Living with the RB26DETT S14....

[underground]

Hey All,

I just wanted to give an update of some of the great things and some of the pitfalls encountered with my RB26 S14...

First off, the car is amazing... We don't have a 1/4 track here in Arkansas, but we do have a 1000ft.. I went 10.8 and 99 MPH, 2.0 60ft.... This would equal about a 12.6-12.8 1/4.... That was on stock 8 PSI boost... I could have easily shaved a 1/2 second off that time, if I wouldn't have been spinning so bad. Video posted on my website.. http://www.undergroundmotorsports.com

I wanted to run it bone stock to get a baseline... Next week, I plan to have the AVC-R wired up and tuned... At 15 PSI, the car should be in the high 11's... That is amazing....

A few problems I wanted to make known... The oil pan sits right on the crossmember, with maybe 1/2 of spacing.. This in itself is not a problem... What is a problem is the aluminum power steering line that run inbetween the oil pan and crossmember... I had to cut that line in two places on the driver side of the car and run a piece of 3/8" power steering hose found at Autozone... I found out about this change after the second run at the drag strip resulted in a broken line...

Second, and this one is major, is overheating issues... I have spoken with alot of tuners over the past week both here in the US and in Australia., and everyone agrees the car is gonna require some modifications..

First off, I would only recommend a vented hood, as this will allow hot air to rise out of the motor...

Secondly, you are going to need to run a 3-row radiator, I would recommend Greddy...

Third, you need to use some sheet metal and make ducting between the intercooler and radiator, to prevent heatloss....

Fourth, at minimum run two 12" pullers.. Pushers alone are useless, and I actually plan to run one pusher in the front of my radiator with two pullers on the other side...

Fifth, you are going to need to run the Nismo Thermostat.... This water heats so fast.....

I am only going to be focusing on my overheating issues.... The car over the past week has consistently been rising in temperature.. It started at 180 degrees and held there for about a day... The second day it crepped to 190... A week later, the temperature is going to the 230-240 degree, DANGER point...

Just wanted to give you guys thinking about the swap an update, as well as to let you know, its gonna nickel and dime you to death if you let it...Lol


Modified by underground at 12:32 AM 10/7/2004

[Wulfgang]

Heating issues? Does the stock GT-R have a vented hood??? I agree that some of those mods will help cool your engine, but aren't you running an almost stock engine/turbo setup?

It seems like you are saying that if someone were to transplant a GT-R engine directly into a 240SX without any other mods, then the same engine that was running fine in the GT-R will now overheat in the 240SX. That does not make sense.

I will also say once again that a lower temp. thermostat cannot cure an overheating issue by itself. NISMO thermostats keep your engine cooler so that you can run more timing advance, but they do nothing to help an overheating problem.

What radiator are you currently running, and what IC are you using? If you've got a GT-R IC and rad, then you should have no problem unless you blocked the radiator with the IC (or are using crappy fans).

[PROJECTRB240SX]

ACTUALLY THAT IS VERY TRUE THAT A STOCK ENGINE IN ONE CAR CAN RUN HOTTER IN ANOTHER SHELL....

FACTORS WHY:ENGINE COMPARMENT SPACE (I.E. DISTANCE FROM RADIATOR, MECHNICAL FANS ARE MORE POWERFUL THAN A ELECTRIC ONE, ETC.)HEAT DISAPPATIONAIR FLOWRADIATOR SIZEHEAT ESCAPE

CRAMMING AN ENGINE INTO A 5 INCHE SMALLER SPACE WITH A SMALLER RADIATOR AND LESS HEAT DISSAPPATION IS GOING TO CAUSE THE MOTOR TO RUN HOTTER.

A VENTED HOOD WITH VENTS AT LEAST 11 INCHES FROM THE WINDSHIELD (TO PREVENT THE COWL EFFECT AND RAM MORE AIR INTO THE ENGINE BAY) WILL HELP DISSAPATE HEAT THROUGH A VACUUM EXTRACTION.

LARGER (NOT ALWAYS THICKER), HIGHER FLOWING RADIATOR AND FANS. THICK RADIATORS AREN'T ALWAYS BETTER FIN COUNT AND AIR FLOW ARE MAJOR FACTORS IN COOLING.

PROPER WATER FLOW IS ALSO KEY.

[PROJECTRB240SX]

ANOTHER GOOD THING TO LOOK AT IS A ENGINE COMPARTMENT BELLY PAN.... WITH VENTS WILL HELP BECAUSE THE AIR UNDER THE CAR WILL FLOW STRAIGHT PAST THE ENGINE BAY INSTEAD OF FLOWING UP INTO IT ALSO SUCKING THE HOT AIR OUT THROUGH THE VENTS.

