thinking of 5.0 swap into my 1st gen, what coil-over rates to use? - RX7Club.com - Mazda RX7 Forum

Go Back  RX7Club.com - Mazda RX7 Forum > Tech and Performance > Race Car Tech
Reload this Page >

thinking of 5.0 swap into my 1st gen, what coil-over rates to use?

Race Car Tech Discuss anything related to road racing and auto X.

thinking of 5.0 swap into my 1st gen, what coil-over rates to use?

Reply

 
 
 
Old 04-25-05, 05:03 PM
  #1  
Rotary Enthusiast
5 Year Member
Thread Starter
iTrader: (3)
 
Join Date: Nov 2004
Location: Parma, Oh
Posts: 1,129
Thanks: 0
Thanked 0 Times in 0 Posts
thinking of 5.0 swap into my 1st gen, what coil-over rates to use?

looking for good suspension ideas for a v8 swap car. not sure if i'm gonna go through with the swap or not, kinday depends on the condition of the engine when i tear it down. if its shot, it might be cheaper to go the v8 route. any ideas on suspension?
wrxracer55 is offline  
Reply With Quote
Old 04-26-05, 05:10 PM
  #2  
Rotary Enthusiast
5 Year Member
Thread Starter
iTrader: (3)
 
Join Date: Nov 2004
Location: Parma, Oh
Posts: 1,129
Thanks: 0
Thanked 0 Times in 0 Posts
anyone? i know the weight gain is not that much, so the rates should not be too different.
wrxracer55 is offline  
Reply With Quote
Old 04-26-05, 09:39 PM
  #3  
Full Member
5 Year Member
 
Join Date: Apr 2005
Location: Arizona
Posts: 118
Thanks: 0
Thanked 0 Times in 0 Posts
well if thats the one being set up for auto-x ur gonna screw ur handling over bad
Tyrael6666 is offline  
Reply With Quote
Old 04-26-05, 09:49 PM
  #4  
GET OFF MY LAWN
10 Year Member
iTrader: (1)
 
jgrewe's Avatar
 
Join Date: Feb 2005
Location: Fla.
Posts: 2,838
Thanks: 0
Thanked 0 Times in 0 Posts
I had a car pass through my stable of rx's that had been set up for a sm.block ford. The guy who originally built it lowered the subframe to fit the engine under the hood. If you got some of G-forces' turn in spacers you could counter act the screwed up geometry a little. He also modified the steering center link to go under the oil pan better. I havn't looked at any other V8 installs, I usually throw rocks at them.

They are fun to drive though.... TORQUE can be addictive
jgrewe is offline  
Reply With Quote
Old 04-26-05, 10:08 PM
  #5  
Gone Race'n
10 Year Member
iTrader: (4)
 
moremazda's Avatar
 
Join Date: Dec 2001
Location: Rockford, IL
Posts: 1,544
Thanks: 0
Thanked 0 Times in 0 Posts
You don't add a whole lot of wheight to the car, but you do shift the weight further forward. So you will basicly have the hadeling caracteristics of a stock Camero. As far as spring rates you might want to start off in the 350ft/125rr and see how it does.

Good luck
Ryan
moremazda is offline  
Reply With Quote
Old 04-27-05, 08:15 AM
  #6  
Rotary Enthusiast
5 Year Member
Thread Starter
iTrader: (3)
 
Join Date: Nov 2004
Location: Parma, Oh
Posts: 1,129
Thanks: 0
Thanked 0 Times in 0 Posts
good point, i didn't think of how much further forward the weight would be shifted. I was gonna build the car for csp, and it all depends on how the stock 12a engine looks on the inside when i tear it down. i don't have a lot of money, so i want something that will be a blast to drive, for as little money as possible. 5.0 engines are really cheap and plentiful used, wheras the 12a parts (housings in good shape) are getting pricey.
wrxracer55 is offline  
Reply With Quote
Old 04-27-05, 09:32 AM
  #7  
Coming to a track near u!
iTrader: (5)
 
