Chev R

Good Evening Gents thanks for the input. I will hopefully know soon had a call from a supplier. Will hold on and do the right thing?

Good Evening everyone hope you all well and keeping safe. I am busy with a rb30/25 build and would like to finalize my build in the next 2 months however I am sitting with a little problem hopefully you guys can advise. My questions is what is the max hp the stock Rb25det head bolts can handle? I have been trying to source Arp head studs same as Rb25det but Unfortunately none of the suppliers in Sount Africa have stock and are all waiting for containers to come in. Been about 4 months and i would like to start driving the car. I have googled and came across a discussion that says they sitting at around 600hp on stock Rb25det head bolts. Not sure if this can be confirmed and if anyone has done something like this. Build breakdown as follows: Rb30 block Stock 86.5mm pistons with Hastings rings Stock rods but shot peened and Arp rod bolts Rotating assembly balanced Oil galleries drilled Rb25det cosmetic head gasket Acl main and big end bearings Rb25det oil pump and flowed New water pump Rb25det damper pulley 1.5mm oil restrictors Stock crank Rb25det head ported and flowed intake and exhaust Port matched intake Rb26 valves, quarters , retainers, valve springs, Lifters, cams cut 270 So the head is solid lifters and solid cams Top mount branch pic attached built by Marius Fullboost South Africa 38mm waste gate Greddy blow off valves Stainless boost pipes HKS Fuel rail Lucas 1200cc injectors 2 x bosch 044 Turbonetics Hurricane 7868 aka Benita Spitronics Mercury Fuel Management That about where I am at the moment. Any input as usual is appreciated and thanking you in advance for all the help and guidance so far with this build? Thanks Brian Chev R

Hi KiwiRS4T don't have the stock anymore have the 76mm. So you reckon I can make some power with it? What would you say should be the limit before the intake needs changing again?‍♂️ Sorry about all the questions I am stuck with it now so trying to see what are the limits and if any good. Valuable input?

Hi KiwiRS4T appreciate your response will probably need to take my intake with to check for mating. Currently use a Hks fuel rail would that fit? My throttle body is a 76mm atm. Some guys say I should go 80-90mm. So gathering from your response it's a bi go. Will have to research other options. Thanks appreciate your input?

Good Day Guys Chev R here hope you all doing well and keeping safe. I would like to please ask again for your expert advice and assistance please. I have fitted my Rb30/25 into my car everything looking good however with the added deck height of the Rb30 sub I am have to make a few changes. What I am after is input on the Greddy Style cast intakes. I can get the intake similar to the plazmaman intake manifolds too but they are ridiculously expensive in South Africa. My current intake i used the stock Rb25 bottom half with runners and built a plenum on top. Unfortunately this now stops my bonnet from closing. My Turbo has the same issue but will be dropping the turbo flange lower to get the clearance. Please see pics attached of fitment. Also attached is the cast greddy style intake. Not sure if any have used it and can advise if they any good? Any opinions will be highly appreciated. Would have preferred to have a custom plenum built on the old runners but too expensive as well. Sorry for long write up. Any honest input will be appreciated. Thanks Chev R (Brian)

Hi GTSBoy intake not of all the info and really appreciate all the guidelines. Very detailed. Will have to decide where I would like to be. Just had a thought I can possibly also upgrade my turbo to a 62mm inducer and 84mm exducer on the compressor wheel to a billet 7 blade or 11 blade. Will have to machine my compressor housing to fit. And leave the turbine as is as it measures about 64mm inducer and 74mm exducer with Ar68 housing. Once again thanks for the responses helps to have a clearer path of where I want to go. Will also research some other turbo options on the Garrett range.?

Hi GTSBoy the idea is to start of with 500hp and gradually increase. Car will be used on the street. Sub assembly is freshly built but not with forged internals. If I may ask what do you mean by 84mm? Is this 84mm on the compressor side or exhaust side? The Turbonetics measures 78mm on the top of the wheel and about 90mm at the bottom . Exhaust measures 68mm on the top of the wheel and 78mm at the bottom of the wheel. Comes std with a Ar96 exhaust housing T4 So the intent is still for the car to be responsive and not to have too much lag. Maybe to start boosting at 3-3500rpm. Hope this helps Sorry if I did not understand your response too well. Murray thanks for your response I gather what you mean

Hello Everyone Chev R here from South Africa. I am in need of advice from some of the guys that have done this before. I have checked a few threads on turbos that guys suggested and has been been covered. My need currently is this I am building a Rb30/25 and have got my current turbo specs as follows: Ar 70 compressor housing Compressor wheel 58mm Exhaust housing Ar68 Exhaust wheel 64mm Now some of the guys I know in the drag seen here advise that the turbo will be perfect down low but will probably choke towards limiter maybe 6000rpm. What is your take on this please need some guidance? I will be limiting rev range to 7000. One of the guys I know offered me a turbonetics 7868. I will attach specs as per my research. What I am after is is my turbo going to run out of steam higher in the rev range. If someone has had a similar turbo set up? If so would the turbonetics be a good second option as this is being offered to me at a good price. Car will be used for street and once the covid pandemic passes at the race track from time to time. Apologies posting again because I may have posted In the wrong forum. Would the turbonetics be a good set up for street mostly occasionally quarter mile track? Basic breakdown of my build Rb25det head a little work done to it. Solid lifter ,solid cams, ported and flowed with Rb26 valves ,quarter's, retainers and lifters Solid cams solid lifters , cams cut 270 Rb30 sub 86.5mm pistons , hastings rings Oil restricted 1.5mm Rods short peened , and arp rod bolts Rb25det oil pump Rotating assembly balanced Appreciate all the help and assistance Brian ( Chev R)

