RB25de Insane Supercharger Idea

[Trini.Madman]

Hey guys/gals
I'm very new to this forum and I was wondering if you all can give me some assistance.

From my name you all might notice that i am kinda mad... With this idea i want to do, will verify this

I have myself a RB25DE (non turbo) engine Series 2 (no ignitor box). Correct me if im wrong, but i believe that this engine's compression ratio is 10:1. That being said, I want some more power ofcouse . Just as we all want more power. However, I am the type of person who ... HATES! turbo lag. HATE HATE HATE! Ive driven many of my friends cars and no matter what they try, unless the engine is a perfectly stock engine with stock SMIC, the lack is the worst and i hate it.

That being said, I looked towards a solution that will avoid lag and avoid the heat that a turbo charger gives. I consider the heat from a turbo in-efficient. After illiminating NOS and some other stuff, i decided i like the idea of alot of lower end power. Acceleration and not just top end (with alot of lag).

Doing some research and talking to a few people, the best solution so far seems to be a Generation 3 Eaton M90 Supercharger. Even with a 1:1 pulley setup, this thing would be boosting the engine. Now with that being said, The plans i have are as follows, and I would like you all to see if my thought process is in the right direction.

1- With boost, i'll need a better than stock exhaust. So i was thinking to build an extractor manifold which would go from 6x1.75" to 2x2.5" to 1x3". I do not believe anything bigger would help flow of exhaust. Also, i will heat wrap the exhaust atleast until under the door to prevent as much heat from the engine room.

2- The stock intake manifold would be taken out just to polish and use because the aftermarket intake manifolds are geared towards high range power and the stock is very nicely designed for more midrange power.
This is my source: http://forums.gtrcanada.com/gts-tech/39 ... pment.html

3- To keep intake temps as low as possible, i will be installing a SMIC (stock skyline) and i intend to add a watermeth kit for when boost reaches past 5psi.
---- To again improve cooling, i intend to install a 5core radiator with electrical fans and an engine oil cooler AND i will be installing oil squiters on the block to again aid with cooling. (really hate heat)

4- With those bases covered, an Eaton M90 Gen3 Supercharger will be set to between 8 to 12psi. I hope to be seeing full boost at about 1500 to 2000rpm.

5- I intend to get some 550cc side feed injectors to replace the stock injectors and a Aem F/IC to work with a RB25det ECU i will be using.

6- Ofcourse fuel pump will be upgraded, head studs will be changed and maybe a slightly thicker Cometic head gasket might be used to slightly reduce compression ratio.

Please keep in mind the lower RPM performance i am looking for.
All opinions will be greatly appriciated, and all i ask is please dont tell me anything about a turbo. I dont like them or i would've gotten an RB25det in the 1st place.

Questions:
1. Would the STOCK internals handle the low end torque i am looking for?
2. I learnt that the rb25de should only see 10psi because of the compression and detonation capabilities after that, but considering the dramatically lowered temps because of a supercharger instead of a turbo and the added water injection, would 12psi be safe with just a headgasket and studs?
3. After confirming that i am mad, please tell me if i should also include some AEM "Smart Coils" while doing all of this.

When the project does start, i will be keeping you guys up to date on progress and pictures will be posted.
Thanks for all opinions and thoughts

[Darius]

Crazy, but yes, yes, and yes the coils will likely need to be upgraded.

[Trini.Madman]

Thanks for the reply! So my fingers are crossed for the internals really standing up to the punishment. My fingers and toes are crossed that its reliable afterwards. I'll need some help with tuning because I intend to do it myself. Any advice on tuning it? proper AFR's? MAF clamping? Any help will be greatly appriciated .

[Darius]

At 12 psi, I don't think it'll be a problem. You'll obviously need a good tune to make it work reliably.

[Trini.Madman]

This is the information i need.