[RbKouki]

I dont care if it does overheat its still BAD A$$..

[Wykid 240]

Hey All,

I just wanted to give an update of some of the great things and some of the pitfalls encountered with my RB26 S14...

First off, the car is amazing... We don't have a 1/4 track here in Arkansas, but we do have a 1000ft.. I went 10.8 and 99 MPH, 2.0 60ft.... This would equal about a 12.6-12.8 1/4.... That was on stock 8 PSI boost... I could have easily shaved a 1/2 second off that time, if I wouldn't have been spinning so bad. Video posted on my website.. http://www.undergroundmotorsports.com

I wanted to run it bone stock to get a baseline... Next week, I plan to have the AVC-R wired up and tuned... At 15 PSI, the car should be in the high 11's... That is amazing....

Hey man, this is Jermay, I live in Memphis, TN. We have a 1/4mile track and are about to open a shop here called Road Rage Autosports(tm). Hit me up, I would love to see the car. . . email- http://[email protected]

later

[underground]

I will be bringing it to memphis as soon as we work out the cooling issues...

I'm about an 1 1/2 from Memphis and have been to numerous Tuesday and Thursday Test-N-tunes are Memphis Motorsports Park to watch Sandman run (6.8 sec 1/4)...

Take care!

Chris

[DSMs_Suck]

good to hear that overall its running good... there are always some bugs to work out...

Honestly switch the thermostat first and see if that helps at all, I wouldnt be suprised if your stocker from japan is sticking shut.

Also great times!

[Nameless EJ6]

Sorry to hear about the overheating issues, hopefully that gets cleared up.

Have you thought about propping the hood in the back?

The car is amazing~~!!

[Wulfgang]

ACTUALLY THAT IS VERY TRUE THAT A STOCK ENGINE IN ONE CAR CAN RUN HOTTER IN ANOTHER SHELL....

FACTORS WHY:ENGINE COMPARMENT SPACE (I.E. DISTANCE FROM RADIATOR, MECHNICAL FANS ARE MORE POWERFUL THAN A ELECTRIC ONE, ETC.)HEAT DISAPPATIONAIR FLOWRADIATOR SIZEHEAT ESCAPE(snip snip)

That was my point, sort of. There are guys running RB20's that have overheating problems. Are you going to tell me that an engine making only 50 hp more than the KA is overheating because the engine bay is too small? That is not the problem. Overheating usually happens when people block the radiator with a huge FMIC or use inadequate fans or when something is mechanically wrong (such as a stuck thermostat).

Btw, I have an R32 clip in my garage, and the engine bay is only about 2" longer, 1" taller, and 0" wider than my S14 bay. There were no vents in the hood, and the plastic is pretty standard.

He should be able to run with a stock GT-R radiator and IC in the stock locations with two decent 12" pushers, with A/C. If not, then something is either broken or the radiator is blocked.

[Wykid 240]

I will be bringing it to memphis as soon as we work out the cooling issues...

I'm about an 1 1/2 from Memphis and have been to numerous Tuesday and Thursday Test-N-tunes are Memphis Motorsports Park to watch Sandman run (6.8 sec 1/4)...

Take care!

Chris

Kool man. E-mail me when you are coming over.Jeramy

[gawdzilla]

Maybe using the N1 water pump will help with cooling issues?

[FAST-DATSUN]

The RB26 runs hot in any body!!!! You need a good oil cooler and radiator to keep it cool. the KA/ca radiator are made for about 160/180 HP over that there are going to be heating problems. SKYLINE's run hot even in Japan, they add bigger radiator and LARGE oil coolers, (2 on most high HP cars) to control the heat. Ducting the air you get to the radiator is very important, if the radiator get no air "???" Venting the hood will help some but you need to do everthing to control the heat under the hood and get the radiator cooling...

[goofynick6]

I am running 15 psi, warm climate, one 14" pusher fan, stock cooling system and mine can sit parked and not overheat...different engine, but still.

Nick

[Yellow4g63]

I am running 15 psi, warm climate, one 14" pusher fan, stock cooling system and mine can sit parked and not overheat...different engine, but still.

Nick

I noticed my RB20 dosen't run nearly as hot as my friends RB25? he has a N1 water pump in his and I have the stocker.

[underground]

Hey all...

Well, I think the motor is fine mechanically. I checked the Nismo thermostat, and it opens according to specs...

