Jump to content
SAU Community

Recommended Posts

Hi guys,

I am currently building a rb30det with 30e block and r32 25de head. ACL bearings, OEM conrods, OEM pistons etc and ACL rings and the normal works on the head. Motor will be ready next week and i was going to run my motor in with a factory 25det turbo, question_ has anyone tried this?. and what sort of power were they gaining?. Im being realistic about the fact that im not expecting much HP from it. BTW im new to this site and thanks in advance for your time.

Cheers Tex.

Link to comment
https://www.sau.com.au/forums/topic/435543-25det-oem-turbo-in-a-30det-dohc/
Share on other sites

Won't make much cause the turbo will be choking it, around 180-200rwkw. My mate has a RB20 turbo on his twin cam 30, makes max torque at 2000 rpm but has nothing after 4k

All I can say is why? :|

A R34 turbo would run him $300 and have more usability.

  • Like 1

Yea i thought running the new build in with a ser2 oem factory turbo with rev limiter set at 3500, all with factory ecu tune. Thats not bad for a 20 det oem turbo, so i will running with better numbers then ay. HX40 turbo is the next upgrade. Just good to know someone has tried it before i did

bottom line is they are old turbos and the kind of flow a 30 is going to give it I see a turbo failure in its very near future.

decide on your turbo setup and shell the $ for it and do it all at once. no point in scrimping at this stage. (but on that note, why go this far and also go for stock rods and pistons?).

otherwise, im sure hypergear can sort you with a suitable turbo for the application at a damned good price.

GL

Stock rods are same as stock 30et rods and forged pistons are harder on the rings.Stock oem bits are proven over n over again by RIPS NZ for doing well over 600hp and still running stock,like i said im only using it to run the motor in.

Stock rods are same as stock 30et rods and forged pistons are harder on the rings.Stock oem bits are proven over n over again by RIPS NZ for doing well over 600hp and still running stock,like i said im only using it to run the motor in.

fair enough. I hear you :)

just be careful with a stock turbo as there is the small chance that if it lets go (highly likely if u keep it on there very long or run it a boost) that when it lets go its will smash the compressor wheel and send it into the motor. Obviously requiring a rebuild...

Yes it will work, it'll make full boost by 2,000rpm LOL. It'll get you running so that's the main thing. No point thrashing it though, the turbo will be chocking. It will drive pretty much like a stocker RB25 but with a lot more off-idle/bottom end torque. Run 8psi max (or 5psi off the gate), once the engine is ready, put a GT3582R on it :P.

  • Like 1
Guest
This topic is now closed to further replies.


  • Similar Content

  • Latest Posts

    • Nah, OEM washer bottle and brake fluid reservoirs are fine I don't know what it is with the plastic that Mazda used, some plastics, like the washer bottle and brake fluid res are fine, and still look new after 20 years use, where as the coolant expansion tank, and PS reservoir, that I replaced with new OEM items when I first got the car, turned yellow and started getting brittle a few years later If the dirty yellow stained plastics didn't trigger me there wouldn't be an issue, but they did, much like the battery bracket....... Meh As for going back to work full time to support car stuff, nope, why, because I own a Mazda NC MX5, not a Nissan R series Skyline 🤣
    • I've never heard of CJ-motor, so can't advise you on them. I'd just go straight to GCG for a GCG highflow though. Seems no point to use a middleman. I'm somewhat surprised that the price on the CJ site is lower than the GCG retail price. Even though CJ would get a discount of some sort, you would hardly expect them to give up so much margin. Maybe the price is out of date? Having said that "I'd go to GCG"...when I did my highflow, I went to Hypergear. I did this https://hypergearturbos.com/product/rb25dethighflow/#tab-dyno-results with the R34 OP6 450HP profile. With the BB centre (extra $400) and intially with the standard boost actuator, but I eventually got him to send me the high pressure one when I got to the point of being able to actually use it. Ends up costing the same sort of money as the GCG highflow, but this is, of course, the turbo that I KNOW has a shorter length core and so moves the comp cover rearwards. The GCG apparently doesn't do that. My mechanic also swears by the GCG highflow, given that we have another turbo rebuilder who does something essentialy the same as theirs, using Garrett wheels. He says it stands up at really low revs and makes good power. I haven't pushed my HG highflow past ~240-250rwkW yet (should have a little more in it, but unclear how much) and it does have a fairly gentle boost ramp. OK, it's much better now that I have gotten my boost controller tuned up on it.  A lot of my earlier unhappiness was because I couldn't keep the wastegate flap as closed as it needed to be (including some mechanical issues). I'd still prefer it to boost up nearly as quickly as the stocker, and it certainly a bit slower than that. So maybe the GCG one is worth the first look (for you).
    • Ok thanks 🙂 I will higly consider this. Any "known" company for a good reviews and experience to send that off? Is that CJ-motor good one? Or go straight to GCG site? I need to use VPN to even find some of those "shops" let alone access them 🙂 
    • You can literally put in as much WMI as it takes to quench the combustion totally (and then back it off a little, obviously), and it will keep making more and more power. The power comes from the cooling effect of the water (and the meth) and the extra fuel (the meth, which also has massive octane). It is effectively exactly like running E85. One might be slightly better than the other, but they are damn close. But with either you can lean on the boost or the timing (or both) waaaay more than with just petrol and the results are similar. Here's the first thing I googled for an anecdotal bit of evidence. Can't access the attachment without being a gold member, but it is there for the getting if able to, or searched up elsewise perhaps. https://www.hpacademy.com/forum/general-tuning-discussion/show/wmi-vs-e85/
    • Dang, those BBS are so nice! 
×
×
  • Create New...