how high are you trying to go reliably? 8000...8500... or 9-9500..? i have been drifting with my rb for 5+ yrs now and have melted the no1 ringland on stock motor with 25k.. ( du to bad tune but is a very cery known weak point on the rb25 internals... mines been revving to 6900 for yrs and im sick of it! what i know is as the heads concerned you can get a safe 8000 with springs and retainers and stock block with safe boost and tune..since i want to go higher the best bet on a rb25 non neo head is to do the solid lifter conversion from tomei... u can get all the parts right now for $1800-$2200 this will let you go to 9-9.5 k!! but at this point you need a fully built and balanced motor... i have the block built now so i will be going solid... NEVER FORGET ABOUT the CAMS! lol

take what you must.... just get the head refurb with springs and retainers. 8000k and enjoy!

 

i would be shooting for 8000-8500k RPM reliably @ around 350-450whp. it will be used for autox/road racing. eventually i'll build the block when its time to shoot for big power.

but thanks for the info, i'll look into the tomei kit!

 

you dont need more revs, just get a better sized turbo. i bet your life it will be cheaper, and just as, if not more, effective

 

bigger turbo = more lag.

i dont like lag.

more revs = larger power band + amazing sound

 

did i say bigger turbo? = NO

properly sized means you have maximum efficiency in the RPM you use the most. why do you want so many RPMS for autox? it takes time for your motor to get that high. and turbos dont just work great for a long time, they are good for a certain rpm range and then your done. you cant get boost at 3k, and have it last to 8k.

P.S. your gonna hae a great time with lag if your peak boosting at 7k

like i said, size your turbo properly so you hae a lot of power around, say, 5k. that gives you room to play around elsewhere, and you can do a lot of fast driving at 5k. in autocross, your certainly not gonna be doing over 100. so, lose your attitude if you want advice

 

oh yes i know that, i thought you said bigger. im not sure where you got off any attitude...but anyway
i plan to run a sequential TT setup as well, so with that it should keep power throughout the powerband from 3k-8k with the right tune, correct?

i am aware that autox is mainly mid-high range low speed high torque, and with a large range, i could stay in say 2nd or 3rd gear for most of the course, keeping the power and torque constant. an then for the track days, the extra room for ooomph would be nice on the straights and highspeed banked turns, and yet again i could "cruise" around certain turns in 1 gear as apposed to constantly shifting to maintain a good power curve.

but yes you are correct, its all about the turbo size and efficiency in the setup you plan to run, i know this and i am currently doing research and the math necessary to determine what size that will be.

 

...damn double post

 

lol. have you ever even seen a manifold vacuum diagram for a sequential turbo set-up?

 

enlighten me?

 

You MUST get into the block if you want to rev that much higher. You're going to need to get a crank collar, add at least one oil restricter and run an extra head oil drain. Getting an RB26 head is the cheapest route for head upgrade. You don't need to upgrade the HG for your power levels.

 

i've thought about the RB26 head, i just figured for the price that i could get one for i'd be better off just to build my current one. this setup would most likely be a way down the line, i just wanted some information so i know as what to look out for and save for. If the block is a must, well then i'll rip into it and get that done as well.

The biggest problem with more revs is more harmonics and that's what destroys engines. These high Freq harmonics play a big role above 4000rpm. These vibrations damage your main and rod bearings, if transfered to your head these vibrations will cause your valves to bounce off their seats, ultimately bleeding off cylinder pressure and power. Unless these harmonics are controled or dampened the extra RPMs won't mean a thing. An easy route would be to install an ATI Super dampner and Titanium valve retainers. But the money spent there could go to your RB getting rebuilt and professionally balanced. Hope I was of some assistance.

i never thought about the raise in harmonics, thanks for pointing that out. sounds like my best bet would be to build the block. well alright, sounds like i've got more research to do

Doulbe post or P.S. My Rb26dett is completely stock with the exception of suction filters and 3 1/2 inch cat back. The engine is well capable of 8 grand and when I autox I rarely see that. I'm even running stock .7 bar. Think about what you ultimately want from the car and what and where could you make the most improvements. Will an extra 500 RPMs help? or learning proper heal toe shifting? You Tube has split screen videoes that show you what the driver is doing with his feet while entering and exiting corners. Just food for thought.

yeah i watch the videos here and there, its good stuff to know how to do or at least to begin to learn how to do early on. thanks for heads up though.

about what is your average RPM limit when your autoxing?

i'd like it to be quick revving, highly responsive with the boost lag to a minimum. i figured with a better flowing head, and lightened rotating mass that this could be achieved without necessarily tearing into the block quite yet, but now on further investigation it seems its almost mandatory to do so. i'll keep researching other builds and see what i can cook up.

 

The biggest problem with more revs is more harmonics and that's what destroys engines. These high Freq harmonics play a big role above 4000rpm. These vibrations damage your main and rod bearings, if transfered to your head these vibrations will cause your valves to bounce off their seats, ultimately bleeding off cylinder pressure and power. Unless these harmonics are controled or dampened the extra RPMs won't mean a thing. An easy route would be to install an ATI Super dampner and Titanium valve retainers. But the money spent there could go to your RB getting rebuilt and professionally balanced. Hope I was of some assistance.

