VQ35DE in S13 in progress.....

[SpecDRacing]

Running a returnless fuel system is good, and bad. Good, less hoses, bad, requires more fuel pressure. The reason it requires higher fuel pressure is to compensate for volume loss under heavy demand. While the stock VQ35 in a RWD setup is 51 psi, I am running 41 psi on my return style setup and I still register rich on the dyno (and again, STILL not running IVT...I gotta get off my lazy xss and get that done!).

As for the Z32 fuel filter, I will crash this myth really quick. Go to Nissan, buy a fuel filter. Guess what you just bought, a 240sx fuel filter.....oh, wait, a 300zx fuel filter.....um, uh oh, wait again.....this fits the Xterra, Pathfinder, Supercharged Xterra..........Frontier???!!!! So, as you see, they are all the same. If your fuel filter is causing your fuel pressure to drop, then it is EXTREMELY, RIDICULOUSLY, INSANELY dirty, and you have way more problems then a bad filter. Id bet on sugar in the tank, or a pissed off ex-girlfriend, or both!

[SpecDRacing]

New IDEA!!!

Yeah, I know, haventy even really finished this one yet, but here goes.

So I have aquired yet another VQ35DE (RWD) block. Beside it, I have a VQ40DE engine. Hmmmm, wonder how much work it will be to mill the VQ35DE to accept the 10mm thicker crank from the VQ40? Then, how much work will it it be find the correct pistons and rods to stick in there? And after that is figured out, do I put the cylander heads I have on it...not just regular cylander heads, but the ones with both Intake and Exhaust valve timing control? Or, do I just buy VQ37HR cylander heads and use those (complete with cams, valves, etc. minus lift control motor is $599).

So Im thinking about it. If I do actually get to keep the heads I was just talking about (2006 M/T 350Z heads), I will probably build this engine. Im thinking 13:1, 4.0L with complete variable cam timing. That should be good for another 100 HP over what I have now. Just a thaught. I guess I have alot of pictures to take for you guys.

Oh, and before you build your VQ motor, take it to the machine shop and have them STRAIGHT bore the cylander walls to remove the taper. Trust me, while the taper helps seal the rings up top, it causes oil consumption, and that blows (no pun intended).

I am trying to get around to taking pictures of the car in a good setting. I also have to buy another hood. We are extending the stock hood about 3" and making the hump a shaker, like on the old hot rods. The front bumper has not recieved any work yet, so I am seriously looking rough right now. I even went as far as to write "BEATER?" on the hood.

Later all!

[SpecDRacing]

Also, sorry to everyong who has written to Nissandoctor. I have neglected to check that for some time now. Feel free to throw something at this post in anger, just remember, its your compu screen taking the hit! Again, im sory and I'll get to them as soon as possible.

[billya]

New IDEA!!!

Yeah, I know, haventy even really finished this one yet, but here goes.

So I have aquired yet another VQ35DE (RWD) block. Beside it, I have a VQ40DE engine. Hmmmm, wonder how much work it will be to mill the VQ35DE to accept the 10mm thicker crank from the VQ40? Then, how much work will it it be find the correct pistons and rods to stick in there? And after that is figured out, do I put the cylander heads I have on it...not just regular cylander heads, but the ones with both Intake and Exhaust valve timing control? Or, do I just buy VQ37HR cylander heads and use those (complete with cams, valves, etc. minus lift control motor is $599).

So Im thinking about it. If I do actually get to keep the heads I was just talking about (2006 M/T 350Z heads), I will probably build this engine. Im thinking 13:1, 4.0L with complete variable cam timing. That should be good for another 100 HP over what I have now. Just a thaught. I guess I have alot of pictures to take for you guys.

Oh, and before you build your VQ motor, take it to the machine shop and have them STRAIGHT bore the cylander walls to remove the taper. Trust me, while the taper helps seal the rings up top, it causes oil consumption, and that blows (no pun intended).

