My88Se

iTrader: (10)

How exactly does a s5 T2 intermediate housing make an NA "come alive"? Does this work on all NA's?

Jimmy325i

The S5 TII intermediate housing has a thicker casting at the port and a larger port to begin with. So you can port that housing far more than you can either of the S4's. (n/a or turbo)

For example... I might be able to get my thumb in the old S4 n/a housing. I can get two fingers in the ported TII. (and I don't have small hands) It's likely just short of a 50% difference in port volume. So right there, the flow has a potential of greater than a 25% increase for the motor. Add that to the gains made from enlarging the runners and opening up the 4 remaining ports and you'll know why I beat turbo'd cars daily.

Unfortunately, I never had a chance to get her to the track after rebuilding the motor in late september. I figure this thing is running mid-low 13's right now. I still have fuel delivery issues I've yet to address. I want to see 12's before going either turbo or adding a 175 shot of juice. Before all of you raise the bullshit flag... Keep in mind my car is stripped with an aluminum hood and LSD. It still weighs 100lbs more than I want it too @ 2400lbs.

87racer

how much does one usually cost?? do you know where i can get one??

Jimmy325i

I know where NOT to get one, but I can't post it here because of potential legalities. They're also either afraid of me or trying to do the right thing after what happend in our deal.

Try rotary resurrection or some of the other places dealing with lots of blown motors. Keep in mind you want the S5. The S4 doesn't have the thicker casting so you can't hog it out as much. There's no EGR passage cast into this housing either so you don't even need a block off plate. You'll need to run a header to make sure the ACV passage doesn't have any gasses going into it also as the TII housing doesn't fit the N/A lower intake manifold perfectly. There's a gap where the EGR passages transfer to the LIM. It poses no problems as far as the intake runners. Everything that needs to work does.

As far as price. Somewhere around 100 bucks is fair as long as its useable in the condition its in. (not needing machining or already having been lapped) 50 if it needs work.

87racer

cool...so how would i take care of the gap?? should i get a different intake?? isnt the S5 intake better anyway?

Jimmy325i

Nope stick with the S4 intake for this motor. The longer runners make this combo what it ends up being. (hella fun!)

The gap actually prevented me from dropping my motor in the night I got it rebuilt. (scared the **** out of me really) Turned out that with some creative induction of compressed air I was able to determine that there was no leaks due to the inlet for that plumbing being plugged by the header flange. (nothing goes to it because of the two blockoff plates. first being the ACV block off and the second being the header flange itself)

So after being significantly convinced (and having pulled the intake off again to double check my theory) I bolted it all up and dropped it in. No leaks! So as long as you run a header you'll be fine doing this. You'll need a header anyways to get over the 200hp hump anyways. I have so much pull at 4K people swear I have a turbo. Lots of people wont race me because of how badly I smoke their friends. I have a 1.3L N/A that hangs with the LT1 big boys and its not even tuned yet.

OH.... You'll be seeking lots of fuel mods after doing this to your engine. I was running way lean on the freeway (I have a halmeter) before getting the S-AFC and had to pound my fuel pressure regulator a bit to fatten it up. Now I'm back to stock fuel pressure (parts cars are great) and it runs like **** regardless of how I have the S-AFC tuned. The fuel pump is only good for power to 8134rpm if you have it rich and 8412 if leaned out. She falls flat on her face at the fuel cut, but pulls like an ox up untill then. I'm looking forward to power well over 9500rpm when I upgrade the pump and injectors.

Jimmy325i

Oh, and when I say it runs like ****... I mean that the halmeter is never happy with the fuel delivery. I can't get it to run in the a/f range everyone says to be in for max power. I get it pretty close but never high enough. The engine itself runs great! No problems after having some trouble (nowhere near as much as some) getting her fired off the first time. After the first 20 miles of break in she's never flooded (go figure) or had any trouble starting.

87racer

well basically im wanting to know how to get my car to fly by those cocky mustang GT boys. I figure that with a ported engine with my borla exhaust and k&n i should do ok. but it sounds like im gonna need to take my ACV off which means taking my air pump off which means taking my cats off. kinda scary for our California emmissions. instead of a header could i use a turbo manifold? will that do the same as the header? and with this new housing will i have to take off the air pump?? im trying to stay relatively smog legal. i hope i didnt get to confusing here, sorry. thanks

Jimmy325i

A turbo manifold will not mate to the 6-ports.

What you could do is leave the crap looking functional on the outside and make block off plates fitted behind them with the gaskets. (pretty sneaky huh?) You'll need to do a lot more to get free'er flowing exhaust than just a midpipe. Gutting the cats would be a start. I'm not sure how well your engine can breath with that much restriction on it. You're limited in power by how much air you can pump and if there's something on the back of the exhaust manifold that doesn't flow well you wont be able to shove as much fumes down the hole. All resulting in choking the power potential.