What is considered a good tune? I don't intend to be a professional tuner or anything, but there is not much information on the actual tune the engine should be looking at. I saw somewhere in someone's project that their AFR went from about 14.5 at idle to 11.5 at 3500rpm where they had full boost and this held until limit. Now another set of research said that the most ideal AFR for a car in boost would be between 12.5 and 13. So, i was just looking at explanations as to why the Ratios conflicted so much. Now i know most vehicles will idle at about 14.7 AFR. So what i need is help with what kind of tune i will be looking for. What limits would i need to work within to get a really nice tune. Keep in mind i will be doing this on my own. I will have my dad drive the car while im in the passenger seat doing the tune.

I hope i am not asking too much information or asking things you cannot answer, so please tell me if im over doing it.

Thanks!

[Darius]

If you are planning on tuning this yourself, you should really find someone who knows what they are doing and can help you out. And to do this, you will need a standalone EMS.

Since you are asking about why the AFR changes, I'd strongly recommend having it professionally tuned.

[Trini.Madman]

Ok i don't think i explained myself properly. I understand how turbo's work and how they boost and why the fuel ratios go to 11 and stuff.

What i'm trying to get at is that its no longer a turbo here.
One major reason for going rich with the mixture is to cool the pistons down right? But with a charger, intercooler and water injection, the temperatures will definately not be as hot as a turbo. I also understand that with going rich you burn up as much of the oxygen as possible.

I have done my research ( running almost 6months now of research ). That why i decided to come here and ask for opinions, suggestions and help. I intend to use the Aem F/IC to tune. It seems to be straight forward so far with what it does and its limits. Where i'm at, it'll cost me $10,000 for a Standalone vs $2800 for the aem.

Ive been into cars really long and all ive done repairs on and tuned is turbos. Everything in this world is turbo based right now down here. So other than looking for something really different, i think i need as much advise i can get and as much opinions to put my project together.

My final project is to actually bolt a turbo on, with the charger, but maybe a GT40. And do internals and go big. So i get the horsepower without the lagging acceleration. But im definately no way close to the cash to get a turbo. Funds limited me to the Charger so i thought id take what i can get for now and run with it. Charger = plenty low end and acceleration. Thats going to give me alot of fun for the while

Just options, opinions, advise. Thats all im asking. Also, i really refuse to go to a "professional" down here. A friend of my bolted a GT30 on his rb20det and for the love of god, 4 "professional" tuners stole approximately $8000.00 each from him. i eventually went back to basics and he was really surprised that I could improve what these guys were trying to do on a dyno, i road tuned... He made about 350hp with those tuners and i managed to put him at 427hp when he went back to dyno... So its not that im stupid or anything, its definately not rocket science, the guys down here are lame and I prefer to do it myself and save the money...

[Yellow4g63]

Why even bother with the stand alone? Why not just use a real time ecu like Nistune. Why not compound turbo your car.

[Carl H]

10:1 compression will knock like hell with boost more than 10psi unless you're on some exotic fuels.
and the fic will make you want to poke your eyes out with a rusty fork, dont work well with nissan gear.

[Trini.Madman]

Why even bother with the stand alone? Why not just use a real time ecu like Nistune. Why not compound turbo your car.

Ok, Explain to me Nistune? Have a general idea, but price?

10:1 compression will knock like hell with boost more than 10psi unless you're on some exotic fuels.
and the fic will make you want to poke your eyes out with a rusty fork, dont work well with nissan gear.

Ok Carl, i understand, but with a metal head gasket, it will reduce the compression ratio... maybe 9.5:1 or might be lower... will get a calculator for exact reduction in compression.

[Yellow4g63]

www.nistune.com they might have a daughter board for your ECU.

[Darius]

E85 loves 10:1 compression

AEM is a standalone but you shouldn't even be paying $2,800 for it. Nistune will probably get the job done in the least costly manner, but I've never used it so I have no idea how easily it logs/tunes, etc. compared to other systems. Nistune is hardware and software that allows you to use the factory ECU for tuning via a laptop. The laptop logs the data and displays it so you can analyze it and adjust fueling and timing as necessary.