RacerJason's Avatar
 
Join Date: Sep 2001
Location: Toronto
Posts: 3,855
Thanked 2 Times in 1 Post
Road racing, AutoX, or Street? If it's AutoX as you say in your Sig. then much heavier springs like 450-500 front and 300-400 rear. Visit http://www.swainracing.com These guys ran a 5.0 RX7 to numerous race wins, email them for more car set up ideas.
RacerJason is offline  
Reply With Quote
Old 04-27-05, 10:26 AM
  #8  
Rotary Enthusiast
5 Year Member
Thread Starter
iTrader: (3)
 
Join Date: Nov 2004
Location: Parma, Oh
Posts: 1,129
Thanks: 0
Thanked 0 Times in 0 Posts
will do, thanks
wrxracer55 is offline  
Reply With Quote
Old 05-01-05, 12:29 PM
  #9  
Senior Member
10 Year Member
 
Join Date: Jan 2003
Location: Springdale,AR
Posts: 552
Thanks: 0
Thanked 0 Times in 0 Posts
V8 Rex

A V-8 RX-7 only fits in one class in SCCA autocrossing, and that is E-Mod where they do quite well. You might get in the Street Mod class for street freaks. Ricers will eat you alive though. Stay in E-Mod. If you try, you can get 50/50 weight pretty easy. Try it/you'll like it.
Dick Elliott is offline  
Reply With Quote
Old 05-01-05, 12:37 PM
  #10  
Senior Member
5 Year Member
iTrader: (4)
 
RotaryAXer's Avatar
 
Join Date: Apr 2004
Location: Dorr, Michigan
Posts: 393
Thanks: 0
Thanked 0 Times in 0 Posts
Originally Posted by Dick Elliott
You might get in the Street Mod class for street freaks. Ricers will eat you alive though. Stay in E-Mod.
Can't go into Street Mod with a Ford V8 in a Mazda. You could use any Mazda motor ever produced and go into SM2 but it has to be a Mazda motor.
RotaryAXer is offline  
Reply With Quote
Old 05-01-05, 06:02 PM
  #11  
Senior Member
10 Year Member
 
Join Date: Jan 2003
Location: Springdale,AR
Posts: 552
Thanks: 0
Thanked 0 Times in 0 Posts
V-8 Rex

Your oh so right! I looked it up in the rule book. E-Mod is ok though. Fun class for cars with more power than stick. DICK.


Originally Posted by RotaryAXer
Can't go into Street Mod with a Ford V8 in a Mazda. You could use any Mazda motor ever produced and go into SM2 but it has to be a Mazda motor.
Dick Elliott is offline  
Reply With Quote
Old 05-01-05, 06:07 PM
  #12  
Rotary Enthusiast
5 Year Member
Thread Starter
iTrader: (3)
 
Join Date: Nov 2004
Location: Parma, Oh
Posts: 1,129
Thanks: 0
Thanked 0 Times in 0 Posts
thanks for the advice. i'm not sure what way i will go. good to know though.
wrxracer55 is offline  
Reply With Quote
Old 10-26-05, 12:53 PM
  #13  
Rotary Enthusiast
5 Year Member
Thread Starter
iTrader: (3)
 
Join Date: Nov 2004
Location: Parma, Oh
Posts: 1,129
Thanks: 0
Thanked 0 Times in 0 Posts
Well, I'm bringing this back up, as I am pretty sure the 12a in my car needs replaced. I got a line on a good 302 for a good price, so I think I'm gonna go that route. The car will be setup for EM. I am going to run coilovers on all 4 corners, and was thinking of going with the same rates that I was gonna use when setting the car up for CSP (400/200). do these sound like a good place to start?
wrxracer55 is offline  
Reply With Quote
Old 10-26-05, 01:33 PM
  #14  
Senior Member
5 Year Member
iTrader: (4)
 
RotaryAXer's Avatar
 
Join Date: Apr 2004
Location: Dorr, Michigan
Posts: 393
Thanks: 0
Thanked 0 Times in 0 Posts
When you say coilovers on all 4 corners what do you mean?

Are you planning on making something to adapt a "coilover" in the rear. Will you have a threaded shock body with the spring around it?

Did you really just mean that you would have adjustable spring perches at the factory spring locations?

Will you be using the stock axle, or modifying a Ford 8" or something?