How about saving the stock exhaust for when you go get smogged? I know its a bitch to swap out, but its also the fastest way to 30+ more horse you'll ever find.

I'm not even remotely hesitant to run mustang gt's. They're all slow....

87racer

well then i think ill just do the header then... thats much easier anyways. but i still need to take off my cats then dont i? ill just buy the cats part of an exhaust out of the junkyard and knock out the cats so then i can just bolt my performance cats on whenever i need to smog it. cool this way i can beat all my friends and still just have a silly little n/a. so... i should get the s5 turbo intermediate housing for my 88 n/a and rebuild and have someone (hopefully you) port it for me. then get a header and my new little "cat setup", and my S5 turbo tranny. then ill do the TB mod and put on my ported intake manifold. oooooo...and then even later i could do nitrous!!!! yeah!!!! WHOOOO HOOO!!!!

87racer

bump bump

StukThrtl

Jimmy325i: Can you give us a detailed list of your mods? I'm looking into upgrading the rex next year and am curious what a good strong n/a combo would do.

Well, they're not all slow


Shawn

87racer

yea jimmy.... i also would like to know this race winning combo. im looking on having my other engine out pretty soon.... maybe by thursday, hopefully at least by next weekend. are you still interested in porting my engine? or should i just have someone around here do it? let me know how much $$ you're gonna want for this cuz i think my dads co-workers are rx-7 fanatics and they may be willing to take on this project...and no offense but nothing beats free, especially when you're broke like me. well pm me with details.... thanks

TriTurboGen3 RX-7

Jimmy325I, You have inspired me, i had been looking into all N/A power, but not sure the best route.

Do you know where i could get Templates for a HUGE *** Extended port. ?

besides more fuel/air, what would i need to rev to 11,000 ?

Jimmy325i

Well, Part of the wining combo is that I know I don't get traction above 1500rpm so I never hard launch. I ran with the `02 Camaro SS from a soft start because I didn't think he'd play. (boy was he pissed when he couldn't pull on me though) I would've had him if I'd just decided to tear off the line and see if he'd follow. We were dead even till 80 when I backed off. (40mph speed limit city street and my cop detection instinct was telling me "not smart")

So you guys want to know how I pull this off huh? hahaha Because I've been modifying cars for 11 years... I read every magazine I could get my hands on about cars when I was a little kid. (I think I'm one of few people who checked out every issue of hot rod from my HS library) I also have many friends with much more experience than I have whom I've payed attention to over the years, and have learned what works to make power. This is my first rotary. I'm loving that these little motors have two power strokes per revolution of the crank. (same as a v8) I also love the 10.5K bone stock "absolute" redline. Stock porting falls on its face at about 7K so don't wind out your stock motor that high because its not doing you any favors.

My list of mods huh? Lets see if I can remember all the crap I've done to this car. I've only had it a little over 6 mo's and have also been broke the entire durration of that time, so it's been tough piecing this thing together.

Car: `86 base

Engine: S4 6 port with TII intermedaite housing. Jumbo ported by me. Port matched and ported lower intake manifold. (still not convinced hoging out the runners elbows is a good idea as dre_2000 wrote up) ACV block off plate, air pump actuated 6-ports, RB header and full open 2.5" exhaust, (the open exhaust actually caused me to lose bottom end torque before porting the engine) TB mod, oil thermowax shimed, rats nest removed, 3/8" fuel line from filter and return line @ firewall to the rails, BACV removed, (not sure if this is causing my sporative idle problems yet or not. so don't do it) S-AFC, custom cone filter adaptor, (welded it up from steel tubing) and perma-cool heavy duty e-fan.

Chasis mods: removed all unneeded crap such as the plastic bin shelf, insulation from all interior panels and carpet pieces, rubber trunk mat, A/C system except the evaporator in the dash, (haven't gotten to it yet) Porsche 914 valved koni's in the rear (got them for 26 bucks new, because I couldn't launch for crap with all 4 shocks being toast) I'll put a set of properly tuned shocks on all fours when I can afford to. LSD from a GXL, custom short throw shifter, (2" from bumpstop to bumpstop) removed the metal for the rear speaker pods, removed the little brackets for the jack and tire iron. (still running an aluminum spare) And my car came stock with the aluminum hood. (I'm a lucky bastard cause I got the car with the blown coolant seal for 400 bucks)

I still run the 14" phone dials because I don't have the $$$ needed to get my 16" spoon replica's (which weigh 13.5lbs) Inertia kills races. Rotational inertia especially. All these guys running 17' rims that weigh 20+ lbs are shooting themselves in the feet. It takes so much power just to turn over that extra weight that they have no chance against someone with a lighter more carfully designed car. This is exactly why I beat cars with 100 horse more than me. The car weighs 2400lbs. I'm also probably close to 200@ the wheels.