[Carl H]

true but e85 is an american phenomena, he's not going to be able to find that in Trinidad.
also cant get too crazy by lowering the CR with a thick hg, you'll end up messing up the squish and it could knock even more!

[Trini.Madman]

Ok Darius, the AEM F/IC is a piggyback system. Check it out.

http://www.aemelectronics.com/engine-ma ... r-f-ic-12/
If they promoted this the right way, then from my understanding, it'll allow me more than just what an SAFC will do. It should also allow me to get alot more out of the ecu than the ecu would be willing to give, i'd just need to spend alot of time tuning it right.

Also, from this site, if their calculations are right,

http://www.kb-silvolite.com/article.php ... ad&A_id=57

My final compression ratio will be about 18.2:1 IF i have 12psi in my 10:1 compression. Wouldn't the Water Injection help with reducing the knocking? Also, another site said that above 10psi i might blow the OEM headgasket, if i just replace it with a cometics headgasket and ARP Head studs, Shouldn't all those factors give me a safe environment for the pump gas?

Ofcourse if the block wouldn't handle it, i will back off the boost. But my fingers are crossed that i don't have too.

Also, the $2800 is TT dollars which is almost 6.4TT to 1USD. But my point is, dollar for dollar, it feels like s*** to pull out $10,000TT for a standalone.

By the way, loving all the information I am getting here! Thanks very much so far, you all have been awsome help!

I think I will try the 12psi and if i cant get it working properly id reduce it to 10psi.

Next question on the list. Should i go with 550cc injectors or 740cc? Which would be better for my application?

[Yellow4g63]

save the piggy back rides for your girl friend when she is too tired to walk. Get the nistune and make it do what you want without trickery. You would want to do meth injection. Water will prevent the knock but take some hp away from you. The Meth won't rob you depending on what you use. Windshield wiper fluid depending on the brand could be + or - but still prevent knock.

[Carl H]

FIC can only retard timing, not advance...and the stock ecu isnt exactly loaded with the best maps out there.
if any kind of piggy back, you'll want to go with an emanage ultimate and the greddy map sensor.
clamp the maf signal and tune based off of pressure input.

[Trini.Madman]

save the piggy back rides for your girl friend when she is too tired to walk. Get the nistune and make it do what you want without trickery. You would want to do meth injection. Water will prevent the knock but take some hp away from you. The Meth won't rob you depending on what you use. Windshield wiper fluid depending on the brand could be + or - but still prevent knock.

Ok did some digging with the nistune. Seems to be very user friendly and i will be able to do it myself. Major problem with it is that it comes from Australia AND that would mean ALOT of $$ to ship it half way across the world! As for the lost with the Water Injection, i'll have to live with it because methanol isn't as readily available here for good prices. Maybe if i find a windshield washer fluid that will do the job but other than that its water...

FIC can only retard timing, not advance...and the stock ecu isnt exactly loaded with the best maps out there.
if any kind of piggy back, you'll want to go with an emanage ultimate and the greddy map sensor.
clamp the maf signal and tune based off of pressure input.

Ok Carl H! Now I like how you are thinking! But i need you to explain something for me. Why would i need to be able to advance ignition with what im doing? ( asking a genuine question here please explain with detail ). From my knowledge, when under boost wouldn't you need to retard timing to avoid detonation? I understand timing needs to be advanced when accelerating, but wouldn't the stock ECU have a good enough mapping that i won't really have to mess with it much? I was really looking at the FIC for 1-Price. I can get the Aem F/IC for $2850tt and the greddy e-manage ulti for $4500tt... All i thought id need the FIC for is for injector control and Clamping the MAF sensor? Correct me if im really wrong please?

This is the kinda reasons i came here to ask all my questions! Been looking at the site a long time and i see the kind of information thats available and i really wanna learn.