 

Doulbe post or P.S. My Rb26dett is completely stock with the exception of suction filters and 3 1/2 inch cat back. The engine is well capable of 8 grand and when I autox I rarely see that. I'm even running stock .7 bar. Think about what you ultimately want from the car and what and where could you make the most improvements. Will an extra 500 RPMs help? or learning proper heal toe shifting? You Tube has split screen videoes that show you what the driver is doing with his feet while entering and exiting corners. Just food for thought.

 

Talk to these guys, lol.
YouTube - S14RB25DET DYNO

It might be fake but w.e

 

yeah.. thats money. you see the computers, that means money. and only 347 at 13k.. come on. id rather hae 500 at 8k

 

Word. And to add to that, how long do you think a 13,000rpm engine will last?

 

as long as my cock, which is never long enough

 

Hahahah^

 

I do not have a datta logger but I do have a peak RPM recall. Sometimes I hit only 7100 and sometimes I hit 8200 momentarily. I am stationed in japan and our autox is called Enjuku. If I hit my apex wrong I will drop to a lower gear to rocket out of the corner. One way to increase throttle response is change your rearend gearing to a higher numeric, example going from a 3.90 ratio to a 4.56 ratio helps the engine rev faster because it reduces the vehicles perceived weight. If the engine doesn't have to work as hard to accelerate this will help in reducing lag. You can have gears purchased and installed for less than $500 bucks. Or you can start with a new platform like a GTR skyline.

 

yeah a shorter final drive would be a good upgrade, and for <500 its pretty reasonable. i wish i could get a GTR. (either one) thanks for your input, it was of some help.

 

I don't know where you live but, I have a friend here in japan that exports skylines. He is currently shipping an R33 GTR built by TopSecret back to Florida. He does have a nice project car, an R32 GTR. The car needs some work but for $1500 it's a great start. I purchased my 1991 GTR for $3900. It had over $3000 in upgrades when I bought it, like HKS coilovers, NEOVA tires, MOMO steering wheel, strut tower braces, drilled/slotted rotors and rebuilt turbos. He can ship and do all the legalizing for about 10 grand. Not bad considering my 1991 GTR went for $45,000 when it was brand new. I sold my S-13 when I found out how cheap cars are over here. It would take 10 grand to get my s-13 to perform like my skyline. Don't get me wrong I still love the S chasis. I might even pick up an S-15 before I leave Japan. That's right S-15!

 

^see thats how it should be down in the States. but since im in Houston, TX its not really possible for me to get deals like that. you said he can "legalize" them, do you mean get them legally registered to own and show but not necessarily legal to drive on the streets due to saftey and smog regulations? ive heard alot of stories and horror stories of "legal" skylines in the US, or TX at least. and unless you pay in excess of 20k and buy two skylines, (one for safetey testing) it will never be legal. no matter what. due to the chassis reinforcement and safety issues. but oh yes given the chance to get and R33 GTR i wouldnt hesitate at all.

 

You can legally import and register 96-98 skylines as long as they go through an approved RI.

 

Okay here's a brief run down. The only reason 96-98 skylines are considered legal is because Motor-ex petitioned the NHTSA after being threatened by the Gov. Before that Motor-ex was grey importing skylines, that's why you see some R32 Skylines running about. Grey market importing is still legal, it's just that law makers have already past bills and regulations. It would take more money and court cost to pass more regulations. There are legit companies like Kaizo who has found the most legal way since Motor-ex to import. All in all it's still grey market. You name any car made in japan and it can be imported for under $12000, Tax, Tag and titled. If it was truly a safety issue do you really think a 1989 Yugo would out crash test a 1989 R32 GTR Skyline? Ive been researching this stuff for over five years and I've seen skylines imported in every way possible and not one person I know has been forced to export their car. Hell Paul Walker even has an R34 GTR.

 

Motorex only got the 96-98's approved by the nhtsa and were importing all the other R32 r34 skylines as 96-98's MY skylines. All in all only the 96-98's are federally legal. I think everyone has seen R32, R34's s15's etc on the street. There are various ways to get them registered but that doesn't mean they are legal.
The bottom line is the 96-98's are the only skylines on the nhtsa import list. The chance of the feds finding out is very small.

 

^yeah thats what i thought, only the R33's are pretty much "allowed" in the US now.

 

why 33's

 

Not to offend anyone but let me put this in an easier perspective. I'm sure everyone has seen pontiac fiero Lambo kit cars and street legal fiber glass dune buggies. These cars are 100% street legal. Now, in terms of importing a car that does not have a drive train or unapproved glazing can be shipped legally, trust me it's on the NHTSA website. When the car is in this state it is considered auto parts. Now you go to your states DMV website and apply for a kit car title. Only so many per state are given out per year. Now you need a donor car like a wrecked 240sx with a clear title. Pretty much swap the vin tag or rivet the new one next to your BNR vin tag. In the case of the fiber glass dune buggies, they remove the VW Bug VIN off the center tunnel and then they rivet the VIN tag to the firewall of the kit body. You will need a Master certified ASE mech. to sign off on your DMV kit car application stating your new untouched unmodified skyline is road safe. The only down side is you may be limited to annual milage depending on your state, any where from 5,000 miles a year to 20,000 a year. But who's gonna use their GTR as a daily driver? That's grey as it gets and it's just as legal as the posser driving a Lambo kit car. The only difference is you might have a chance at beating a Lambo.

 

Need more proof? Go to www.kaizoindustries.com