Until you have a clear picture of how the spring is going to be attached and any associated motion ratio or spring angles are accounted for you can't state what spring rate will work.

If you are using all stock mounting then 400/200 sounds reasonable.
RotaryAXer is offline  
Reply With Quote
Old 10-26-05, 04:30 PM
  #15  
Rotary Enthusiast
5 Year Member
Thread Starter
iTrader: (3)
 
Join Date: Nov 2004
Location: Parma, Oh
Posts: 1,129
Thanks: 0
Thanked 0 Times in 0 Posts
Yes, ground control or ISC perches. Sorry for the confusion. Stock rear end for now (with discs and lsd). If it doesn't hold up, then I will be looking into a 8.8 swap.
wrxracer55 is offline  
Reply With Quote
Old 10-26-05, 06:04 PM
  #16  
moon ******
5 Year Member
 
Nihilanthic's Avatar
 
Join Date: May 2005
Location: Jacksonville, Florida
Posts: 1,308
Thanks: 0
Thanked 0 Times in 0 Posts
You guys are total ******* morons.

The weight change is usually NEGLIGEABLE, if that. It might gain some weight, but its for the most part centered. People have come out TAIL heavy with this swap because.... guess what? The engines behind the front wheels, and so is that transmission. Well, what I follow are FCs and FDs, I really doubt the FB is *THAT* different. I thought all RX-7s followed the same sort of formula - stiff chassis, light weight, front wheels ahead of the engine...

The 302 is not a heavy engine at all, btw. Its roughly the same as a LS1 in terms of weight, and we all know how they somehow have the magical LS faries shove the nose around to prevent understeer when its put in FCs and FDs

But anyway, MORE than likely, with just regular FB coilovers, you would do fine. Unless you did some custom install and have the engine real far forward, its going to sit back against the firewall and handle just fine.

But anyway, before you spout **** like youre gonna make it handle like a camaro, why not WEIGH THE ******* CAR? Jesus christ.

Also, if you lower the rack and change geometry, you could go get a tierod kit and fix it. But then again you dont need to lower the subframe unless you wanna use a stock hood and a higher intake or the 302 has distributer clearance issues. Again, Im more into FCs than FBs.

And uh, just as far as FBs go in general, you might wanna switch from the watts link to a properly sized/placed panhard bar and lower the rollcenter a little. And yes, you can switch to a different rear end (ford 8" or 9") if you want. 302s can put out insane power (Zuxbeinyu is putting basically 420/420 @ the wheels out of a NA 302)without needing high revs or boost.

But yeah, get yourselves to...
http://www.torquecentral.com/forumdisplay.php?f=11 and https://www.rx7club.com/forum/forumdisplay.php?f=118

And for gods ******* sake, the 'weight' and 'balance' issues with the swap only exist in your ****** heads. Its been PROVN, OVER AND OVER AND OVER AND OVER, THAT IT DOESNT HURT THE HANDLING! Now, if you go do something insane like put a 454 in it, then yes you will impact the handling.

Then again, that would be a great highway killer, and its hard to not intimidate someone with the engine and heads sticking out of the giant hole in the hood to accomidate the big block v8
Nihilanthic is offline  
Reply With Quote
Old 10-26-05, 07:35 PM
  #17  
6 Speed FC
10 Year Member
iTrader: (2)
 
Brismo7's Avatar
 
Join Date: Aug 2005
Location: Orange, CA
Posts: 2,259
Thanks: 0
Thanked 0 Times in 0 Posts
yeah right, V8's will ruin any cars handling. thats why mustangs and camaros handle so bad.


Brismo7
Brismo7 is offline  
Reply With Quote
Old 10-26-05, 08:43 PM
  #18  
Senior Member
5 Year Member
iTrader: (4)
 
RotaryAXer's Avatar
 
Join Date: Apr 2004
Location: Dorr, Michigan
Posts: 393
Thanks: 0
Thanked 0 Times in 0 Posts
Nihilanthic,

A little language now and again is fine but your post is just out of control.

This is a technical forum not the lounge.

