RB30DET 240Z Circuit Car

[Zedman240®]

Found a pic of Steve Newings 2 ltr Stanza sports sedan with the heli rear wing...

[Scando]

That's a serious wing!

 

Simon, the big wing will definately work. My 240 had a RX7 Group C bird bath when first built for 2B Marque Sports and it could be driven flat through turn 1 at eastern Creek, the duck tail won't let you go anywhere near that quick.

 

I know Dat2kman, Jason will have some moulds soon, and I have a spoiler. They do need to be modified to sit best on the car, and need to be done as a three piece to work properly.

 

You should get yourself to brisvegas so we can get the aero you need working

 

I'm heading to QLD for a holiday in a week.  The Z is a bit big to fit in my suitcase though 

[Scando]

Started playing with the new turbo yesterday.  Looks like it's going to fit with a few minor modifications but it's very very close to the engine mount.

 

It's a GT3540R with a a very small exhaust housing at 0.63 and has a 0.70 compressor.  The car it came off was making 580hp which is a hell of a lot more than I'll be making so I know it will flow plenty.  Just hope it's not laggy.

[sco_aus]

Thats a big turbo for a sohc engine, but with technology nowadays, it will probably still work pretty well.

[Scando]

Yeah a 3540 is a bit bigger then I would have went for if I bought a new one but I got it at the right price so it's worth a try.  It was on an SR20 before and it made boost from 3,000rpm so hopefully it'll be ok.  The small exhaust housing should definately make it come on quicker than a normal 3540.  I'm making a new dump for this turbo instead of modifying the old one so that I can easily change back if necessary.

 

Here's the video of the final race from last weekend.  The sound is a bit poor so I'll have to try some different things with the camera.

[bluerat]

I bet Kelv save's that under 'Favorites'

 

Man they are wide angle, It would look great on the headlight..... nah, might stuff up the aero, lol. Although I'd like to stick mine on the back drivers side window, I've seen a few done like that and It's a ripper. Next time.

 

I better get a youtube lesson so I can put my version up!!

[Scando]

Kelvin's beast sure disappears into the distance down the straights hey.  Man, that thing has some go!

 

I was thinking since the cameras are such wide angle I might try sticking it on the passenger side window on an angle so that the right side is facing me and the left side is facing the track and see what that turns out like.

 

[Scando]

Had the car on the dyno yesterday with the new turbo and cam.  Since the rear housing is so small on the new turbo the wastegate isn't big enough now.  I wanted 18psi but with the wastegate wide open it's making 21psi.  It should be fine for now but I'll be looking to get a bigger wastegate to get it back down to 18.

 

It made 266kw@wheels which is a 46kw gain and the power comes in a bit earlier than the old setup so I'm very happy.  Once we get the boost back down to 18 it should still make around 250 which is what I was aiming for so it's a good result.

 

I think I'll be content with that for now.  If I decide it still needs more I'll build a RB25/30 for it if I can afford it!

[zzzzed]

i like your work mate. I hope you dont mind, your car is inspiring my build   

[waxhead]

46kw is a great gain

As well as coming in sooner well done

What cam have you gone from to

 

[Scando]

I was running a factory turbo "B" grind cam.  The one I have now was done by powerplay (previously datrally).  They didn't send a sheet with the specs, I just told them what I use it for and that I wanted it to work well from 3,000-6,500rpm.  Max power is still at 5,000rpm    I'll post the dyno sheet up sometime when I get a chance.

[sco_aus]

Dude that's fuckin impressive from the L28, good shit man.

[Scando]

Here's the dyno graph.  Ignore the torque figure, as much as I wish it were true 

11468_d612ca29e5c892e45be46dcabca1029a67247fec.pdf

[sco_aus]

quite smooth and responsive too, nice one

[RB30X]

Do you have a graph of the torque curve?

 

Yeah you definently need that bigger wastegate.

[Vindicare]

Hey Scando,

 

Can I ask what ignition systems your running? Still stock?

 

Aaron

[Scando]

Do you have a graph of the torque curve?

 

Yeah you definently need that bigger wastegate.

 

Don't have a graph of the torque curve sorry.  I remember with the old setup it was making over 400NM at 3,000rpm and building more higher in the revs but I'm not sure what the max was.  Didn't see a torque figure while it was on the dyno with the new setup.

