i was just curious, i know theres prolly alot of threads on here about this, but if someone was able to piece together a turbo kit and everything and boost their na engine, what would be the downfalls etc? i know alot of people on here would say "just go get a tII swap, it will be cheaper, etc, etc" but how many people have boosted their na engine, and can you use the turbo 2 manifold, etc?

 

Search, search, search. I think it's even in the FAQ.

 

here is a pretty good visual of what needs to be done
http://aaroncake.net/RX-7/naturbo.htm

 

ahhhh

 

IF you use a series four turbo, make sure you make the twin scroll functional or you'll lose low down power. Slower to boost is what I just said.

 

having 3 rx7's in the past, and being on the forums, figure you would have the basic idea's down?

 

He's a noob which means he knows nothing except how to hit "new thread" and it shows.

 

word...ive owned 3 na fc's, never really wanted to boost one, i was really wanting to see how many people on here actually had a na 13b that was turbo...i really didnt need you to try to be a dick to feel better about urself. thanks anyways, i lookd in the faq like u had said.

 

My friend here in Orlando has a S4 na that someone just slapped a S5 turbo and ghetto intercooler onto. No changed harness or wires. Still N/A computer. Just a safc to add some fuel up top. It doesn't seem to have a problem spinning till 3rd gear. Never knocked at all. Too bad it dropped a side seal.

Long story short, dont boost na. Get the right stuff.

 

Boost it but do it right.

 

I have run the numbers many times on producing an NA turbo kit and every time, come up with the same result. To make a reliable, high quality, totally bolt on NA turbo kit that would put down 300HP, I would have to charge $4500 US for at least the first 10, after which the price would come down a bit. Problem is, no one would be willing to spend that much money.

Which I find surprising, because a turbo "kit" for a TII (which consists really of only a turbo, manifold, wastegate, downpipe, oil/water plumbing and other misc items) using the same turbo I was looking at costs $3999, and you still have to buy management, intercooler, etc. But the fact is that many 2nd gen owners are...cheap. They either can't afford or don't want to pay. So it's flat out not worth the significant investment in time and money it would take to bring a kit to the market.

 

why make a turbo kit for the t2's when himni racing makes their own?

 

There are so many kits for the TII from various vendors that it wouldn't make much sense to make one. I was illustrating that an NA-turbo kit seems to have a high cost, until you consider it would be complete while the TII kits which seem to be cheaper, just include the basic turbo stuff.

 

Not a single one of you has answered his questions yet. He isn't asking how much people would be willing to pay for a kit or how much one would cost to make. He basically asked these 3 questions.

1: What would be the downfalls of boosting an n/a engine?

2: How many people have boosted their n/a engines?

3: Can you use the Turbo II manifold(s)?

 

plenty of people do it. the limiting factor is fabrication skills and electronic skill to get the thing to be a properly boosted car.

you can use t2 manifolds, just needs to be reworked a lil bit on the intake manifold. nothing too major i dont think.

 

just buy a rotary that is turbo already. i promise you will have less trouble.

 

I doubt that. It's just not that easy. I flew 1300 miles across the country to buy a 90 GXL because it was bone stock. I have yet to see a TII for sale that I'd actually pay for. If one could be found for a good price that was bone stock then I'd go for it but most aren't and most TII owners have abused their cars and have poorly done mods. Yes I said it. Most of you people have RX-7's that aren't worth a plug nickel due to what has been done to them! I actually did find an 87 TII that was bone stock in great shape sitting in San Antonio. That's only a bit over 3 hours from here. They wanted $8500 for it. I paid $2700 for a good condition bone stock S5 n/a. For the price difference there was no way I was going to buy an S4 TII. It wasn't worth it. A nice S5 TII I'd have thought about but that's still pretty steep.

I'm all for finding a nice RX-7 first and foremost regardless of whether it's a turbo or not. If one can be found then great. Otherwise get a nice n/a and do what you want with it.

To answer his questions:

1: The downfalls are the same with any other engine. Money being the first thing but the more you can do yourself the cheaper it gets. My advice is take your time and do it right once rather than getting done in a hurry and doing it again. Do some research on the components you'll need but it is more than just the turbo and intercooler. Look into new fuel injectors, fuel pump, engine management, etc to start.

You'll definitely want to run higher octane fuel such as Supreme. Good old 87 isn't going to cut it anymore so plan on it costing more to fill up.

You are going to hurt your gas mileage a bit. No way around that.

You may kill your clutch or transmission faster. That depends on how you treat it but that's a possibility.

If all goes well you may have a smile on your face that you can't seem to get rid of.

