Silverbullet

hi i'm thinking about buying a 1987 rx7 that has a leaking coolant seal or something of the sort. apparently its a common thing for these motors. i'm new to the whole rotary thing.

i was wondering about how much it would cost to have it rebuilt by a shop.

im 99% sure its an na motor, but thats pretty much all i can say about it. if i build it i'm hoping to add a turbo setup and get anywhere between 200 and 250 rwhp.

so i have a few questions.

1) how much for a regular rebuild to repair the damage?

2) how much for a rebuild with mildly built motor and turbo?

2b) is it even a good idea to slap a turbo on a na rx7 motor?

3) does anyone have any suggestions of other things to do while the motor is out and being built? what about porting it? etc... looking for things that would be pretty cheap and effective in either durability or power.

now i'm HOPING that if i went with a mild setup, pushing lets say 220hp... i'd probably be looking at a $2000-$2500 job? how far off am i?

Silverbullet

i'm trying to get the ball rolling on all this within the next few days. quick responses are greatly appreciated. also if anyone can recommend any shops to take it to in virginia w/ cheap prices + do good work, let me in on it preferrably near va beach area because that is where the car is sitting.

BlueTII

If you are thinking of "slapping" a turbo on an N/A engine, you would be much better off having it rebuild with turbo rotors. This allows for higher boost levels/more power then the N/A rotors.

Silverbullet

yeah thats what i collect from what i've read... im pretty sure i've read just about everything i can about these things, but for some reason i just cant put 2 and 2 together and really figure it out.

can anyone give me a general walkthrough and ballpark pricing?

BlueTII

Do you plan on removing and installing the engine yourself or are you looking for a local shop to do it? I can quote you a rebuild , with and without mods, email me at csanders@banzairacing.net

Silverbullet

emailed. thanks

still any advice will be greatly appreciated. (anyone else?) i'm trying to get as many opinions as i can

iceblue

That is entirely incorrect.

And to poster Kevin Landers of http://www.rotaryresurrection.com/
is near that area for you. If no internal damages exist it will cost you around 1 to 1.5k for a rebuild + porting. Turbo setup will jump that up. If you are going to turbo Kevin could start the prep work for it like removing the 6pt sleeves and the actuators and blocking them off. Or port matching a TII manifold for you if you chose that rout. If you don’t like this 1Revin7 has a custom turbo manifold that allows you to bolt on a turbo with the NA stuff in tacked. The cheapest rout would be Kevin prepping for you. It is all up to you. Whoever you chose should be able to walk you through EMS options and communicate what is best for the setup you chose.

Silverbullet

you guys are awesome im gunna go check that out keep it comin if anyone has any more help or ideas

turtles87rx7

hmm i hope i am not "thread jacking" as they call it but i am intrigued by this custom manifold by 1revin7, is there a thread about the manifold or pricing or anything??

BlueTII

[QUOTE=iceblue]That is entirely incorrect.

Actually you are incorrect. To push enough boost to reach his 250 hp goal he should run TII rotors. High compression N/A rotors cannot handle high boost pressure for very long, which would leave him with 0 hp.

iceblue

[QUOTE=BlueTII]I do not understand what logic you are comparing this to but it is entirely incorrect. I am not trying to be an *** but I will try and explain how this work.

No OEM rotors will ever create more over all HP then another. Yes he can run more boost on a lower compression rotor. This does not mean he will create or anyone will create more HP.

Boost raises the combustion compression. If he ran 8.5.1 compression rotors at 12 psi and made 270fwp he would also make 270fwp at 8psi on 9.4.1 rotors. Because of the raised compression you will make the same amount of power at a lower boost level. This also means faster spool.

His goal of 250hp will actually be far easier to reach on NA rotors then it will with TII rotors. Why? Because he will have to push the stock turbo past its efficiency range on TII rotors to reach this HP goal. However with NA rotors 9.4.1 and 9.7.1 he will be able to reach this HP at a lower boost keeping the turbo in its maximum efficiency range. This is based on a OEM turbo setup.

FYI:
SonicRat made over 450WHP on stock ports on a 6pt NA motor.
Aaron Cake is running a GT35R on a BP 6pt S4 motor.

JoshRX7

iTrader: (5)

Iceblue... I think you would concede (if you could get over your ego long enough) that 8.5:1 rotors are safer for boosting than NA 9.4:1 rotors. I'm not saying it can't be done and that it isn't being done this very day. However, I agree with Banzai... I think he will be giving himself a greater margin of error for boosting... and also the ability to increase his boost in the future with the 8.5:1 TII rotors.

