Installing A Nm35 Vq25Det In A C34

[darrinspencer]

Just thinking out loud here.

The idea is to fit a VQ25DET into a C34

Why?

Something different

Prefer to run as manual RWD. Easier to do engine and gearbox driveline conversion

Target 250-300rwkw......can they make this much

I need to do some reading up on Vq25det mods etc.

I have 10 years Rb experience....no VQ25 knowledge

Main issues to work out

1. Pretty sure it will fit in between strut towers. Engine mounts to fab

2. ECU wiring issues....Do people have VQ25det wiring diagrams they can flick a copy to me?

Should I go stand alone ecu and be able to tune it than work with factory VQ ECU?

3. What manual RWD gear box and clutch etc.....All 350Z, V35 skyline stuff?

Any cheap gearbox options, but as strong?

4. Basic connection problems of water, intercooler, exhaust, intake etc.

[SABBAi]

Here is a VQ35HR into a 32 GTR. Going by the pics there is enough room to fit it between the towers, etc. I think the way he's done some stuff is a little naff, but it works.

http://zilvia.net/f/builds-builds-only/346234-retarded-vq35hr-r32-skyrine-build-20.html#post4842144

and first page is here.

http://zilvia.net/f/builds-builds-only/346234-retarded-vq35hr-r32-skyrine-build.html

[180fan]

If you want rwd manual, why would you go vq25 over a vq35, especially given the turbo / supercharging kits available for the vq35?

[darrinspencer]

Vq25det is already turbo. So compression is right, turbo manifolds etc

Can get a vq25det front cut for $1000

sell rb25det

vq35 is non turbo......add turbo or supercharger kit plus to buy engine equals $10K plus...

$ verse cents really

tring to keep to a cheap budget build

[bigkevracer]

VQ35 will be easier from an engine management standpoint, controlling throttle, cams, etc.

Anything can be done with enough time and/or money.

I'd be doing VQ35 with VQ25 heads, and I think the turbo manifolds then bolt up?

[PN-Mad]

main problem with a FI VQ35 is the strength of the connecting Rods. Fine for low boost, but VQ25 has more unopened potential.

[darrinspencer]

Agree

Target 250-300rwkw on the vq25det...... fit a bigger turbo and injectors and fmic exh....easy.

Ecu is main issue

Neo Rb25det.....Nistune ecu....cheap good workable solution

[scotty nm35]

VQ35 will be easier from an engine management standpoint, controlling throttle, cams, etc.

Anything can be done with enough time and/or money.

I'd be doing VQ35 with VQ25 heads, and I think the turbo manifolds then bolt up?

The VQ25det manifolds bolt up to the VQ35de heads.

Just drop it in with either a 350z/V35 6 speed box or a 300zxTT box and adapter plate. You would be best getting a standalone ecu, Link, Vipec or Haltech but there are cam actuation issues to work through.

[180fan]

Vq25det is already turbo. So compression is right, turbo manifolds etc

Can get a vq25det front cut for $1000

sell rb25det

vq35 is non turbo......add turbo or supercharger kit plus to buy engine equals $10K plus...

$ verse cents really

tring to keep to a cheap budget build

Yeah fair enough, remember though that an m35 front cut, at least in australia, wont have a manual gearbox. I'm guessing that a 350z gearbox would be the best one to use, no idea what sort of price they go for though

[darrinspencer]

The VQ25det manifolds bolt up to the VQ35de heads.

Just drop it in with either a 350z/V35 6 speed box or a 300zxTT box and adapter plate. You would be best getting a standalone ecu, Link, Vipec or Haltech but there are cam actuation issues to work through.

Who makes the gearbox adaptor plates?

off the shelf or custom made?

Cam actuation....do mine like VCT?

Most aftermarket ecu's have a trigger to turn on and off

I suppose its not on/off, but varible

I had a similar issue once with a motec M4 on a black 20V 4age

I might grab the VQ anyway....workout the issues later

Can always sell it again if I do not use it or if its too hard

[scotty nm35]

The adapter plates are made over in Perth somewhere, have a read of this thread...

http://www.skylinesaustralia.com/forums/topic/358412-z32-300zx-with-vq30-twin-turbo-conversion/

He will know where they came from...

As for the cams, they are constantly variable giving around 40kw more midrange in my car and making the turbo much more responsive. Well worth keeping the evct if you can, I know Trent (Status) got the Link G4 to work with a similar Vcam RB26 setup which proved it was possible, I guess you need to find a good tuner that doesn't mind experimenting.

[PN-Mad]

You'll need a RWD sump, not the AWD.

Go to Mercury motorsport and make them an offer on one they have sitting around.

[zei20l]

sounds like a good mod. is the engine bay wide enough to accommodate that motor? just remember youre still going to have C34 handling

[Raysboostin]

Heres a crazy idea that could just work. If u could find a crashed navara with a manual vq40 in it, you might have a cheap way to do it. If you stayed NA for now you could convert with all the oem ecu and stuff. Even NA would b pretty good in a stag with the mountain of torque from 4 litres. No need for head swaps, sump changes or adaptor plates. Then just build it with a turbo later.

[darrinspencer]

Engine fits between strut towers....done before in 32, 34's

Did not think about the AWD sump issue....thanks

So the RWD gearbox will not mate up with the AWD sump.....

The VQ25det alloy block should be lighter than the Rb25 cast iron block....right?

The stagea will be RWD, as lighter than AWD, plus the body will be a fair bit light too

So might end up closer weight to a skyline coupe.....should make handling a bit better.

Thanks Scott for info

[scotty nm35]

Thanks Scott for info

No worries Darrin, all this info is here, just spend the night doing a search.

[darrinspencer]

Well.....I bought a 80-90% complete damaged M35 2001 today....

I will strip it, sell off the parts I do not need and keep the motor....for something

Spoke with Mercury today

They are building a M35 Stagea with a Trust T78 and 6 spd 34 GTR box behind it

It all mounted in the car.....still AWD

Might go check it out tomorrow for a look

[Commsman]

Spoke with Mercury today

They are building a M35 Stagea with a Trust T78 and 6 spd 34 GTR box behind it

It all mounted in the car.....still AWD

Might go check it out tomorrow for a look

We've been discussing this build. Take some pics for us if you can.

Interesting time starting for you by the sounds of it

[pipster11]

pretty epic build!

[darrinspencer]

If I go the VQ25det with a 6spd V35 box I will have to sort the speedo out as the C34 runs off the gearbox and the M35/V35 runs off the rear wheels

How do you do this in a C34???

The V35 6 spd is the same price ($1000) as a good R33/R34 RWD box. But the R34/R34 box needs a very expensive adpator to make it to bolt upto the VQ, but the speedo would be sorted.

Fould some VQ35 to Rb gearbox adaptors on US ebay for $1150 plus postage. Have not found a aussie one yet to compare price

Maybe cut and weld the bell housing like Mercury did on the R34 GTR box in the M35 would be cheaper....

Why can't I keep the VQ25det AWD sump? Do I have to change it to a RWD sump?

In 2 weeks I will have both the C34 and M35 cars to compare and probably answer some of my own questions.

Edited November 26, 2012 by darrinspencer