2: How many people isn't really relevant as many have tried, some have done it, and few have done it well. It all goes back to talent, patience, and budget. Yes it has been done successfully though and Aaron Cake is a good example. He also has a very realistic idea of what things cost and how difficult it is. He has an entire thread on his conversion and then subsequent mods since then so go search for those.

3: You "can" use the TII manifolds if you wish. Both intake and turbo. However if you want to use only the exhaust manifold for the turbo, you'll have to space it out as Aaron did. If you want to use both the intake and exhaust manifolds, you don't need to space it anymore but you have to modify the lower intake manifold so the secondary runners like up. You will also lose the 6 port system but you may anyways. A nice thing about using both TII intake and exhaust systems is that they can be completely swapped over from a TII and transplanted with little fabrication work. Even a TII downpipe would work. From a simplicity standpoint this would be easiest. It's definitely easier than using the na intake manifolds with a TII turbo. It's up to you. Either will work.

Consider a few things though such as oil metering and throttle cable length. These may or may not be affected depending on which route you choose. I would consider it easiest to piece together TII parts off of ebay and the internet. Look for TII intake manifolds, turbo, downpipe, injectors, fuel pump, ecu, hood, and intercooler. Of course you could always use aftermarket parts for any of these such as a front mount intercooler instead but for ease of install this would be quickest and least painful. It would also be the cheapest.

A bad thing about thinking this is still a direct swap though is that you still won't have an oil or coolant return from the turbo. The coolant isn't really a problem as you'll only need to remove a freeze plug from a rotor housing but the oil return is an issue. You'll need to think something up here or go to all the trouble of using a TII front cover too. Aaron did have an alternative way to send return oil back on his.

Hopefully this is some decent starting info to help you out. Even easy, it's not a weekend swapout. You could at least keep the stock wiring harness and use a TII ecu and map sensor but even then there are 2 wires that are different that need to be dealt with.

It's possible and it doesn't have to be too expensive. It can definitely be worthwhile though and not necessarily more costly than finding a TII. You just have to do your homework. We've got lots of info in the archives so start digging and make a list of what it will take and find out costs. Then determine whether or not you can justify it.

 

ill answer the questions then! i used to run a 6 port turbo for a couple years.

1: What would be the downfalls of boosting an n/a engine?
higher compression means you must be more careful when tuning.

2: How many people have boosted their n/a engines?
well i for 1 have,
3: Can you use the Turbo II manifold(s)?
yes, thats what i did actually
my setup
s4 turbo II intake manifolds port matched to a 6 port block. t2 fuel rails, boost sensor, afm, throttle cable , 550 primarys, 720 secondaries, rtek 1.7, safc, walbro 255. then i used na wiring harness.i taped the oil pan for an oil return,a nd then i used the oil pressure gauge port as an oil feed( you can buy a T if u want to retain the stock gauge) ohh and for water i had a hose going in before the heater core and water return after the heater core.

so basicly just like a t2 setup but with a 6 port block, most peopel probably wouldnt notice the diff.

 

Everyone seems to have missed the part so far where you have to tap the rear iron for a oil feed. People seem to think you can just do this with the motor in the car. I would NOT recommend this. Metal shavings in the oil is a BIG no no.

Your not going to pull the oil volume you need off a switch location (oil pres. gauge location) and blow up the turbo. For coolant return, you could just tap the filler neck of the water pump.

 

You just need to find 10 guys like me that have already thrown $20,000 at their stupid NA FC and are willing to throw 3k more at it. I'm even looking at supercharging but I'd rather go turbo.

 

Actually no one missed it. This isn't a tutorial. He needs to do his homework. Oil isn't fed from the rear housing anyways. On the TII it's on the front housing. You actually don't need a whole lot of flow to the turbo. Much less than people think you do. An oil filter adapter would be a great place to pull oil and it's easy. Racing Beat even sells one that just screws on between the filter and the housing. Simple.

 

My bad. It's early and I just woke up. I mean't the front iron. I've heard the oil filter pedestals are famous for leaking?

And I guess your right. If we tell him how to do everything, when something breaks, he wont even know where to start looking to fix it...

 

Early at 3 pm!!!! Wow.

 

Working graveyard shifts rapes my sleep schedule.

 

Yeah and if its an S5 (not sure about S4s) you don't need to tap anything for the coolant lines, steal the ones for the BAC. Its a very easy conversion thats a bit overhyped on this forum.

The only downside is engine management. You can either run the stock TII ECU and sensors and risk the extra timing/run low boost or go full standalone if you have the money. So no low-budget options for engine management, besides an SAFC/RTEK/FCD setup which would be wasted money. You can go RTEK if you have an S4 setup though if you're aiming for mid 300s max.