Z-Fever builds RB25DET powered 240Z, very clean build

[z-fever]

Here at Z-Fever we build some of the nicest Nissan vehicles around. We do a lot of unique swaps and this is just one of them. We normally do the RB25 swap into the 240SX but in this case we installed it into a 240Z which never came with fuel injection. Here is a picture diary of the build. The customer shipped us the car from Kentucky, we built it and shipped it back. This is a rather common practice for us.
I hope you like it.

We started with your basic stock 240Z:


Then we pulled the stock L24 engine from the engine bay and discarded it (if anyone needs a replacement engine for their Z you can call us, I will sell it to you):


Then we replaced the OEM RB25 intake manifold with a Greddy style intake. They look a lot nicer than stock and make for a nicer install because the hot side is now on the L-side of the car and the cold side is completely on the R-side of the car. Requires less piping and looks cleaner. However, the after market manifolds do reduce overall torque on stock turbo applications. The stock intake manifold actually performs better (be aware of that). BUt them sure look a lot nicer!


L-Side eng mount:


Our customer wanted to keep A/C (thanks God!) so we made custom a/c lines by welding the ends that came on the a/c compressor lines to the stock 240Z lines. Basically making hybrid a/c lines...


Then we had to make the intercooler fit the car. We did not want to cut any of the factory sheet metal soooo..... We decided to fabricate the ends of the intercooler where they would line up with the openings on either side of the radiator.....




In retrospect I would do the end tanks a bit nicer and smoother. BUT, these worked well and fitment was perfect. In the future we will make the end tanks differently. Don't beat us up here. We were given the intercooler by our customer because he was trying to save money and already had the intercooler himself!


Then we made the piping from teh turbo to the intercooler and the intercooler to teh throttle body...


Then we moved to the cooling system.... We used a 3" core aluminum radiator made by CX Racing for the 300ZXTT. We did have to move the outlet to the passenger side and make the mounting points to from the radiator to the front radiator support. We also mounted a set of Flex-A-Lite 440 dual electric fans for ubber efficient cooling capacity....


We used the stock RB25 transmission and this one was extremely clean...

Then we moved to the exhaust system... The stock RB25 turbo elbow cleared the steering shaft so we made the actual downpipe...



Then we made the complete 3" single side exhaust system ourselves. Noone make these for the Z chassis. It is 100% T-304 stainless steel and 100% mandrel bent with a tuned muffler... You should here this RB sing when revving up!!!!! Sweet music to your ears...



Now, the job is almost finished... The engine is installed, the intercooler is mounted, the piping is done, the exhaust is done, the cooling system is done, the a/c is finished, and we also made a custom driveshaft....
The wiring is done by us here in house also... We use the stock RB25DET wiring harness and ECU initially. Then the customer decided he wanted to be able to tune the car in the future with larger injectors and turbo so we switched out the RB25 harness and used the Z32 harness and wired it up using the Z32 MAF and ECU... They work 100% perfectly and are fully tuneable...
Here is how the whole product looked when finished:




Then our customer decided he wanted us to make all his gauges work however the OEM 240Z gauges will not work. The speedo is mechanical on the car and uses a speedo cable. The RB's trans uses a digital (voltage) signal to generate a speed sensor reading. They are not compatible. The same is true for the tachometer. Car's is analogue and engine is digital....
So, we purchased all white digital gauges from Autometer that fit the factory dash sizes and installed them and then wired them all up. Pay special attention to the gauge in the L-side a/c vent.... It is the boost gauge. I think this is pretty cool!




The finished gauges


Everything fit under the stock hood perfectly. You can't even tell the car has anything done to it from the outside until you start it and she takes off... The stock turbo with the Z32 MAF and OEM injectors only put down 260whp but when we upgrade the turbo and injectors those #'s will go way up. Even at these #'s the car is extremely fast. Especially considering that the stock L24 only put down 140hp and approx 90whp.... The 260whp is almost 3 times what was stock and the car is only 2000 Lbs...

I hope you like it..
Doug

[evildky]

thats a 72-73 240 so it weighs closer to 2400 lbs

if it had the later flat top su's and an e88 head it might only get 90 whp but a decent running e31 l24 with roundtops will get 120 whp stock and with tuning and smog delete 140 whp, they were under rated

with the stock diff and U joint half shafts, he won't but putting it to the ground and if he does those shafts are goners

[SBC 240Z]

wait, the 240z never came with Fuel Injection?

[DLeeTT]

wow, looks like it belongs in there. just wondering though, i'm a noob, why did you have to switch out the harness and maf to that of a Z32? Are the tuning capabilities limited with the rb harness?

[z-fever]

with the stock diff and U joint half shafts, he won't but putting it to the ground and if he does those shafts are goners

We have built 50+ S30's with V8 engines, at least 20 with RB25's, several with RB26's, a few with VG30DETT's, one with a 2JZ, and a few with SR20's... None of these destroyed the stock U-joint half shaft axles. Ironically, I have replaced 100's of those in my career in stock Z's due to failure. Heck, I am replacing one right now with the stock L28 engine.
With that being said, they are an area that should be addressed. We are building an AWD 280ZX using an RB26 right now. I installed an R33 GTR rear diff and custom CV Axles that we made.
Here is a link to that build:
rhd-280zx-w-awd-rb26-swap-and-more-z-fever-t543447.html

As for the Z32 ECU... we use that because we can't tune the RB ECU. We have used the Z32 ECU for years.. They are almost identical in function (but we have to re-pin about 8 wires and use the Z32 MAF)... A few Japanese tuners have created boards that work with the RB ECU... we have not though.