I am trying to get around to taking pictures of the car in a good setting. I also have to buy another hood. We are extending the stock hood about 3" and making the hump a shaker, like on the old hot rods. The front bumper has not recieved any work yet, so I am seriously looking rough right now. I even went as far as to write "BEATER?" on the hood.

Later all!

I thought we were putting that in my Z33? BTW nice fish last weekend

[irax]

sweet, I haven't installed the pump yet though. do you think I might even be fine with stock fuel pump?

[gregfarz78]

I emailed you at nissandoctor about buying some mounts off you, let me know if you even offer them and a price...no rush when you get a chance

[email protected]

[clrkh23a1]

you gonna post any pics of your modified engine cross member? We ended up making one that could use the factory G35 engine mounts. finsihed all the engine wiring harness. now we just have to remove the body harness and then tie into the 240sx body harness. We also installed the G35 fuse box system. Went with the 5AT transmission cause of the injuires i recived in Iraq I can no longer drive a manual. But we did beef up the trannt w/ a valvebody-torque converter upgrade(2300rpm stall rated @ 800hp) Then we modified the rear subframe to hold the R200 modified diff from the G35(Nismo 1.5 GT LSD/3.7 ring-pinon setup/Nismo Diff cover) Was looking for pointers on the interor harness setup, I know I have to use the NATS unit, but other than that I'm not really sure. ANy wise words of wisdom would be great. My goal is to make a completely street legal single turbo charged 240 (around 425-450whp) Thanks-SGT CLARK
Modified by clrkh23a1 at 1:45 PM 3/22/2008

[clrkh23a1]

Engine:Nismo R-tune camshaftsNismo HeadersNismo thermistatNismo ground wiresHKS DLI 2 ignition systemHKS spark plugs(1 heat level colder)Kinetix SSV intake manifoldKinetix high flow catsATI street series engine dampinerUR ss pulley kit(2-alt.-power steering pulleys)C&R performance radiator for SRAAM stage 1 return fuel system w/550 cc injectorsAAM re-flashed ecuBC tit. retainers/valve springsPort/polished head(knife edge exhaust ports-cast marks smoothed out)Trust oil cooler kitTrust oil filter relocation kitJoe Gibbs break in oilAPS oil panARP head studsARP main boltsJE 8-5.1 pistons with pro seals(95.5)Eagle rods w/ARP boltsZ32 fuel filterWalbro 255 high flow pumpYellow top altima battery4 gauge power wireexternal transmission coolerCosmetic head gaskets(96mm)

Nothing to crazy wanna be able to drive it on the street on a daily basis. This build will use the complete stock engine harness/ecu etc. Thanks for reading and have a nice day. SGT CLARK

[Soravia]

Sorry to hear about your injuries. Driving is a lot less fun without a manual stick. Maybe you can get a paddle shifter or Manumatic somewhere.

For the hood, why not use a NISMO 350Z style? It looks extremely good on the 350Z, almost like a completely different car. I'm sure the 240sx can take that hood after some chopping and welding.

Stock Z Hood



NISMO Z

[Soravia]

I'm just about to get another S13 coupe shell for a VQ swap. Work on it will start pretty soon. I'll be working on it 5 hours or more every week. I have set both time and budget limit on the project.

Here's is my current plan. Please tell me if something is off or if there is a better solution.

VQ30DE from Maxima or Altima- Chose this for 1) Price is cheap 2) Will fit under stock spec hood since the engine is shorter 3) ECU management is easier.

350Z / G35 6 Speed Manual or Frontier / Xterra 2WD 6 Speed Manual. Also considering PathFinder 5 Speed Manual.

Using Modified S13 Driveshaft to aftermarket Torsen LSD in S13 pumpkin.- Chose this to keep as much stock parts as possible since S13 driveshaft would be much cheaper than 350Z driveshaft, etc. Will be using an Aluminum shaft.

