agent712

Hi, this is Nick's brother Chuck. Gotta few questions regarding my first thoughts on what I want to do to his car to give it some more punch...

1. Cold air intake. Does anyone make one? If so, who has the best bang for the buck? I was looking at the stock air box/silencer setup and that thing has GOT to go

2. Exhaust. Is a cat back worth some decent power on these cars? If so, which brand do you recomend?

3. Boost controller. How much boost do these put out stock, and how much can they handle stock?

4. Rev limiter. What's the highest these motors can rev stock, and does anyone make a programmer for the computer to bump up the rev limiter?

5. Stall converter. Does anyone make a good stock upgrade. It's very obvious w/ the automatic these cars suffer for bottom end power...


That's about all I can think of for decent bolt ons. So please comment if you could since I am not familiar w/ what is available for the RX7's. I'm a Chevy boy and kind of stick to my V8's, but respect all cars that make good power, and this car does. I just want to help my brother get it running to where he can keep up with the pack. I've got a 97 SS w/ a very stout 383 that should make over 500 hp in the works, and my best friend has a twin turbo'd 300ZX producing around close to 500 hp.


Thanks for the help
Chuck
www.barncandles.com/camaro/Chucks.htm

jimlab

Who is Nick?

The 3rd gen. has been around for 10+ years, everyone and their brother has made a cold air intake for it. Pick one with a box, otherwise you're just pulling in hot engine bay air. N-Tech, M2 Performance, Crooked Willow, take your pick. Try the search function, there's plenty of info.

No, no cat-back by itself is really worth much on any car in my experience. On average, maybe ~10 horsepower, tops. You'd be better off getting a downpipe and getting the heat of the pre-cat out of the engine bay, if possible. Change the cat-back if you want to change the sound of the exhaust. Until you can safely run more boost, you're not going to make a lot more power with exhaust or intake mods.

For information on first mods, here's a good place to start...

https://www.rx7club.com/forum/showth...threadid=28002

~10 psi, and ~10 psi. Get a boost gauge and find out if the car is making proper boost. 10-8-10 is pretty much standard "healthy" boost response, give or take, with the 8 psi coming at the transition to both turbos at around 4,500 rpm.

To safely run more boost, you'll need fuel mods, at least a downpipe, and a bigger intercooler, at the very least. Anything you can do to get heat out of the engine bay is a plus, anything you can do to upgrade the fuel system is even better.

Check the tachometer. Where the red starts is the redline for your model, and you don't raise the redline on these cars like you would with a Camaro with heads and a bigger cam.

They'll still suffer for bottom end power, but at least with a stall converter you'll be able to launch higher in the power zone. Talk to Level 10 or Pro Torque. I haven't paid much attention to the automatics, so I don't know if any of the traditional RX-7 vendors carry upgraded torque converters, but you can check there too. Pettit, Rotary Performance, SR Motorsports, etc., take your pick.

Solid roller cam, I presume? I just broke the record for NA LT1 horsepower by 40+ horsepower (640.8 on base maps), and we're not done tuning it yet. It's going in my '95 RX-7.

Smilez

Jim, You just wanted to show off your engine

jimlab

Yep.

agent712

Looks like something Mark Montalvo built. Very nice. I'm putting together the following....
Block, stock iron w/ splayed center mains, deck height of 9.015
Eagle 4340 crank, 3.75 stroke, lightened rod jourals
Eagle 4340 H beam 6" rods
Ross forged aluminum pistons w/ a 11 cc dome producing around 13:1 compression w/ a 64cc head depending on what size head gasket we go with
Cam Motion custom ground solid roller cam, .684/.671 lift-261/261 duration @ .05, 112 lsa, 108 installed
Jesel Sportsman shaft mount rocker arms
K Motion K800 springs
CNC of Florida heads that flow a max of 280 cfm @ .600 lift
Hooker Long tube headers
Custom true dual 3" exhaust w/ build in baffles eliminating the need for mufflers
Dual electric QTP cutouts
Holley dual 58mm (1100 cfm) throttle body
T56 6 speed
Mcleod Street Twin clutch
Global West Traclink torque arm
Global West lower control arms and panhard rod w/ spherical bushings
South Side Machine subframe connectors
BMR Strut tower brace
And a custom 8 point NHRA legal roll bar

The heads are temporary, I just got a good deal on them so I threw them on. I plan to go w/ a set of AFR 210's, or a set of 18 degree's from Brodix. We'll see how it does for now...

Thanks for the help and the link!


Chuck

agent712

BTW. The car already has a larger downpipe.


Later
Chuck

jimlab

Yep.

Sounds like you've got some good stuff going into your engine. I went a little overboard on cutting weight and spent the money for a custom Crower billet ultralight crank (37.8 lbs.) and custom Maxi-light rods (505 g) with a stroker profile, and spent it on a few other things, like Titanium valves in the AFR 215cc RR heads, and the Hogan Racing intake, obviously. 12.2:1 compression, and a Cam Motion solid roller with similar specs to yours.

We got flow in the 340 cfm range from the AFRs with 2.10/1.65 valves. If you go bigger in the future, they're a very good option. No one had an 18 degree head that could easily be converted to reverse coolant flow, so AFR cast the 215s for us. Mark took a set and I got a set. Of course you have to run perimiter bolt valve covers, but that's a small consideration for ~340 cfm on the intake.

agent712

Yeah, I may go with the 215's, just don't know how well they'll do on the street. I'll be curious to see what kind of power you make down low when you get that running...
BTW. My cam's duration has 268/261 duration not 261/261.

Later
Chuck
www.barncandles.com/camaro/Chucks.htm

Want2race

Jims motor is artwork! I wouldnt use it.. just keep it in a closet or something!!

agent712

What are the benifits between porting the stock air box and getting a complete aftermarket cold air intake? Or is it just the price? And what brand CAI does everyone like best that flows good and keeps the hot air out? What kind of gains are seen w/ a CAI?

Thanks
Chuck

7-sins

Jims motor is a piece of work. Eventhough it is going in a 7.

Want2race

your right.. the motor is tooo good to go in an RX-7!!

Jim .. put it in something that deserves it!

agent712

Like?



Chuck
www.barncandles.com/camaro/Chucks.htm

Quik 93 FD

yeah, uhh, jim, if ya got any spare rotary motors lying around, hook a brother up. I mean with all that V8 power, who needs a little 1.3L sitting around in the garage?? HELL, ill even pick it up from you....

jimlab

I got rid of my 20B in '99 and I sold my last 13B-REW (below) unused in '98, sorry.