I don't like it when people put their ego before telling the whole story. There are many examples of 9.4:1 rotors failing under boost on this board. Silverbullet, search for them. Besides, I usually don't take the "Mazda engineers know more than all" stance, but i will in this case.

Once again... is it being done? Yes. Is it being done today by a moderator on this board? Yes. Is it the best idea and give you the safest margins of error and expandability for boosting? NO. It's a trailblazing idea not for the faint of heart and carefree enthusiast just wanting a nice rebuild.

Josh

classicauto

iTrader: (3)

haha - that should be in the archives....

P.S. - I've only been working with these cars for a little under 5 years.........and I know jack ****.........I know stuff, but don't ever think you know or have read everything........

iceblue

Keep squeeling and I will keep hiting it harder.

You need to ******* read. I never stated to increase boost or run high boost numberes. I stated that it is not needed to run as much boost! It is common sense that you cant run the maximum boost that the TII rotors can handle.

This is just a stupid comment. There is hundreds of exsamples of TII motors failing under boost also.

I also never stated the safest margin. TII rotors would clearly be the safest margin. And this was not just towrds the posters rebuild it was a conversation with blueTII.

You should also look at another thread I started to help dispell all the information out there about this.

Next maybe you should consider this. S4 NA rotors are 9.4.1 compression S5 TII rotors are 9.0.0 compression. That is 0.4.0 differance.

JoshRX7

iTrader: (5)

Yea, well maybe you'll pay for his rebuild when he blows it up, chump. And I don't have 2,366 posts like you, dude, but I 've been around long enough to know you blow your mouth just enough to be dangerous. I think I'll have plenty of support on this one.

So what's your point? You're still wanting to use 9.4:1 rotors... not 9.0. Stick with apples or oranges.

And since you think my comments are so stupid, why don't you get your bandwagon of support on another thread and prove us wrong. I don't think my comments were particularly "stupid"... I was just trying to simply state there are examples of folks on here trying to mix and match, be a trailblazer, and they have ended up popping engines. There you go. It's not a stupid comment, it's fact.

So, you're going to tell him to use these rotors with no margin of error. Is he going to run 8 psi consistently? What if his wastegate fails, what if has general problems controlling boost? What if he goes out and gets the itch one day to turn up the boost? Would you be content telling him to use the NA rotors then... I hope the answer would be NO... drop the ego dude... you're notorious for it and you're leading a new guy astray.

And for those who don't know... Iceblue likes to give out just enough information to start an argument... then he likes to come back and amend what he's said with additional information like you're supposed to be able to know what he's thinking. And I don't really care what you think... it's a dumb idea... especially when you can take the 8.5:1 rotors and make as much horsepower as you want and choose a good ball bearing turbo and get as much spool as you desire. GET OVER YOUR EGO.

Josh

iceblue

Here I have something for you to fill your mouth with. You are just wanting to pick a fight and have never shown **** to back yourself up with. This was an argument about this and this alone. Now read it very well.

Now I say this is incorrect and he says I am incorrect. So I see a stand off someone needs to show more prove. I took the initiative to open a thread to hopefully shed some light upon it and come up with something bettor.

Now stop tooting your horn and try and see the value in each post. No one is carrying jack crap around. YOU ARE. Stop placing words and comments on people they have not said.

Once again this was not directly towards to poster it was about the comment ^ and to be used for a tool for the poster. Anyone who just takes advice or posts on the forum without researching them themselves is an idiot and deserves to pop there motor. Live and learn.

That’s not up to me. And there is no reason he can not run 12psi on stock T18s turbo.

Get a good boost controller and watch your gauges. Not my job.

Again that is you own idiocrosy.

Once again I never stated to go use NA rotors. I do not discourage it either. I only stated the 250 number with a stock setup would be easier to reach on NA rotors then TII rotors.

Now you need to stop leading yourself astray. Take your personal agenda to PM.

JoshRX7

iTrader: (5)

Yea, well, whatever... I think there's more than enough info here now for people to decide for themselves... have a nice day. And I don't have a personal agenda... you put words in MY mouth.

Well, one last thing...

"I do not understand what logic you are comparing this to but it is entirely incorrect. I am not trying to be an *** but I will try and explain how this work." says Iceblue.