Increase the compression of the engine to 11:1 like Honda S2000 so that it can only run on either 93 gas or E85. Reprogram the stock Maxima ECU to use the new fuel.- I believe in optimizing the engine to make as much power as possible is the best way to increase fuel economy. (without paying for the VVT)

Here are a few questions I want to ask- Is the VQ30DE shorter than VQ35DE? By how much? I'm trying to make it fit under stock hood.

- Can I fit a FWD VQ30DE in the S13 Chassis by welding S13 engine mount and VQ30DE FWD engine mount together?

- Can I fit a PathFinder intake on the Maxima VQ30DE head? I find that PathFinder intake manifold design makes a lot more sense than G35/350Z design.

- I will be making a custom intake piping by using custom individual runners all the way to the throttle body. Placing the throttle body right after the air filter. I am under impression that having extra long runners would increase low-end torque.

- Can I use 2000 Maxima Flywheel with 350Z / G35 / Frontier / Xterra / PathFinder Transmission? I believe parts for Maxima are cheaper even if aftermarket.

- Is it very expensive to buy gears for transmission? I plan to rebuild the transmission so that the 6th (or the 5th on 5 Speed) will be extra-long and I can save gas on highway and cruise.

- What kind of stuff should I expect to interface 2000 model Maxima ECU to S13 cluster? I see that interfacing with S13 cluster to 350Z ECU having a lot of things not working. How different is it to connect to a Manual normal cluster from connecting to a Manual HUD cluster?

- Your engine had the bores polished. I read the Nissan had them micro-finished (whatever that is). Would it not defeat the original Nissan work?

- The new HR pistons you bought had the skirt surface made smaller for lower friction. Can I achieve the same by cuttin sides off older design skirts?

- The HR rod is claimed to do better rpm even though it is supposed to be longer. Can I put and HR rod into VQ30DE? Will it be too long? Will I need to change bearings and crank shaft?

Thank you.
Modified by Soravia at 7:42 PM 3/23/2008

[irax]

you can not weld the mounts together it doesnt work like that unfortunatlyI'm making fwd->rwd vq35de mounts i can make you a set you can test fit and let me know if it fits

you can buy individual gears but its going to be expensive

5speed is not worth it

I recommend against a TORSEN LSD, a fresh VLSD would be perfect for auto-x and drag, or a welded diff for drag and drift.

extra long intake runners do increase low end torque but does not help top end. it would be more advantageous for you to just modify a maxima intake.

as far as clusters go, you can wire it allot of stuff up, but it would be easier for you to just use a maxima cluster, or even an R32 skyline cluster

[Soravia]

Why not Torsen? My SE-R Spec V has it and newer Miata has it too. I'm not sure but RX-8 has it as well.The extra long runners I'm planning would have the same or larger combined diameter as the stock intake. Just that each of them will be individual and the throttle body will be moved up to make higher travel velocity.The car I'm planning to use has HUD and I'm trying to keep it if possible.

[irax]

it is not possible to use that HUD. I have never seen anyone use that HUD with a motor swap that was not an SR. There are aftermarket huds out there you know.

torsen lsd is good if you don't make allot of hp, or actually race aggressively I have a friend that drifts a miata and he said he broke a tlsd in auto-x and is a common out come.

if your going to make a completely custom setup and take the time to tune it right, then you should be fine. but nissan put LOTS of R&D into this motor and its components. There is a LOT of math behind intake and getting the most of of it. Harmonics, frequencies, velocity over volume. The best would be 6 throttle bodies right off the head with runners going to it IMO

from my understanding the difference between the VQ30 and the 35 is bore and stroke, think about it if the block hight was different and the head hight was different, how can you frakenstien the crap out of these? you can use a 35 intake on a 30, you can use exhaust manifolds. you can switch cams. you can use 30 timing on a 35 with minor modifications. I migh be wrong though

[nissanguy16]

IF you need a s13 shell, I have one for $800 has new tires, s14 seats, and an additional dash without cracks. trying to get some money up for a VQ swap in my S14 kouki

[Soravia]

The work on my S13VQ will start pretty soon, I'm going to put on all new chassis bushings on my current S13 before getting another one though.