Hello Everyone Chev R here from South Africa. I am in need from some of the guys that have done this before. I have checked a few threads on turbo that guys suggested and has been been covered. My need currently is this I am building a Rb30/25 and have got my current turbo specs as follows: Ar 70 compressor housing Compressor wheel 58mm Exhaust housing Ar68 Exhaust wheel 64mm Now some of the guys I know in the drag seen here advise that the turbo will be perfect down low but will probably choke towards limiter maybe 6000rpm. What is your take on this please need some guidance? I will be limiting rev range to 7000. One of the guys I know offered me a turbonetics 7868. I will attach specs as per my research. What I am after is is my turbo going to.run out of steam higher in the rev range. If someone has had a similar turbo set up? If so would the turbonetics be a good second option as this is being offered to me at a good price. Car will be used for street and once the covid pandemic passes as the race track from time to time. I would appreciate your honest inputs on this please? Thank you kindly Brian ( Chev R)

Thanks Gts boy appreciate it. Guess I will have to send it back than?

Good Morning Guys hope you all doing well. Have not posting in a while been busy getting my build together. Just a brief I took the rb30 dohc and used that as a build guideline. Build a Rb30/25 with a series 2 sub. Stock pistons 86.5mm as the sleeves were oval. Drilled oil return galleries 1.5mm restrictor Rods short peened with arp rod bolts Rb25det oil pump New water pump Used my Rb25det head. Ported and flowed with Rb26 valvels, quarters , retainers, solid lifters and original cams cut 270. Just refreshed everything. Currently using rb30 gearbox but was grinding a little bit. So I opted to get a new gearbox seeing that everything is now being put back together. I had a call from a guy that imports engine etc. He said he had a Rb25det fat boy box. So I obviously jumped at the opportunity to get the box based on reviews. Got the box at home now and just checked fitment etc and started seeing some differences. My starter does not fit seems to be smaller. So I am worried I would have to change flywheel, clutch etc The bolt pattern seems to line up with backing plate but not starter bolts So it seems I would need to change the starter. Upon some research on google this gearbox seems to be from a Nissan bakkie the zd30 diesels gearbox. Basically my gripe is should I try and use this gearbox I probably need to change flywheel, starter and pressure plate. I don't like the Idea because i had my complete rotating assembly balanced. And with the covid pandemic not all engineering shops are operating. What I am after and if I can get your input please guys is? Has anyone ever used this gearbox or attempted to and what were you findings? Looks similar to pictures I see of the fatboy box. Also found this code not sure if this is rb though FS5R30A. Confused as I am doubting my decision as the guy assured.me it is a Rb25det fatboy gearbox and do not want to go through all the hassles as I wanted something straight fit that can handle more power. My clutch seems to fit though. I am attaching some pictures for review. I would really appreciate your input guys as you have been doing this and have the experience. Thanking you in advance Chev R based in South Africa

Hey Plynx You can actually see substantial difference's. Will have to get someone experienced to do this for me. Shot peening have confirmed with Fulrace collecting them today from my engine builder to drop off will find out if they can do it there maybe. Thanks for all the hassle in showing me this I have one more question if I may and this is with regard to the sump/oil pan and oil pick up? Here goes: The series 2 sub assembly I bought did not have an oil pick up so I have been searching on whether I can just use my Rb 25 det oil pick up and sump/ oil pan. I have come across some reading where guys say the Rb25 det sump needs to be modified and some fins cut but no real detail explanation. Is there any one that may have more info on this mod and maybe pic's if available? And is it necessary for me to have sump baffles fitted as this will be mostly a road car and from time to time on the track? Thanks in advance everyone any responses will be appreciated

Hi Kiwi Sorry I am not so technically knowledgeable but I will have a chat to our Skyline Guru this side and try and have this done. I do currently have a catch can but pipes run from cam covers. Will have this done aswell. Rods will be taken In on Monday to have the shot peen done. I attached just some pic's of how the setup looked. Thanks for all the valuable info from everyone so far it is appreciated? VID-20170422-WA0003.mp4

Hi GtsBoy Not sure what you mean by large duration can you elaborate? Please excuse my ignorance I am not really a engine builder. Something I will need to look into I guess

Hey GeeDog No I won't be using the VCT my head is solid cams and solid lifters. Sorry also did not realize but makes sense. Your input is valued