 

Yeah, definately needs a bigger wastegate.  Will find out this weekend if it overboosts up hills or stays at the 21psi it made on the dyno.  If it stays at 21 I'll live with it.  We tried a couple of runs in 5th on the dyno and it still stayed at 21 so hopefully it'll be ok.

 

Hey Scando,

 

Can I ask what ignition systems your running? Still stock?

 

Aaron

 

-Basic Bosch oil filled coil.

-Haltech single channel igniter

-RB30 Distributor

-NGK Iridium plugs (these are worth every cent in my books)

-Haltech Sport 2000 controling it all.

[garvice]

What gap did you have to go to with the ngk plug?

I originally left the iridium plugs at there standard gap whilst tuning, but a few months down the track I got a bit of hesitation. Ended up gapping them down to about 22thou.

 

Actually that is probably irrelevant as I am running different coils.

[Scando]

At the moment we're just running them with the standard gap but with the little bit of extra boost it's just starting to hesitate where it's making maximum power.  Have bought another set cause that set has been in the car for ages and will set them with a smaller gap.

[Scando]

Had my first race meeting with the new setup on the weekend.  The car was incredible to drive.  It comes on so much harder and earlier than it used to and the torque is unbelievable.  The downside of this is the gearbox wasn't up to the job and I destroyed 3rd gear in qualifying.  My previous best time was a 59.5 and I did a 59.1 on the 2nd lap of qualifying but then I busted the box.  Considering I completely stuffed the first corner on that lap and I was using the Bridgestones which are generally half a second slower than the Dunlops, I'd say the car would be good for low to mid 58's which is a huge gain.

 

Since it was a 2 day meet we took the car back and fitted the spare box (standard 280ZX), went back to the 15psi spring in the wastegate and disconnected the Blow off valve to get the boost back down.  Unfortunately the spare box was jumping out of 3rd and I could feel a tail shaft uni on the way out so I packed it away for the day.  I still have a lead in the series but I'll just have to wait and see if it's enough to hold on to at the last round.

 

In the meantime there's more important things to worry about.  We're on the boat to Phillip Island in 8 days!  I'm going for a VL/R31 box with the L-series bell housing.  It has bigger gears than the FJ Turbo box I busted so hopefully it will be up to the job.  The other problem is that with the boost backed of the engine temp was fine but it spat water out of the overflow like it was overheating.  I think this may be because we have fed the water return from the turbo straight into the top tank.  I have ordered a little electric pump to put in the line which will hopefully circulate the water quicker and stop it boiling.

 

I'll still run it with the BOV disconnected for PI for reliabilitys sake which is a bit of a shame cause it would have been great to run it with the full power but there's a few things to sort out before I can do that.

 

At the moment we're just running them with the standard gap but with the little bit of extra boost it's just starting to hesitate where it's making maximum power.  Have bought another set cause that set has been in the car for ages and will set them with a smaller gap.

 

Set this at 25 thou and it got rid of the hesitation

[garvice]

Sounds like you need to upgrade to a Z32 box mate.

Still haven't put mine is as I am still enjoying driving my car and don't want it off the road just yet.

[sco_aus]

RB25 box

Awesome times there mate.  I did a 1.06 (I think) in a TT supra, so I can only imagine how much quicker it feels in yours.

[Scando]

RB25 box

Awesome times there mate.  I did a 1.06 (I think) in a TT supra, so I can only imagine how much quicker it feels in yours.

 

Sorry, didn't say this meeting was at Baskerville.  My best time at Symmons so far is a 1:00.1.  Hopefully should go under the minute there too with the new setup.

1:06 in a TT Supra road car is actually bloody quick if it was on street tyres!

 

I'm trying to avoid the weight of a RB25/Z32 box.  The VL box is a nice easy conversion too.  Slip on the L-Series bell housing with a couple of minor modifications.  Bolted it in tonight and the tail shaft fits perfect plus the gear lever is in the right spot.  Just need to fabricate a new mount.  And they're a bit closer ratio than the Nissan turbo boxes.

[RB30X]

went back to the 15psi spring in the wastegate and disconnected the Blow off valve to get the boost back down. 

