frankis72

Hey everyone,
I did a quick search but didn't really find an answer. If I've missed it, I'm sorry.

But anywho, I wanted to know if its worth it to put a second gen rx7 turbo into my 04 AT rx8?

I found two great prices (I think) on craigslist. Here are the two craigslist listings I'm looking at

http://chicago.craigslist.org/nwc/pts/1258190332.html

http://chicago.craigslist.org/nwc/pts/1258210314.html

I'm not really an expert in performance modifications, im more of an electric and audio guy. But I tend to figure out how things work after I spend some time researching it. I know its technically possible to put that turbo in, I just don't know what other parts I'll need to buy, and how much more its going to cost me. Is it even worth it?

Thanks alot!

expo1

There isn't a good reason to put something not designed for the RX-8 on it when there are systems out there that are a better fit. Other than the turbo itself you would have to rig all the other parts. There are some major differences between the two motors

frankis72

Oh i fully understand that. I would much prefer a Greddy Turbo...buuut I don't really have $3k laying around. I'm looking more around $300. lol, I know, I'm dreaming. I just kinda saw those adds, and started thinking. Couldn't live with myself if I knew I had an opportunity for a turbo at a low price like that, and just passed it by without checkin on it.

Ross_Dawg

iTrader: (2)

Don't do it;

but who am I to stop from you from making a custom turbo build... If you can build a turbo kit for $300 you must be Jesus

Psychofox

all you have is 300 and you want to turbo your rx8.

frankis72

lol, i told ya I was dreaming. Just thought worth to ask...

but while on the subject. What do you guys think is the best way to put my $300 to good use

Ross_Dawg

iTrader: (2)

afe ss

frankis72

on an AT?

Ross_Dawg

iTrader: (2)

my bad, re-read the op. I would get an aem intake or save for an AP

G3tR3DDY2GR3DDY

iTrader: (8)

300 towards some clear corners, nice brakes, and a day at the track

05rx8mazda

iTrader: (4)

300 bucks on gas bro!!! this car guzzles it like it were a drunk haha

RoTaRyRx-8

^^ im used to my gas eater, i just fill up $20 a week and its good for me

Check out the for sale section their is some nice parts for cheaper

04RX8man

Midpipe....

TheWulf

iTrader: (4)

I say sway bars. Best $300 I spent on my car so far. (Progress tech)

Spinning Sushi

iTrader: (21)

Get the turbos. Just stick one right next to your windshield fluid washer tank, and one right next to the air pump without anything holding it down. That way, when you're driving around and you beat a Civic, tell them that you have twin turbos under the hood.

Show it off at meets when people doubt that you have twin turbos in your car.

Bring it to SevenStock and win 1st place.

Trust me, it's worth the investment.

Mawnee

When putting a turbo on your car, the actual turbo is only a fraction of the total cost. Have a look at my custom turbo build for an idea of all the other stuff you have to buy. And keep in mind my setup assumes you can weld up your own manifold and downpipe

https://www.rx8club.com/series-i-major-horsepower-upgrades-93/mawnees-custom-turbo-build-173808/

04RX8man

I agree with renesis..twin turbos....or better yet a turbo whistler!...that way it SOUNDS like u are T/C

frankis72

doesnt matter now....its totaled...

czar

iTrader: (3)

that was fast

frankis72

i slipped off the road, over a big curb, and hit a tree. it looked pretty gone to me, both front wheels broke off, hood and bumper and driver side fender completely destroyed. but i just got a call from insurance, and apparently there gonna fix it! woo!. but now im thinkin maybe i should stay away from turbos in general..haha

rotarygod

The 2nd gen turbo is a huge exhaust restriction. It's not even easy to spin by hand. It's got some pretty good lag for it's size too. Above about 9 psi it turns into a heat gun. Peak system efficiency on it is only 49%. The '87-'88 TII's had 182 rwhp and 183 ft lbs of torque. The turbos fell off in power after about 6000 rpm and there was no point in shifting higher than 6500 rpm. This was all from about 7 lbs of boost. Keep in mind your engine makes that in horsepower with no boost! Then '89-'91 TII's had slightly higher compression and a slight revision on the turbo exhaust side but with the same compressor. It had 200 hp and about that in torque. Boost was also upped to 8.5 psi. Because of the restrictive nature of those turbos, those cars got horrendous gas mileage. The 3rd gen RX-7 had much better mileage. It's turbos sucked too but there were 2 of them and they spun easily.

The most I've ever seen on a TII turbocharger was on a built engine pulling out all the stops. It did right at about 280 rwhp and that was running on the ragged edge. They aren't too bad if you want about 240-245 reliably with a free flowing exhaust but after that they really start to heat things up.

As a comparison, back in the late 80's there was a supercharger kit for the n/a 2nd gens. It was packaged by a man/company named Nelson and used a Paxton supercharger. I forget the exact model. SN92 or something like that. It had straight cut turbine blades and was inefficient by modern standards. It was also a friction drive. Instead of gears or belts internally, it used different sized ball bearings that were packed in there so tightly against each other that the friction between them spun the compressor when the pulley was turned. They were even hard to turn by hand. Basically we have a supercharger that was mechanically inefficient and thermally inefficient. Lose-lose. When installed on those high compression engines, they also used no intercoolers. On top of that they weren't tuned! You backed timing down by 5 degrees on the crank angle sensor which means 5 degrees everywhere regardless of load or rpm. All they did was use a rising rate fuel pressure regulator. Scary!

Now even with the above supercharger inefficiencies, no intercooling, no tuning which is surely leaving power on the ground, and a peak of about 7 psi, they did right around 215 hp at the wheels. That may not sound very good but it does reinforce the gross inefficiency of the stock TII turbo that was tuned, and was intercooled.

What you'd notice on an RX-8 is that your off boost response would be terrible and your gas mileage would get noticaly worse even when staying out of boost. When boost does kick in, you'll get some decent midrange out of it but you'll really start to lose power over about 6000 rpm or so. With the way the Renesis breathes, if you kept revving it up to redline you may actually get less than stock hp levels up there with nothing more than a glowing turbo and hot intake temps to show for it.

To me it's a no brainer. Then again I used to have a Turbo 2nd gen but now drive an n/a and prefer it.

Since you just wrecked it, it just means that the TII turbo won't have a chance to kill your engine!

dondo

iTrader: (7)

agreed.