Thanks again

[Trini.Madman]

Hey guys. Did some digging with the Nistune stuff and realised that for the Nistune to work on my RB25DE R33 Series 2 Engine, I will have to get a Z32 ECU and do some modifications. This will be very very difficult for me to make happen. A Z32 ecu is already impossible for me to find locally. I am willing to do the modifications myself, but finding the ECU will be an issue.

Did alot of digging on the Aem F/IC vs the Greddy E-Manage Ultimate. Honestly, for the price difference and the few gains on the E-Manage, the Aem F/IC seems to be the better choice for the use I will have for the tune. I will keep researching all I can for the information I need, but this is where i have reached for now.

Just keeping you all updated.

[Trini.Madman]

Hey, no replies in a while. Just wondering if you all think i abandoned the project?!

Cause I need some more information...

On the RB25DE series 2 block, If i am to add oil jets/oil squirters to the block, is it a simple process or would i have to tap into the block?

[Yellow4g63]

If it's like the SR20DE then you have to tap the block.

[Trini.Madman]

OK so i guess maybe you guys got bored of my idea.
However, its finally starting to fall together.
Things i've decided to do.

-Going to Stock RB25DET 370cc Injectors. Did the research, they should be good for my power range and Boost level. (Fingers crossed on keeping less than 10psi in the engine)

-Also, im going to custom make my oil cooler, so that part will probably come about later on.

-Going to get the AEM Smart Coils but probably not immidiately its going to be the 2nd most expensive component, 1st will be the water methanol kit. Think i'll leave both those for last just before i start the engine.

-Going to get myself a RB25DET Stock Pressure Plate and Clutch disk. Its cheap so i'll try it out and see what can happen. If it doesnt work, i'll get something Heavy Duty.

-The other MAJOR thing im changing is the Intercooler. Taking that OFF all together. Going to go straight from Supercharger to Intake Manifold and Spray the Water Meth before the charger to keep the charger itself cooler, i suspect it'll work out better that way because i'll illiminate some very minor lag and i'll buy less parts.

-Going to build the Extractor manifold at home. My dad is a wielder, so he'll be able to help.
ANYONE KNOW ANYTHING ABOUT THE TUNING OF AN EXTRACTOR EXHAUST MANIFOLD, I WILL REALLY APPRICIATE THE HELP ON THE SPECS FOR IT

-Also, keeping stock Headgasket for as LONG as possible. IF or when it blows, i'll change it and go metal with ARP studs, but until then, im keeping the engine closed up.

Ok that is my present update. Going to start on the engine probably tomorrow. Clean it out, going to dismantle the alternator, powersteering pump and compressor and clean the block out. Then pressure wash the head and might paint the block with some bright paint so i'll know if im getting any leaks. Time to get this thing started.

Also, i am going to buy the SC probably soon, so it'll be here by early january hopefully.
Staying with AEM F/IC.

[Carl H]

skip the aem smart coils and just use the standard gear, in good shape it will fire thru 700+ hp air charges.

KEEP THE INTERCOOLER as roots blowers are notoriously inefficient and generate massive amounts of heat...water meth alone will not drop charge temps down to reasonable and you will get knock.
you will also want to spray AFTER the blower and AFTER the intercooler (to avoid condensation problems) as spraying before the blower will erode the coating on the rotors and eventually the rotors themselves, not to mention water isnt very compressible and could hydrolock the blower.

run the stock rb25det ecu as it has rather conservative timing maps which should be ok with the blower, you could probably (not ideal) run just the stock ecu and be fine as it is just mad rich all over the place.

if you havent already got one, get a wideband and an EGT gauge for tuning!

[Trini.Madman]

AHHH! A nice informative reply!

So think the side mount intercooler will be sufficient? because im avoiding lag as much as possible...