I read on Wiki that VQ30DE and VQ35DE have same bore with shorter stroke on VQ30DE. So I assumed that overall height would be lower. If not I'll have to make a shallow oil pan and lower mounts.

[SpecDRacing]

CLRKH23A1:

If you use the G35 "fuse box" you will be using the IPDM (Intellegent Power Distribution Module). And that will cause more codes for you. You should pretty much install the entire harness from a G to your car. By having an IPDM, you will be completing the CAN system circuit. The IPDM and the ECM are "terminating points" for the CAN system. They both have 120 ohm resistors in them. By leaving one or the other out of the circuit, many DTC's will not be set, as they can not be CONFIRMED. Dont think you can just stick a 120 resistor in the CAN lines anywhere either, this will cause even more trouble. Since your running an Automatic, you will DEFINATELY need the ABS control unit (housed in the ABS unit). This will need to be hooked up and working properly, complete with wheel speed sensors and all. Since it is from an Infiniti, it will also have VDC, which again, will need to be hooked up. So, as you see, you should just use the entire G35 wiring harnesses. THe wheel sensors can be added to your diff in the rear (use a 350Z or non turbo 300ZX diff) and the front wheel sensor rings can be acquired from an S14 with ABS.

You may need to email me directly ([email protected]) for more help. Your project is big.

Also, dont go 8.5:1 for the pistons. That is old school and too low. Todays systems are able to make faster adjustements to fuel and timing. I'd use the pistons from a pathfinder or even regular maxima pistons (and I have a spare set, if you want them). They are either 9.5:1 (?) or 10:1 (maxima). That will reduce spool time, reduce turbo size and increase low end grunt while maintaining off boost power, gas mileage and lets not forget, easy start up! 8.5:1 is more for 800+ hp. The stock pistons and rods can easily make 450 hp on 8-10 pounds of boost.

[SpecDRacing]

Using a 3.0L will be easier wiring and will be able to retain your cable throttle. The down side is the limited aftermarket support.

No, VQ35 pistons will not fit. The bore is different. I believe a VQ30 is 93mm and the VO35 is 95mm. The engine itself is not shorter. The manifolds will not swap without fabrication. The motor mounts will need to be custom as will the trans mount.

Installing a long 6th/5th gear will give you better gas mileage, unfortunately there are none available that will benefit you. I'd use a 350Z diff. It comes open or LSD with either a 3.3 or 3.5 something ratio (depending on model it came from).

I would not attempt a manifold unless you have a flow bench.

TIPS FOR BUILDING YOUR OWN INTAKE MANIFOLD:

1) It should have a plenum no smaller than 33% of the total displacement of the engine.

2) Valve timing, depth and size all affect port sizing.

3) Port sizing affects port velocity in all rpm ranges.

4) Port velocity affects torque and HP directly.

5) Short runners need to be matched to the amount of CFM's flowing through the cylander head, along with swirl patterns of that head, size of cam, and INTENDED rpm peak numbers placement (both torque and HP).

6) Long runners need to be matched the same, and will increase low end grunt at the expense of high end HP and torque.

With the tunning of todays computers and the great flow characteristics of the VO, why would you want to use long runners? Remember, HP is directly related to torque and RPM. More torque, more RPM equals more HP.

Also, if you make runners too long, you loose the port velocity exchange from cylander to cylander. This causes fuel to puddle at idle, causes dramatic power loss and pretty much just sucks all around for fuel economy.

The Pathfinder intake you are mentioning is not simply a long runner intake. Underneath the plenum, near the throttle body, it connectes to the lower manifold. Inside the upper manifold, it has butterfly plates which open durring certain engine operations. Basically, once the engine reaches higher rpms, the plates open, redirected the air from the longer runners down the shorter ones. This moves the torque curve higher and increases HP, giving it the ability to pull like a V8 at low rpms, and cruise like a 4 banger at high rpm....and, even then, pull a load.

