how many km's have you done since your de+t and how hard do you drive it? My skyline is my toy so I treat it mean but am fairly scrputenous on maintenence. I personally think im far better off dropping an already turbo'd neo motor into it...what is your oppinion? I want something thats going to last as opposed to a better low end torque curve.

I did the conversion because I knew my de had genuine kms and being an auto it most likely hasn't seen a hard life and I wanted to get some hands on experience on our engines. After finishing the conversion, I made sure to check the garage floor for leaks before/after going for a drive and went under the car every few drives to check for anything unusual. Ive also never driven the car without having the nistune gauges displayed on my laptop just incase a fault is raised or something looks out.

There are a few things to consider before you make your decision.

I've done around 6000 kms after completing the conversion. I am an extremely spirited driver so the car is definitely not granny driven. I am fully prepared to have to drop a DET in Incase something fails which is why I try and push the car to see how it handles the conversion. The hardest few days it's seen is when I did 4 hours of constant driving over 2 days in 30° weather. The oil drain from the turbo half popped off because I didn't fully tighten the clamp. Fixed this in 30 mins at home so that would come down to user error.

To be honest, selling the car and buying a genuine manual turbo is always the best route. When it comes to resale, people don't want de+ts or manual converted skylines. Dropping in a DET is a good option as well and won't really effect resale as long as all of the Na parts on the car are replaced with gtt parts.

The thing about my 34 is that I'm too attached to let it go. Even in Na/Auto form, I was hooked the second I bought it. I'm the first person to hit boost/shred rubber in it which is an awesome feeling.

All that aside, reading the workshop manual and modifying the car myself has given me an unbelievable amount of knowledge. I cringe when I think about myself 3 months ago, barely being able to install a boost controller or wire a headunit. I still feel like I dont technically know much but I am now able to diagnose be plenty of issues and replace/upgrade parts on my own.

[jap4lyf]

47 minutes ago, nismo_d'luxe said:

Cant you piggy back the manual ecu's anyway? I only just read this the other day so perhaps its bullshit. I didnt think the gearboxes were any different between a turbo & non turbo 34 except perhaps the ratios, I was thinking gtr syncros though cuz I know the syncros in those boxes suck ass. I will be chasing a diff though, 4.11 is great but not for high speeds. If I can run 300kw eventually I will be happy, im only aiming for about 200 at the wheels at the moment though so I can get used to driving some proper power. Cheers for the info ill have a read

the n/a gearbox is the smaller rb20 type gearbox with a  push type clutch, turbo r34's come out with a much stronger and physically larger gearbox that has a pull type clutch.

[hey_aleks]

Cant you piggy back the manual ecu's anyway? I only just read this the other day so perhaps its bullshit. I didnt think the gearboxes were any different between a turbo & non turbo 34 except perhaps the ratios, I was thinking gtr syncros though cuz I know the syncros in those boxes suck ass. I will be chasing a diff though, 4.11 is great but not for high speeds. If I can run 300kw eventually I will be happy, im only aiming for about 200 at the wheels at the moment though so I can get used to driving some proper power. Cheers for the info ill have a read

I'm pretty sure de boxes have the strength of an rb20 box. I was going to originally put a 20 box in after I turbod mine since people say it should be able to support around 200rwkw if not tracked but picked up a det box for cheap. Youll be able to achieve 200rwkw easily even with stock bits and if you've been driving it n/a, the power difference alone will keep you satisfied for ages.

[nismo_d'luxe]

Yeah righto, so pretty much all the running gear needs replacing. That sucks ass, might try find a wrecked 34 gt-t for cheap or just trade mine up

[DatsunBanana]

Yeah, these are good points Aleks makes about changing over other DET bits too and there's a lot of those. NAs won't necessarily have extra bits like traction control, hicas, lsd. The suspension, brakes and fuel pump will be different (R34 NA suspension is same as R33). Have you upgraded your brakes and suspension first - or at least plan to do at the same time? These are all pretty important for the extra power and add to the cost which might make selling and buying a GTT a more economical option. Fortunately I did all that ages ago and got very good deals on the parts.

Edited November 12, 2016 by DatsunBanana

[nismo_d'luxe]

I can tell you I do have hicas & an lsd who wants traction control anyway f**k that haha. I was going to go to a walbro 255lph pump, nismo 550cc injectors, nismo s-tune suspension (coil-overs to stiff for roads out here) and r33 gtr brembos running on 245/35/18 possibly nankang rubber (cheaper and still perform well when hot), splitfire coilpacks (thats a given) run a 3 inch turbo back exhaust with a deleted cat and a 3076r steel wheel ball bearing turbo, front mount trust intercooler with twin thermofans (no clutch fan). I am fairly capable behind the wheel but by no means a racecar driver, this thing will be pushed well above 200km/h so it needs to handle and perform well.