According to my friends at Tilbrook Auto and Dyno, out of Adelaide, Australia... the RB26DETT should run around 180-185 degrees farenheit ...this will give some of you guys that are doing the swap an idea of where you are at...

Today, I added a 12" pusher fan to the front of my radiator, and I must say, this looks to be a must do for this swap in a S14 chassis....

I am planning on adding another 12" pusher, to make (2) pushers and (2) pullers on my radiator....

Just with the one pusher fan added, my temps dropped over 30 degrees...

With my two pullers, the temps were climbing up to 230 degrees...

But, with the addition of the single 12" pusher, my temps haven't gone over 205 degrees, even under boost... it's staying at 195-200 off boost..

I think with these cars, the problem is simply... FMIC is blocking air flow, and basically the radiator overheats...

I am going to add the second pusher, and I will post back on here how my temp handles...

[underground]

Ye

I noticed my RB20 dosen't run nearly as hot as my friends RB25? he has a N1 water pump in his and I have the stocker.

Yes, the RB25 and RB26 run hotter...

[74260zt]

man... sounds like I'm going to have some issues with My I/C also.

I was already planing on a twin puller, rated @ 5k cfm. Also, I think I need the hood vent/scoop that came on the 88 Z31 to help out.

That Underground 240 sure is sweet.....

[Wulfgang]

underground, can you post pics of your setup? I would like to know what radiator you are using, what fans you are using, and how your IC is mounted (is it the GT-R IC?).

Only a few people have been able to fit pullers with the RB's, and I am wondering now if the engine is so close to them that it is blocking airflow behind the fans. In this case, pushers may work better. I know pushers have an advantage when shrouded properly, but according to Perma-Cool, pushers are only about 30% less efficient. That's not so bad.

[underground]

http://www.undergroundmotorsports.com

You can find plenty of pics there...

I am using the Fluidyne KA Racing Radiator,

am using the Flexalite Low Profile for pullers..

http://www.flex-a-lite.com/aut....html

and Permacool 14" and 12 High Performance Pushers"http://www.permacool.com/Catalog/Cat_page16.html

I have the Hybrid Development 24x12x3 (GTR sizing) FMIC... That is amazing... My EGT never gots above 10....

[Wulfgang]

Nice pics! Your car setup (and clean engine bay) emphasizes how much the McKinney mounts move the engine back away from the radiator. Looks like you've got plenty of space.

But I bet that Fluidyne is your problem, or at least part of your problem. I am not a big fan of thick radiators. Wider and taller, yes, but thicker, no. Those pullers may not be able to suck enough air through such a thick radiator, so that you might be in a regime where running a thicker radiator actually gets you LESS cooling than a thinner radiator. No way to tell without switching radiators, tho.

Also, FWIW I have a suggestion on fans. Ditch the pullers and 14" pusher and just go with two 12" Permal-Cool high perf. fans as pushers. Yes, I know that PC says that the 14" pushes 2950 cfm, but if you look at the design, it is waay different than the 12" fans. It is totally unshrouded. Also, since the bulk of the air pushed by any fan comes off the blade tips, much of that 2950 cfm will be lost as it travels sidways across your radiator. The 12" fans will not only fit better on your radiator, but they have a circular shroud at the blade tips that should help push more of the air directly through the radiator instead of off to the side. The 14" may be suitable for very large radiators, such as truck rads, but imho it is too big for an S14.

[goofynick6]

Nice pics! Your car setup (and clean engine bay) emphasizes how much the McKinney mounts move the engine back away from the radiator. Looks like you've got plenty of space.

But I bet that Fluidyne is your problem, or at least part of your problem. I am not a big fan of thick radiators. Wider and taller, yes, but thicker, no. Those pullers may not be able to suck enough air through such a thick radiator, so that you might be in a regime where running a thicker radiator actually gets you LESS cooling than a thinner radiator. No way to tell without switching radiators, tho.

Also, FWIW I have a suggestion on fans. Ditch the pullers and 14" pusher and just go with two 12" Permal-Cool high perf. fans as pushers. Yes, I know that PC says that the 14" pushes 2950 cfm, but if you look at the design, it is waay different than the 12" fans. It is totally unshrouded. Also, since the bulk of the air pushed by any fan comes off the blade tips, much of that 2950 cfm will be lost as it travels sidways across your radiator. The 12" fans will not only fit better on your radiator, but they have a circular shroud at the blade tips that should help push more of the air directly through the radiator instead of off to the side. The 14" may be suitable for very large radiators, such as truck rads, but imho it is too big for an S14.

