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Apexi, gas ocatne, head for rb25?

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requiem240sx

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Discussion starter · #1 ·
ok so today i called up a place called turbolab. . . its a local shop and they do tunes, swaps, etc on jdm imports. the owner actually owns an rb26dett skyline. anyways so he told me a few things that i dont know are true, or if he just wants money?

1) he was telling me that if i dont re machine the head then it wont run good at all unless you have 100 octane. does anyone know if this is true? because he says i should get an AEM ecu and get a tune which would cost a couple thousand. does the stock ecu go off of a person using 100 octane?

2) he also said that i need to take apart the head or have him do it for like reseating the valves? not exactly sure what he said but it was something to do with reduing the valves or something in that area because when the engine sits for a while then the oil runs down and then it gets dry and cracks? he said it would be like 300 to fix. does anyone know what he was trying to say? or if this actually needs to be done on an engine that has been sitting for a while?

3) can a fairly stock . . . (upgraded intake plenum) run with the stock ecu in the states good? or will it always run a little bad because of a few minor upgrades?

4) last but not least he was charging roughly 1500 for a dino tune. is this good or bad? and he also said his mechanic worked for rb motoring in california and is a really good mechanic for rbs.


thank you guys all so much for any input. i would really not like to have to put another 6,000 into the car for something that didnt need to be done.
 
#2 ·
1) you should phone a few shops to get there feedback, not just one.

2) what are your goals with the engine? Is he saying this is all necessary for the engine to run, or for the engine to reach 400hp? We need more info. Cant answer your questions without knowing this.

3) In my experience, 1500 is aloottt for a dyno tune.
 
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Discussion starter · #3 ·
alright so im hoping to have like 400 maye 450 to the wheels when im done. but right now i just want it running so i can drive it.
i will call a few more shops, and check prices but this guy owns a syline and his mechanic is suppose to be really good with rb engines.

also what would be a more "regular" price for a dyno tune? i also want to maps, so that i have track street.
 
#4 ·
You shouldn't need anything done to your head for it to run, or even for 400hp. I was researching what the stock head is good up to, and I found its about 500hp from several websites. And with an intake, there shouldn't be any negative side effects. Running on the stock ecu will be fine. But if you have a series two, the stock ecu is untunable. You can get a 300zx ecu and make it run with that. Any decent tuner will know how to do it. And 1500 seems really really high. Shops around here charge 650 for an ecu tune and dyno.
 
#5 ·
1. This is optional. I've never heard anything about the car not running properly on anything but 100 octane if you don't redo the head. Perhaps you don't understand what he was saying? The head on an RB25 could definitely use a little tweaking for higher HP numbers to improve the flow.

2. If the valves need to be reseated then they need to be reseated, regardless of the hp goals. I'm not really clear on his explanation though. Perhaps this too has been lost in translation?

3. The bigger plenum shouldn't matter too much, but if you put a bigger throttle body on the plenum like most people do then you might have some small issues with sudden changes in throttle because that's a lot of air. Anytime you start upgrading the engine you really do need to seriously consider an aftermarket or tunable ECU of some type.

4. That really depends on what he's going to do. Most places give you an hourly rate and very clearly outline what they expect from you and what they will do for that rate. It's nice if they have a separate rate for mechanical work, in case your car needs adjusting during the dyno run, etc. ... Overall it seems a little high to me, but not unreasonable if he really knows what he is doing and fully tunes every aspect of your ECU. If he doesn't have a dyno dynamics then I would find a new shop, because that's an absurd amount of money to do a tuning on a dyno jet or similar.

5. Good luck with your power goals. People say it's easy to get those numbers, but speaking from experience most of the people on the internet are full of shit and if the hit those numbers they aren't showing the proof or they are running a ton of boost and race gas....
 
#6 ·
If i were you i would inspect your head yourself first and make the decision if your valves are in good shape. Just make sure you are labeling when you take them out.

I had a head sitting and it accumlated alot of rust in the bottom of the valve, but it was exposed. Im getting a valve job with new guides now obviously because they really needed refreshing.
 
#8 ·
I've heard the 100 octane thing before, from what I've seen it's because in Japan it's labeled at 100 octane fuel but when you convert it to american standards or something like that it is equal to our 93. These were made to run on 93 but most can run 91 with no issues (Me included), never reseated the valves in mine and it's running good, you will need to look into tuning for 400-450 hp but if you're running with an upgraded plenum and that's it you'll be fine. I'm running a GReddy intake along with a Q45 TB and never had any issues with the stock ECU. Once you start getting into injector and turbo upgrades is when you'll need to have it tuned. You can run a 300zx ecu and get it chipped but I'm just going to go with an aftermarket standalone to help with tuning ease. 1500 is definitely high for a dyno tune. Most shops I've heard are usually around the 500-1000 range.
 
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#9 ·
^^^Hit it on the head. The lowest octane you can get here is 93, that's regular at the pumps here, and you have the option to go to 100 for premium. As Racer said, cars here are designed to run at that octane. As for running lower than that, I have no personal experience with that motor, but apparently Racer has had no issues going with lower octane.
 
Discussion starter · #10 ·
hey thanks for all the imput guys, i talked to a guy that knows a lot about rb motors, he said that in japan they run 100 octane on all thier cars. (maybe for smog and stuff?) but either way i think ill just stay with the stock ecu for now. the valves may need to be resealed because the rubber on them can crack and dry out after not having oil to lubercate them. ill start it and see if smoke is coming out really bad i will let it run for a few minutes then replace everything again. also i got my wiring harness today and an rb specialist is coming to my house to look at my swap and give me some input on it. he said i should really look into upgrading my oil cooler, plus i should also look at the oil pump. i replaced. but he said some oil pumps are prone to cracking and some are not. so ill have him check it out tomorow and hopefully it will be ok if not i have to replace the oil pump. but then it should be good to go.
 
#11 ·
Did you not read the post above yours? Not everyone runs 100. Just because he's a RB "expert" doesn't mean he knows all there is to know about Japan. I can assure you not everyone here in Japan runs 100, oh wait, I now own a car with a RB and I don't run 100. ;)

Yes, I would run an aftermarket oil cooler, especially if you plan on running up the boost any.
 
Discussion starter · #12 ·
ok, im not saying im not going to run less. just saying i rather put in what is recomened but has anyone tryed out different octaves and had any noticable differences? also i was going to turn up the boost to about 10 pounds. so not much
 
#13 ·
100 is way overkill. Again, in Japan it's rated differently from what I've read. 100 there is about 93 here. Run 91 or 93 and you'll be fine. Even at 10 psi. Hell, Radianation is running almost 20 psi if not more and he's still on 93. I wouldn't worry about the valve seals and what kind of oil pump did you replace it with? Just OEM? If so, you're fine. No need to worry about it cracking. The only issue with the oil pump that I know of is the crank snout being too short. Most people don't mess with it but with really high revving motors people usually either weld more material onto the crank or buy a collar and have it pressed on by a shop. Either way, you'd be removing the crank to do that and it's unnecessary for your power goals. Upgrading the oil cooler is up to you. On 10 psi, you'll be fine with factory. I don't know the point when it is pretty much required but I know only going up to 10 you'll be ok.
 
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Discussion starter · #14 ·
hey thanks so much for all the imput, i think that sounds a lot more realistic. and for the oil pump i think you know what your talking about, i dont understand what all of that means? but that is what they where talking about.
 
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requiem240sx
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