[DLeeTT]

So this means unless u go with a standalone, u cannot tune the RB ecu?

[evildky]

with the stock diff and U joint half shafts, he won't but putting it to the ground and if he does those shafts are goners

We have built 50+ S30's with V8 engines, at least 20 with RB25's, several with RB26's, a few with VG30DETT's, one with a 2JZ, and a few with SR20's... None of these destroyed the stock U-joint half shaft axles. Ironically, I have replaced 100's of those in my career in stock Z's due to failure. Heck, I am replacing one right now with the stock L28 engine.
With that being said, they are an area that should be addressed. We are building an AWD 280ZX using an RB26 right now. I installed an R33 GTR rear diff and custom CV Axles that we made.
Here is a link to that build:
rhd-280zx-w-awd-rb26-swap-and-more-z-fever-t543447.html

As for the Z32 ECU... we use that because we can't tune the RB ECU. We have used the Z32 ECU for years.. They are almost identical in function (but we have to re-pin about 8 wires and use the Z32 MAF)... A few Japanese tuners have created boards that work with the RB ECU... we have not though.

any of them not 1 wheel drive? guys are breaking these at 300 whp (in drag race situations), but they have lsd or welded diffs, they get traction of the line the car twists the drivers side angle increases and it twists the head off, road course, autocross, or retard (roll) racing won't allow enough traction to break anything

and he said "we can't tune" not that it isn't tunable, i know the rb ecu can be prommed, or romulated, guesing they use some software based tuning that doesn't support the rb ecu, the Z32 OBD2 swap is popular for people subject to emissions testing

[z-fever]

and he said "we can't tune" not that it isn't tunable, i know the rb ecu can be prommed, or romulated, guesing they use some software based tuning that doesn't support the rb ecu

[/quote]

There are some Japanese companies (like Mine's) that have created ROM boards that they can install onto the ECU that allows the data to bypass the OEM e-prom and read from the chips on the ROM board instead. We do this very thing for several applications also. We have our one board that we use for the late model (94+) Z32 and another one for the SR20DET ECU, the early Sentra's, the RB20's, the R32 GTR, the R34 GTR, and more. But the RB25 is a different animal. It was made by Bosch and has a totally different circuit board on it. We have never taken the time to create a ROM board for it and the JDM ECU's we get that have boards on them use encrypted e-proms and we cannot read them.
Our Z32 ECU solution is still much cheaper than Apex-i Power FC and it works perfectly.

[evildky]

the rb uses a bosch system? like the L jetronic found on the L28e and l28et? as well as the other jetronic systems used on toyota's vw's and countless other cars? it can be done it's just not worth it, datsun wisely dumped this system after 83, toyota used it through 93!

[gnosez]

Well, a couple of things:

1) the exterior looks like a 240 but the interior (steering wheel, horn, center console and maybe even the dash are either 260 or 280)
2) I agree the weight is likely closer to 2400 lbs and no even close to 2000
3) great looking exhaust! nice welds and bends (I'm partial to Sebring Tuning mufflers and would suggest you listen to one)
4) hope the owner has plans to upgrade both the tired suspension bushings and other related parts and then upgrade his brakes, booster and MC to handle the increased HP
5) those 1/2 shafts will be fine as long as he doesn't launch at every stop sign or light
6) I am surprised that it only puts down 260rwhp but perhaps you have set it a mid to low boost point to protect the engine bits. I say that because we run 245rwhp in our NA 240 race car (L28 non-stroked) and I have 255rwhp in my 3.2L NA street 240. BTW, the race car uses stock half shafts (280) but my street car has the Modern-Motorsport CV conversion setup.

Bottom line for me would be to compare build costs and expected engine life. Looks real nice and I hope you guys are in business for years to come......

[gnosez]

One last thing - those tail lights don't look to be 240 either.
Maybe this is a BSR sort of thing, where they took a 240 and put 280 taillights and a front valance and ran it as a 280.

[evildky]

the qurter panels are 240, it does appear to have front bumper shocks, I think they had those in 73? and yes that does look like a 260/280 tail lights, the spare tire well is 70-76, the console is also 260/280, the horn is 280z, so like many this car is a bit of a frankenz

your 245 whp stock stroke race car, what compression ratio? the fp guys are runing around your hp with 14:1 on race gas, stock internals, milled head

what kind of racing?

[gnosez]

We're running 13:1 on 110 race fuel. Just about everything but the block is from one of the early BSR cars. That includes the 2mm shaved and CC'd E31 head, the 8-qt oil pan, the diesel water pump, the pistons and connecting rods (new in a box from 1974) and the 44mm taper bored (50mm) triple Mikunis. Ours is only 20 over while the original engines were 40 over with copper wires set in grooves. Instead we use a Kameari head gasket that seems to be working ( we only have about 50 miles on the engine).

And we also have an original BSR valve cover. No, not the ones that say BSR on them and sell now for over $2,000. but the cover from the race actual engine. The race valve covers have a large AN fitting that connects to the catch can.

The L28 prepared by BSR were listed at 325hp @7500 rpm and 227 lbs of torque @ 6000 rpm but I have been told they ran some of the engines at nearly 16:1 with a life of about 6 hrs usage.3

[evildky]

maybe you should post a thread on your car with pic's?

[z-fever]

I agree... I would love to see your build!

[gnosez]

Will do so once I have finished preparing for a trial in Seattle next week.