Wondering if someone could shed some light on my pickle.... At the moment I am tossing up whether to build a motor or bolt up some bigger turbos/injectors/manifolds to my stock motor and see how long it will last. I did some digging today as I had asked Andrew at ASR at the end of last year to do a comp test for me. Pulled out of his report and it read Drivers 185, 185, 180 Passenger 175,175,170 (this must be #6?) Is this cylinder bad? Can I do anything to save it? Before someone calls BS on the numbers Andrew is ex-UAS and a very reputable mechanic, I dont think he would use a supercheap auto gauge. To me that looks like very healthy numbers which on the drivers side dont seem much off new. BTW the engine feels strong and it makes very good power for the mods it has + low KM @ 100K (Loss of licence had it in storage for 5 years) So what I am thinking now is that my motor appears to be healthy so it might be worth seeing how far I can go with this one and slowly build the beast engine on the side over the next 2-3 years or so.... however before I make any plans what do ppl think of cold compression tests and the numbers? Research has said you are supposed to do it warm however cold will be better to bring out any issues hiding.. Is this true? Also re Turbos, want as close to stockish spool up but large enough with a capability to hit 350RWKW on stock motor (only mentioning power to give you an idea of flow i want them to have) I will most likely run 300kw-ish MAX though after tune. The reason I say capability is that on a built motor with breather mods and porting etc these turbos I am looking for should move that figure to 400 RWKW which would be plenty. The plan is to buy the right turbos now and not buy and sell.... unless anyone has something good for sale I cant got past. 2560R/RS? JWT 530BB? 2530's? - Seem to be a little to much for a stock motor? Will they be laggy if i invest in them now with them being attached to a built motor in mind? GT525?? Seem to be a easy bolt up.... anyway they could make 350KW? Thanks, thoughts welcomed :br:
Hey man... those numbers look great! They would probably be a bit more even with a hot motor, so I wouldn't sweat the compression numbers. When my car still had the VG in it, I had the 2560r turbos on it and loved them. They spool quickly, and hit like a freight train when they spool up. I bought just the turbos, clocked them myself, and made brackets for the actuators. If you watch on Ebay, you can get those turbos very reasonably, and if you have even minor fabrication skills, you can put them togehter yourself, and save yourself a lot of money.
Here's some light on your 'pickle'! Those compression figures are OK for a NON TURBO VG30DE. The VG30DETT standard compression figures are 171 psi. With 128 psi being the minimum. A 14 psi difference between cylinders is the borderline on both engine variations. Your 'pickle' is now illuminated!
All a compression test does is give you condition of piston rings, bores and valve seats. It doesnt tell you what the bearings and rotating gear is like. If you want big KW, rebuild engine with forged internals, more aggressive camshafts and some GT28RS turbos and a decent clutch etc,etc.
It's unusual a professional wouldn't identify the cylinders number when testing. Could be: A faulty gauge. It's a Non Turbo engine. It wasn't really tested & the figures were made up. As suggested, retest the compression. At operating temperature with a fully charged battery & throttles open.
Andrew is a very respected guy as a zed mechanic and he is meticulous with his work from my experience. I doubt he would make it up given the 100k service was being done at the same time and it would take all of a few min extra. Hmmmm....
Andrew wouldn't have made the figures up, but different gauges can read low or high depending on calibration etc. Generally speaking with a compression test you're looking for variation rather than an absolute number. Generally.
No point doing the test if the results aren't accurate. When the compression is retested, the answer should be revealed.
The other possibility for high compression is someone has rebuilt and decked the head/block without getting a thicker head gasket, that normally sends timing out a bit too. I'm running the JWT 530BB turbos and making 230rwkw at 10psi with a few other mods on an NA engine, I would guess 350kw would be about the peak for these turbos and that would be pushing hard. E85 would naturally make it a bit easier to hit your target. As for spool they're pretty much the quickest you can get, don't have a good measure for it but I think they're hitting 10psi at about 2750rpm. More details on my setup here http://www.aus300zx.com/forum/showthread.php?t=329854 I should really update that some time.
Hmmm, I have owned the car since 2005 and imported it myself so I know the history of the car here. When i imported it was stock bedsides wheels and exhaust...its def not a N/A motor...all the running gear on the car is TT i.e brakes/diff etc. Cant see any point in someone dropping a na in + the dyno figures detail it making a bit over 260kw atm @ 15-16 psi (mainline dyno too which are accurate) A na would read lower with stock turbos... I am wondering if its carbon build up maybe as its not driven heaps in the past 12 months with a new run abut and doesnt do many long trips. I might stick some sea foam stuff that people talk about into it and see if changes much. What else guys should i get checked before i decide to bolt up some new turbos? 100k - done Cooler - done turbo back zorts - done twin intake - done plenum pull - done most hoses etc replaced + pwr radiator injector - Need bigger So from a servicing perspective I am sweet. How else can I make sure the motor is up to it 530BB's sound good. Anyone else got thoughts on these?
Short of pulling your engine apart to check bearings and clearances I don't there's much else to do, you can visually inspect the bores and pistons but that's about it. For injectors you Nismo 740cc, sard 850cc or go top feed, I think Rob is looking at getting some bolt-on BDE top feed kits in. Personally I wouldn't expect to make 400rwkw from the JWT530 without E85 so only choose them if you don't mind sacrificing power for response, they're fun on the street but you'll have flow issues at high power and will need high pressure wastegate actuators to hold boost.
going to look seriously into these 530's.... the seem to make boost everywhere from what I have found and come on strong. I have just been doing some research and it appears Nistune is now doing some stuff to make the ECU compatible with e85 which should shave heaps of a new ecu. See links below. So to set flex fuel e85 up I would need these items below, bigger injectors, e85 pump, new lines and a tune.... could get away with it for 2K ish if Toshi can tune for e85 for me on top of the current tune. Is this all I need? https://conceptzperformance.com/Cart/description.php?II=16325 https://conceptzperformance.com/Cart/description.php?II=16316
Depending on power you'll need the following for flex tune ECU Sensor Injectors Rail Fuel Pump Regulator