Agreed and agreed 110%

[DSMs_Suck]

Nice pics! Your car setup (and clean engine bay) emphasizes how much the McKinney mounts move the engine back away from the radiator. Looks like you've got plenty of space.

But I bet that Fluidyne is your problem, or at least part of your problem. I am not a big fan of thick radiators. Wider and taller, yes, but thicker, no. Those pullers may not be able to suck enough air through such a thick radiator, so that you might be in a regime where running a thicker radiator actually gets you LESS cooling than a thinner radiator. No way to tell without switching radiators, tho.

Also, FWIW I have a suggestion on fans. Ditch the pullers and 14" pusher and just go with two 12" Permal-Cool high perf. fans as pushers. Yes, I know that PC says that the 14" pushes 2950 cfm, but if you look at the design, it is waay different than the 12" fans. It is totally unshrouded. Also, since the bulk of the air pushed by any fan comes off the blade tips, much of that 2950 cfm will be lost as it travels sidways across your radiator. The 12" fans will not only fit better on your radiator, but they have a circular shroud at the blade tips that should help push more of the air directly through the radiator instead of off to the side. The 14" may be suitable for very large radiators, such as truck rads, but imho it is too big for an S14.

I third that! Side note: RB20 with cheap (but decent designed) ebay fans, 2 12" as pushers with ZERO overheating problems at a stand still or under full boost.

[Joe]

ill chime in and say yes, thicker radiators tend to cause problems with turbo 240's that have FMIC's and aftermarket electric fans. ive seen it happen to a few SR's and more RB related to Krayton's RB25 S14 with a koyo. he removed the koyo and put a stock S14 radiator back in (like i told him to run in the first place) and has never had a temprature problem.

its just too much blockage for the fans to move enough air to cool that big engine with a big FMIC AND a nice 3 row radiator.

[lyon23]

Nice pics! Your car setup (and clean engine bay) emphasizes how much the McKinney mounts move the engine back away from the radiator. Looks like you've got plenty of space.

But I bet that Fluidyne is your problem, or at least part of your problem. I am not a big fan of thick radiators. Wider and taller, yes, but thicker, no. Those pullers may not be able to suck enough air through such a thick radiator, so that you might be in a regime where running a thicker radiator actually gets you LESS cooling than a thinner radiator. No way to tell without switching radiators, tho.

Also, FWIW I have a suggestion on fans. Ditch the pullers and 14" pusher and just go with two 12" Permal-Cool high perf. fans as pushers. Yes, I know that PC says that the 14" pushes 2950 cfm, but if you look at the design, it is waay different than the 12" fans. It is totally unshrouded. Also, since the bulk of the air pushed by any fan comes off the blade tips, much of that 2950 cfm will be lost as it travels sidways across your radiator. The 12" fans will not only fit better on your radiator, but they have a circular shroud at the blade tips that should help push more of the air directly through the radiator instead of off to the side. The 14" may be suitable for very large radiators, such as truck rads, but imho it is too big for an S14.

I agree also.. I have 2 10" PC and they push 1250 each, I have one pulling and one pushing I have no overheating issues even with the ac on. stock radiator...

[Ralph]

Hey guys, I wanted to ask a question with these overheating issues. I havent followed it too much and was thinking about swapping a RB26DETT into a S14 as well(currently running a SR20DET Redtop). Not sure if it has any real effect but there is a guy locally that built a SR powered 240z pretty much all the way custom. The one thing that stood out on the deisgn was the "v" shaped intercooler on radiator design. Not sure whats its really called but I saw the same design in the most recent issue of SuperStreet on the cover car, the SR swapped Camilion painted Veilside 350z.http://www.superstreetonline.com/toc/

The design puts the intercooler almost in the engine bay and the radiator at an angle below it which I would assume would direct air to both at the same time without blocking one or another.

Could this design be a solution to the RB26 cooling issues?

[underground]

I would doubt it....

As far as I can tell, there is no room to do the intercooler there without moving the motor back about a foot...

I am leaning towards thinking it might be a water pump issue... It is moving water, but the flow rate seems very weak..

I have the stock pump that came on there, and I'm guessing the blades are probably worn down...

That is the next thing I'm going to target...

If that isn't it, its gotta be a headgasket...

[Wulfgang]

The v-mount was discussed on this forum a while back. I also doubt there would be enough room to even consider that option.

[foCk]

I have a RB20DET with an A31 radiator (basically same as S14) and 2 A/C fans off my car and the clip and it stays very constant at a standstill and WOT

[underground]

I'm glad you are having no problems or complications...

The RB26 is a very different beast trying to keep cool..

You are adding even more heat with the extra HP,etc..