Also, im going with the RB25DE non turbo brain, but the AEM F/IC has retarding ability with ignition so i think its a tuning matter there.
I will get an AEM Wideband with the AEM F/IC so that should handle tuning.

So keep side mount. Any advice on the size of piping to use?

[Trini.Madman]

OK so Thanks to CARL H who showed me how to upload pics!
So here they are!


So i took off the Exhaust manifold first because i needed to move the engine from where it was. (might notice the grass and dirt it was in from the other pics)


I noticed some oil on the #6 outlet and got a little frightened


Only to figure out that it was oil leaking from the tapit cover. Think i'll change those seals one time.


This is what the #6 outlet looks like from up close. Valves seem to be in great order


Saw some oil on top of the #3 intake valve and was hoping that it came from when the engine rocked or dropped during the accident the car was in. Was a really horrable accident. I will find out when i fire this baby up the next time!

Thats the most update for now. SC is being ordered hopefully it will reach here in about 3-4weeks. With that on hand, i think i will try to mount the charger on the engine and start building my extractor manifold for the exhaust. still figuring the exhaust specs exactly. Will get around to it as soon as possible after checking the original exhaust sizes etc.

[Carl H]

best bet is to link using an external host, i use photobucket.

[Trini.Madman]

Ok guys I need some advise/help.

I am getting ready to design the exhaust system for the car. Now i am trying to stick to a really "sleeper" "stealth" look and sound. So what i came up with so far is an interesting exhaust design that i will like your opinoins.

I will love the advise especially with the sizes of pipe i will be using.

My initial thought was to go with a 6-1 extractor design. This became a bad idea when i realised that i'll have to have a 3inch exhaust running down my entire car. ( a 3inch exhaust is very easy to spot from a few feet behind the car ) Idea was washed out.

The 2nd idea is the craaazzzzy part! again refer to my name! Madman!
I thought about going from 6 into 2 into 1.
the 6 cylinders will feed into 1.5inch piping each for about 2-2.5ft (24 to 30inches) ( any input on this will be greatly accepted on the size and lenght)
The 6 pipes will feed into two 2inch pipes. (3-1ea). But the interesting part is im thinking to run both 2inch pipes to the back of the car and then use a 2x2 to 1x2.5inch adapter to bring in the final barrel. Ofcourse along the route i will put in 2 silencers on the 2 inch pipes to quiet it down a lot!.

I know its a crazy idea, but what i want from you guys if the advice on sizes and if it will work as i expect it too.

My experience so far suggests:
-larger pipe = more noise to cover up (difficult)
-dual 2inch exhaust will be much quieter along with a nice barrel stealthy barrel should shut it up alot.
-and the 2 inch should be large enough to pipe 3cylinders down the car efficiently. (lets say im running 8-10 maybe 12psi boost. Tell me if 2inch is too large for 3 cylinders)

For the sake of argument lets remove the cost factor. Lets talk reality. practicality and efficiency.
And keep in mind that im using a supercharger and not a turbo! so i'll have no backpressure like what the turbo will provide by just being there!

[Yellow4g63]

Look up the aftermarket they sell for the rb25de and just copy it or buy one.

[Trini.Madman]

Yes i saw those, but there are 2 basic designs. And both come down into a single 2.25 or 2.5inch. Im thinking really silent compared to them. The car had a 2.25inch exhaust before it crashed. With 2 resonators, a silencer and a quiet barrel, you cudve heard me from home until i reached the corner when i launched... dont want really. Also edited the previous post

[Trini.Madman]

Hey guys, good news, bad news.
Good news, my car is fixed and im back on the road.
Bad news is that the RB25 supercharger project is going to be put on hold for a while.
Cash isnt the problem its just that school is about to start back in january and with the workload im expecting i'll have absolutely no time to spend with such a lard project.

Instead i am planning on a rb20e engine might do some small things. will see that in another thread.

TY for all the info so far i will be coming back to this project in the future! please dont delete thread