You can use a 2000 maxima flywheel on a VQ35, but I am not sure the dowel in that flywheel places the crank positioning sensor pickup in the correct location for the ECM to properly monitor ignition timing.

I wouldnt try cutting down the skirts on your pistons. The HR pistons you pictured, are what I have in my engine. They are designed that way, not simply cropped. A machine shop may be able to do this for you, but its pretty pricey.

Finally, THE ONLY THING FROM THE HR THAT CAN BE USED IN A VQ35DE is the pistons!!!!! The rods are longer to accomodate a taller deck height (20mm taller). The HR egnine is a 4.0L block (same as pathfinder, Xterra and Frontier) with different heads, stroke and pistons.

The crank cannot be used as it is 10mm thicker than the DE model. Thicker means cutting up the block to accept the iron inserts for the bearings, not worth it. I will battle this when I put the 4.0L crank in my VQ35DE block. The reason for the longer rods is to place the pistons farther from the crank. When this is done, this decreases wrist pin angle, which increases the amount of rpms it can produce.

Sticking HR rods in your VQ30 will push the pistons right though the valves and out the valve covers. It'll never turn over once before damage is done. You may be able to bolt VQ30 heads on a VQ35 block to achieve higher compression, but you will have to have the pistons clearanced for this. And again, Im not even sure that will work!!!

I'm glad you've thought of all this stuff, its alot to ask, but I wouldnt get that deep into it. You'll spend way more money then you want and after changing that much stuff, it will be difficult to achieve any kind of reasonable driveability.

Also, the VO35 makes peak torque below 2000 rpm and carries it (almost completely flat) through to redline!!! This is far beyond any domestic engine performance numbers EVER! At the other end of the scale, HP tops at near the top of the RPM scale, again great, because there is where it should be.

[Soravia]

Thanks for your knowledge.So I suppose I should leave the VQ30DE engine pretty much as is and just focus on choosing the right transmission.

I think I will go with the PathFinder manifold. It seems to have the low-end torque design that I want for towing my track S13 with the V6 S13. (Yes I'm going to have two S13)

As for getting higer compression out of the VQ30DE. What should I do on a small budget? Will the stock Maxima ECU take to reprogramming for higher octane fuel?

[irax]

what radiator from what car fits into the 240?

i was looking at the pathfinder from 2001 +or z32 300zx radiator

but I don't know if they will fit or not

[Soravia]

Will the stock S13 KA radiator work with correct piping? I'm asking because I can get a full metal one for $99 and they work great for a 2.4L engine. 3.0L is not very far.

[miami-z]

so to build my vq35 i should go with pistons higher than 8:5:1? what would you recommend? as far as the build of the block it is getting pistons and rods. It will also be boosted. want to build a 500+whp bulletproof engine. Another question i have is what do you recommend as far as engine management, standalone or piggy-back? I have to say that you should definately make a "how to" video on this build. You have done amazing work. i see some vq builds out there but i always come here to learn and for advice. Thanks again

[Soravia]

I've seen some shop put single turbo on 350Z with stock internals to reach 700 bHP. (about 630 wHP) The external engine parts were modded though.

you should be fine at 500wHP so long as ECU is tuned properly. I'd go with piggy back. Most aftermarket ECU are not going to make use of all the features.

[SpecDRacing]

Miami-z:

8.5:1 are just too low. Nissans have two different methods of distributing fuel to the cylanders, one, is durring crank up and certain high rpm applications, where the ECM fires all the injectors at the same time. The second is durring idle and normal driving, where each injector fires with its corresponding cylander. So, by changing to 8.5:1 pistons, you'll have a hard time starting in cold weather, not to mention spend alot of time getting the "off boost" driveability right.