[DatsunBanana]

Ah yes, another good point - exhaust. Forgot that as I already put a stock GTT cat back on a couple of years ago. Great that you have LSD - I want one. Mine had none of the nice options LOL. Hicas delete seems a popular mod anyway so probably not a make or break if you have it or not really.

Be interesting to see what cost estimates all this comes to for the various options. Mine's definitely been a budget build. Apexi suspension, GTT exhaust, R32 GTR brakes came in at 350 GBP. All the turbo bits are on target to come in at around 5. Just a turbo motor would have cost me £1500 GBP minimum. To sell mine and buy a GTT might have cost me 3-4K at GB prices but would probably have managed to get a manual for that.

Edited November 12, 2016 by DatsunBanana

[hey_aleks]

Ah yes, another good point - exhaust. Forgot that as I already put a stock GTT cat back on a couple of years ago. Great that you have LSD - I want one. Mine had none of the nice options LOL. Hicas delete seems a popular mod anyway so probably not a make or break if you have it or not really.
Be interesting to see what cost estimates all this comes to for the various options. Mine's definitely been a budget build. Apexi suspension, GTT exhaust, R32 GTR brakes came in at 350 GBP. All the turbo bits are on target to come in at around 5. Just a turbo motor would have cost me £1500 GBP minimum. To sell mine and buy a GTT might have cost me 3-4K at GB prices but would probably have managed to get a manual for that.

Nice buy for $580AUD, I still need to install my 33 gts-t brakes. That's $2500 for a turbo engine in the UK wtf??? We have Facebook groups where people sell import parts, I've seen rb25det motors without Bolt ons for $900 - $1200 and full rb25det engines for $1100 - $1500 with compression tests. Maybe you could look at getting a manual setup shipped to you? I have no idea how much shipping would cost but it might turn out cheaper. You can buy full conversions for around $1300 - $1800 using an r33 gearbox. I can find you parts if you ever decided to, these are AUD prices btw.

[DatsunBanana]

Yeah thanks. It's a bit mad what we have to pay for some stuff. You could get Skylines from Nissan dealers new in AU right? We only have imports (apart from a small number of GTRs) I've just waited patiently for the right deals to come along on secondhand parts. Some of the cheaper engines on eBay are without turbo and other ancillaries and then another time you'll see one with a gearbox for a couple of grand. It varies but you can see one of the reasons why I've gone the +t route on the NA engine.

[nismo_d'luxe]

Never saw the point in a catback personally, what is the point in 3 inch cat back exhaust if you have 2 inch restricting the exhaust gas flowing between the exhaust manifold & the cat? But perhaps im wrong. Hicas delete is great if you want to drift but I like high speed cornering so im sticking with the hicas. Im expecting at the end of it all to have pretty much been able to buy an rb26dett which im also well and truly considering

[hugh jaynous]

You guys are all lucky in terms of costs for this conversion haha. the cost of a good condition det motor in Canada is at the very least 1500+ and potentially double for the manual tranny attached.

The cost of me swapping to a gtt in better condition than my current setup is also gonna set me back 3-5k at least assuming I can get market price 10k and a decent gtt for 13-15k.

I honestly also feel the same way aleks feels about the car, in that I also pretty much wanted to learn and loved the car before the conversion talks. the exhaust part I also got done essentially subbed the original exhaust stuff a little in front of the cat to a 2.5 all the way through to a borla muffler at the end car sounds mean but quiet enough while crusing.

[DatsunBanana]

Heads up for anyone reading this thread and looking for a DET ECU there's a couple on yahoo auctions Japan at the mo ...

A manual currently at 2000 Yen and an auto at 6000

http://page17.auctions.yahoo.co.jp/jp/auction/v478256366

http://page4.auctions.yahoo.co.jp/jp/auction/d209093120

 

[hugh jaynous]

Those prices are amazing.

[DatsunBanana]

Aleks, just looking at the position of the nuts on the exhaust manifold. At least one seems impossible to get at with a socket. How did you manage?

[hey_aleks]

Aleks, just looking at the position of the nuts on the exhaust manifold. At least one seems impossible to get at with a socket. How did you manage?

Those prices are amazing.

It looks like the bolts are hard to undo but it's not too bad. I think I used a socket for all but one or two, used a spanner for those instead. The hard bit is cracking the bolts then most of them came off by hand, not sure if it's the same for yours but let me know how it goes [emoji106]

[DatsunBanana]

OK - that makes sense. For the last few weeks I've been regularly spraying WD40 on all the bolts/nuts I'll have to undo for this project. Hope that'll ease things a bit.

[DatsunBanana]

Aleks, how long was the hose for your oil drain. I need to buy a length of that and I'm thinking half a metre should be enough?