Just how long will these NA rotors survive the extra heat of higher comnpression? There is quite a few mods to do to a turbo'd NA to even consider its longevity... it has to do with cooling. I'm pretty confident this was the logic BlueTII was following. I don't know what logic you're following.

Somebody light this thread on fire.

Josh

turtles87rx7

does anyone have a link to 1revin7's custom turbo manifold??

iceblue

Let me guess, you have never actually held a rotor in real life have you. Or a Turbo rotor and NA rotor. Well outside of the dish they are identical. So how is it you think this so called cooling problem is going to effect the rotors from blowing? Do you think they like explode or something? If you ever took a look you would notice that a TII has the same cooling system as a NA. If a TII can support 250hp why cant a NA? 250hp puts the same amount of stress on one motor as it does another; the intake charge temps only have an effect on detonation. As I stated proper EMS will have to be worked out. With this proper EMS tuning and fuel there will not be a concern for this anymore.

Anything else?

iceblue

I went and searched for the information for you about this. This is what you will need.
https://www.rx7club.com/showpost.php...7&postcount=13
You will need to PM him to get pricing.

turtles87rx7

thanks a lot

JoshRX7

iTrader: (5)

I didn't mean the rotors would "blow up"... I was mainly referring to the extra heat involved with higher compression... running boost in a 9.4:1 will create more heat than running boost in a 8.5:1. This will create more stress on all of the seals of the rotor... eventually, causing a seal failure sooner than the 8.5:1.

I can see the value of the higher compression rotors in certain race applications where every absolute bit of hp is necessary to compete. However, these motors will be maintained and used in totally different manners than a daily driver. I even understand that these higher compression rotors can be tuned appropriately to run in "safe margins", but they surely have their limits and heat from higher compression is one of them. And for somebody interested in boost, it also has its limits.

NOW... I apologize for any rude statements I've directed at you... I see your point and understand everything you're trying to say. I don't agree this is a good idea AT ALL for this guy... not when he can use a perfectly good 8.5:1 rotor. Also, I don't think this is an "all things being equal" kind of scenario... like I said... I believe you're looking at more heat with the higher compression rotors, and when is that ever good? So, we'll agree to disagree and let bygones be bygones.

Josh

iceblue

I think you have this backwards. A higher boost number will create more intake charge temps. As it will require more boost to create the same amount of power. But both have the same overall HP limitations, no one gets a higher margin.

If you look at intake charges heat increases with boost b/c the air molecules must be pressed much titer and this is like friction the harder they are pressed and faster the more heat that is generated. The higher the heat the more chance of knocking occurring. Knocking will pop a motor in no time, rotary’s seem to be less tolerant to it then boinger motors. The common failure is the rear dowel cracking. The intake charge is not directly related to the ability of the seals to withstand it or not. You may however reflect these temps in your cooling system but only someone that has monitored these conditions could comment accurately.

At 15psi the intake charges should be reaching 250F. If you made 300fwhp at 15psi and you made 300fwhp at 10psi with higher comp rotors the overall intake charge will be less with higher comp rotors. Either way you can never push it past the cars setups ability to withstand. No matter what setup if you abuse or push it past its tune and setup you will pop it. I will agree when you push the car to the edge you have very smaller margin of error with higher comp rotors.

I personally do not believe he will be close to that edge with a 250hp goal. With proper tuning and fuel I think he can make his goal cheaper with NA rotors. I feel this because you will more then likely being pushing the stock turbo setup past its safe capability’s on low comp. The NA rotors he already has "less money spent" and will give a few extra pony’s for nothing. Now if he upgrades the turbo and all that jazz then all bets are off.

Now I personally do not know enough to comment on the volumetric efficiency of each setup to actually give dead on accurate information on each setups capabilities and how they will function. I can only give what I see and read here.

iceblue

IMPO the easiest rout to take would be to street port his motor and put a 75wet shot on the car. That is how I would build a nice little NA.

JoshRX7

iTrader: (5)

Well, I'm not exactly sure what the difference in intake charge temp is between say 10 psi and 15 psi... however, I am not exactly concerned with that since you will be boosting both types of rotors... only one slightly more than the other. The heat I am concerned with is the actual compression of the intake charge at the rotor dish. It is being compressed more tightly causing higher temps... I'll try to find an example of what I'm talking about somewhere in the forum...

Josh