I'd go with a piggy back. Nissan engineers have spent more money and time on getting our cars to run as smooth and reliable as possible, along with keeping consitency in mind. No tuner, I dont care who he is, can match what the factory ECM can do. I'm not saying that there arent really good tuners out there, but I will say that none of them have the means to create the maps inside a Nissan ECM. I know a few who propbably could, given the right equipment, but its just not available.

To mix those two paragraphs together. If any of you have seen the start up video of my high compression engine, its is not only a testament to what I built, but to Nissan engineers for the work they have done on these ECMs. I bet noone knew that the gas in my car at that time was over 12 months old, 87 octane!!!! This means that the Nissan ECM started a 12:1 engine, with partially burning fuel, no completed exhaust and the cylander walls were on a fresh hone. It sat down and idled perfect the first time!!! I think that is just stupid amazing!!!!! I cant say enough about the japaneese engineers!

Go for 9.5:1 or maybe just 10:1. You'll make the power easier without requiring as much turbo. The stock internals can handle it, but be safe and put some beefier rods in. Sounds like your planning on having a really nice ride man, cant wait to see it!

[Soravia]

Quote »Long rods place less thrust load on the cylinder walls, thus generate less parasitic drag and result in less frictional losses as engine revolutions rise. A "short rod" engine has the opposite characteristics. “The short rod exerts more force to the crank pin at any crank angle that counts i.e.--20° ATDC to 70° ATDCâ€?[/quote]Seems like reducing piston's skirt friction isn't the only thing making low friction in HR. The long rod seems to play a good role in it.Is that why you're planning to use a 4.0L block instead of a block from 350Z? To get higher RPM out of same displacement?

[SpecDRacing]

IRAX:

The stock 240SX radiator works fine. I installed a brand new Nissan unit to my car durring the swap, and haven't had any over temp problems with it, even at the drag strip. If your worried, get a fluidine or koyo racing unit. I plan to upgrade to one of those as well. The piping is easy with the stock KA style radiator. The top pipe is in the correct spot. The bottom just needs to be plumbed over to the thermostat. I made a small bracket on the drivers radiator brace (the tension rod connects to it) to hold up the hose on that side, heading up to the thermostat.

Pathfinder, G, Z, Maxima, Altima, etc will not fit the 240sx. Sorry, but I already tried those. Big waiste of time.

[SpecDRacing]

Thats basically a little more in depth then what I was speaking of. Rod ratio is the total angle produced when the crank travels from 90 deg BTDC to 90 deg ATDC. The less degrees this angle is, the less the tendency for a piston to twist, thus keeping the piston more straight up and down.

I am doing the opposite. I am using a shorter block with a longer crank. This produces more torque, but reduces top RPMs. If I wanted to stay with 3.5 liters, I'd just get a HR bottom end. Yes, my pistons will have more angles to deal with. Not, its not as big a deal as you'ld think. In all honesty, there shouldnt be much difference in drag between that and a 3.5. Remember, what we are talking about is what oil companies all "claim" their oil can help with.

[Soravia]

So how can I improve the PRM limit (reduce friction and drag) on the VQ30DE without making any frankenstein out of it? Any quality parts (nothing too pricey like $2,000 pistons) I should get? Anything I can machine out?

I'm just curious, why are all the piston side skirts flat continuous surfaces on the sides? Why are there no dimples or grooves or drilled holes? Wouldn't that reduce friction while maintaining the coverage? Or is there issues with oil pockets if that is done to a piston side?

I'm trying to see why a Honda can go to 7,800 rpm and make peak HP there while a Nissan engine usually tops out at 5,500 rpm or 6,500 rpm.
Modified by Soravia at 10:19 PM 3/26/2008

[irax]

i'm not worried i just wanted something that i wouldn't need extra piping

[Soravia]

This is a graph I found for a nearly stock VQ30DE engine with K manifold.

Torque and HP goes up very well. ^__^

[Ricksil80]

Very nice