As for porting housings... I know free is great (my LSD was free) but the porting on your engine is the single most important factor in making power. If your dad's buddies aren't familiar with rotaries I would advise against having them touch them. Many people on this forum will tell you that the port shape is 10% of the equasion and there's a lot of truth in that. What happens to the air before it reaches the transition from port to chamber is probably more important, but the port shape will also determine the overlap of the intake and exhaust and whether or not you'll leak oil. (one of the oil control rings rides pretty damn close to the intake port)

You can have those guys do your exhaust though. N/A exhaust sleaves need the diffusers cut out of them and its a long slow painfull process. (even though it doens't really take all that long but it feels like it) <--- read as I don't want your rotor housings for porting.

I'm only aware of the RB templates and didn't purchase them for the simple reason that they're far too conservative, and I think they suck for that reason alone. RB makes some damn fine products. Their templates are not one of them.

I used my brain in determining the best porting for my engine. Looking at all the availible pics of different port profiles and realizing that how the port throat is blended into the port opening makes as much of a difference as the shape of it, (to an extent) I followed my insticts when porting my engine. Jokingly I named my engine the 13b-ZEN because I was kidding around one night with a buddy who was asking these same questions and I said "to make a powerful engine you need to let your desire for performance flow through your hands and into the engine and become one with the housing and it will become one with you and it will make you power" ...and thus the ZEN was born.

As far as price for my porting goes. PM me. I'm capable of doing the same thing again and again to as many housings as I can get. I'm also considering making templates for the 6-port but not sure there's really a market for them due to the fact you need a different intermediate housing to make the engine worth anything. SO anyone looking for porting just drop me a line. We can work something out I'm sure.

87racer

very nice, i think that my dad's friends are also rx-7 guru's. My dad tells me that that is all they talk about so they should know some stuff.... i should be able to tell just by talking to them if they are a wise decision, if they dont know **** then they arent gonna do **** for me. You are my #1 pic right now so ill let you know..... many thanks.

Jimmy325i

I just realized I didn't address the 11Krpm question....

The rotating assembly would need to be lightened or a 2 piece E-shaft would be needed with the center bearing. (way cool piece btw) Lightening rotors means lowering compression unless you can take material out of the spiderweb of re-enforcing inside the rotors. (good luck getting that to balance though)

I'll rebuild motors too. I'd rather that other people did them themselves because its a good feeling to have beaten someone only to go talk to them and say you also built your engine yourself and see their faces drop. Many many many many people think I have a turbo. I love it! lol I'm still thinking turbo might be an option, but it'll be a couple years.

87racer

im thinking about just buying a TII right now. it would be much easier than trying to turbo my n/a later.

Jimmy325i

N/A with juice will stomp turbo guts. Much easier to work on without all that extra crap in there too. If I get a stand alone fuel computer turbo might be too tempting to resist though. 400rwhp out of a little 1.3L is just too damn tempting for a daily driver.

87racer

turbo with juice will stomp all. it will just make more sense for me to do it that way. everything i want to do to my n/a i can do to a turbo with even better results. but i dont know... ill probably get in too much trouble with a TII...... i dont know dammit!!!!! any advice?

autocrash

go turbo....

Jimmy325i

Go 6-port turbo. You keep the N/A insurance rates and will save yourself from replacing everything on the damn turbo engine anyways. You also end up with more port timing for even more power!

I was talking about either going nitrous or boosted, not both. I kept the S4 rotors for their lower compression vs the S5 with the intention of using that as a means to squeeze more charge into the combustion chamber.

I forgot to mention that my total investment into this car is $1600. For another 2K I'll still be less than a TII and I'll have a built engine and all the upgrades for that price. I bought this car having learned from my BMW experience. Buy a car that has just the stuff you'll keep and get it cheap. Then spend the savings on getting the car where you want it. In this case all I needed was the chasis, some wheels, and a core engine to rebuild. My entire interior is likely going to be history. I want to see a fighting weight of 2400lbs with full 8pt roll cage extending to the front sub frame. I'm also looking into a fuel cell because even at 1/8th of a tank I can hold my accelleration long enough to get it caughing from starvation.

87racer

crazy... i want this to be my daily driver/V8 slayer so i think 2400lbs will be a little uncomfortable for me and my girlfriend. but i think if this TII doesnt work out then im gonna go for your super combination n/a.... heheheh cool name huh?? yeah but i think im gonna add a little turbo to it later if i dont get the TII now.... If i do get the TII im gonna turn it into a sleeper. that should be fun.

Jimmy325i

Did you miss the ZEN name earlier?

I've got a decent T3 lined up for free. If I end up going with the stand alone computer it'll be hard not to go turbo from there.

87racer

yea... thats what im gonna do if this turbo sale doesnt go through.... id really like to start with a fast car and make it even faster.