I'll still run it with the BOV disconnected for PI for reliabilitys sake which is a bit of a shame cause it would have been great to run it with the full power but there's a few things to sort out before I can do that.

 

I don't understand how your BOV has an influence on how much boost you run?? It's job is to release pressure from your inlet track when you back off or on gear changes so you don't bend a throttle blade or allow the pressure to go back through the compressor. You corrected your wastegate spring to 15psi, do you then run higher using a boost tap?? I'm lost on this one.

 

VL boxes are ok but if you can sacrifice a small increase in weight the VL turbo box is much stronger. If you have close to 200 killer wasps or more and plan on boosting in 4th and 5th than forget about the na VL manual. The next upgrade from that would be the RB25 box as mentioned earlier.

 

When you say you redirected water into the top tank, do you mean the overflow tank, the one that overflowed without the engine getting hot? Wouldn't that mean the discharge hose was higher than the turbo itself, normally they work with gravity. Perhaps the water is flowing slower through the turbo now that the discharge point is higher and absorbing more heat that before. How was it hooked up before this.

 

By the way, I so want to see photos and in car vids from PI. That track is so fast. I love watching moto GP there.

[Scando]

I don't understand how your BOV has an influence on how much boost you run?? It's job is to release pressure from your inlet track when you back off or on gear changes so you don't bend a throttle blade or allow the pressure to go back through the compressor. You corrected your wastegate spring to 15psi, do you then run higher using a boost tap?? I'm lost on this one.

The wastegate is too small for this setup so it's been overboosting to 21psi with the wastegate wide open.  This should be 15 or 18psi depending which spring I run in the wastegate.  If you disconnect the line from the BOV to the manifold the BOV opens as soon as it starts creating boost and bleeds off enough so that the wastegate can contol it to whatever spring I have in it.  The boost doesn't build quite as sharp this way either which will be easier on the gearbox.  This is not ideal but will do until I get a bigger wastegate.

 

VL boxes are ok but if you can sacrifice a small increase in weight the VL turbo box is much stronger. If you have close to 200 killer wasps or more and plan on boosting in 4th and 5th than forget about the na VL manual. The next upgrade from that would be the RB25 box as mentioned earlier.

I've done some research and the gears in the VL box are the same strength as the R32 gts-t box.  Only difference is ratios (closer in the VL box) and the 32 box has better synchros.  There's some very quick 32's in my class (250rwkw+) and when I did the ring around on monday searching for a box they all said the same thing "I don't bother carrying a spare cause I've never busted one".  The gears are much bigger than the FJ Turbo box I busted and that was fine with 220rwkw so I'll give it a go and see what happens.  The other thing to remember is a Z is a couple of hundred kg's lighter than R32's, VL's, etc so it's not going to put as much load on the box with the same power/torque.  I know the RB25 box is much stronger but by the time you pay $1500 for a box and then buy the fitting kit to fit it to an L28 it turns into an expensive exercise!

 

When you say you redirected water into the top tank, do you mean the overflow tank, the one that overflowed without the engine getting hot? Wouldn't that mean the discharge hose was higher than the turbo itself, normally they work with gravity. Perhaps the water is flowing slower through the turbo now that the discharge point is higher and absorbing more heat that before. How was it hooked up before this.

 

The old turbo wasn't water cooled so it didn't have the water feeds.  Good point about the discharge point being higher than the turbo but there's not many options other than to go higher than the turbo.  The return line goes straight to the top tank of the radiator.  I think this is sending boiling water into the top tank and the heat is opening the pressure release on the radiator cap and therefore sending water into the overflow.  The other option was to go back into a fitting in the thermostat housing but I was worried this would effect the water temp sensor for the computer which also goes into the same spot and send the computer dodgey readings.  It still does circulate the way i have it setup cause the feed line is from the block where the water is under pressure from the water pump but it's obviously not circulating quick enough.  Anyway, hopefully this pump I've bought will circulate the water a lot quicker and stop it boiling.

 

By the way, I so want to see photos and in car vids from PI. That track is so fast. I love watching moto GP there.

I'm all over it    I tried something different with the camera on the weekend but have been too busy to have a look at the footage and see how it turned out!