Other than that I found your post to be well thought out and somewhat informative. Though I don't know that your post was any more fact based than any of the others. I need to see corner weights before and after a swap to really believe there is no overall weight gain or any weight distribution difference. It may be entirely true, I just don't think I have ever seen corner weights of an equally equipped FB before and after the swap.
RotaryAXer is offline  
Reply With Quote
Old 10-26-05, 09:17 PM
  #19  
moon ******
5 Year Member
 
Nihilanthic's Avatar
 
Join Date: May 2005
Location: Jacksonville, Florida
Posts: 1,308
Thanks: 0
Thanked 0 Times in 0 Posts
I am sorry, but sometimes Its hard to tolerate it when people spew the same nonsense when its been disproven, over, and over, and over again. If this is the technical forum they should know better than that stereotyped crap by now!

But anyway, yeah. Generally weight distro stays about the same, if not a little better because of a heavier transmission and the engine being mounted far back, and because you get to lose the oil cooler and IC (if its a turbo). As far as gain goes, it can be nil, to negative, to 120 or so. But because its in the middle its not that much of a problem - Id compare it to a full turbo kit with the assorted IC/oil cooler/manifold and other stuff - just behind the struts!

Now, as far as going full race, if youre doing a full strip ANYWAY, I seriously doubt youre going to be caring about adding some driveline weight when youre ditching everything else and caging it. If you also really want to keep it weightd out, just put in a ford 9" in the rear, but that might make it REAR heavy.
Nihilanthic is offline  
Reply With Quote
Old 10-27-05, 01:23 AM
  #20  
Senior Member
10 Year Member
 
Boswoj's Avatar
 
Join Date: Nov 2004
Location: Pacific Northwest
Posts: 298
Thanks: 0
Thanked 0 Times in 0 Posts
Check out Granny's Speed Shop in Concrete, WA. They have some great info for Rx-7 swaps. If done correctly, it doesn't seem to increase weight that much and balance isn't horribly affected. I wouldn't give up my rotary powered EP car, but a 1st gen set up for endurance racing would give you that out of the corner grunt and straightaway passing that helps save the car over long runs. It's great to have a car that can pass in the corners but in endurance racing that's where all the sheetmetal damage occurs. I know it's the sissy way - but horsepower wins races! Those Miata drivers grin when they stuff it under you on corner entry, but you can't see those grins quite as well when you are looking at them 20 car lengths back in the mirror at the end of the next straight.
Boswoj is offline  
Reply With Quote
Old 10-27-05, 01:27 PM
  #21  
6 Speed FC
10 Year Member
iTrader: (2)
 
Brismo7's Avatar
 
Join Date: Aug 2005
Location: Orange, CA
Posts: 2,259
Thanks: 0
Thanked 0 Times in 0 Posts
Baswoj:
Those Miata drivers grin when they stuff it under you on corner entry, but you can't see those grins quite as well when you are looking at them 20 car lengths back in the mirror at the end of the next straight.

lol.
Brismo7 is offline  
Reply With Quote
Old 10-27-05, 01:53 PM
  #22  
Rotary Enthusiast
5 Year Member
Thread Starter
iTrader: (3)
 
Join Date: Nov 2004
Location: Parma, Oh
Posts: 1,129
Thanks: 0
Thanked 0 Times in 0 Posts
Thats why I want the V8. I love the feel of torque. I figure if I can get the car to 2,000 lbs, with 350-400 hp, it should be a lot of fun (at least those are my goals). The 12a that is in it is shot, and it will be cheaper to convert it in the long run. If the 12a was still good, I wouldn't do the swap, but it has 170,000 miles on it, and is very tired. Shelby is my idol, and since I can't afford a Cobra now, I'm gonna make my own. ; )
wrxracer55 is offline  
Reply With Quote
Old 11-07-18, 10:38 AM
  #23  
Senior Member
 
Join Date: Jun 2013
Location: FL
Posts: 270
Thanked 0 Times in 0 Posts
wrong thread

Last edited by ATC529R; 11-07-18 at 10:42 AM. Reason: wrong thread
ATC529R is offline  
Reply With Quote
 
 
 
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
The Shaolin
2nd Generation Specific (1986-1992)
9
09-14-15 08:50 PM
craaaazzy
Website-related Comments, Suggestions and Issues
3
08-21-15 03:00 PM
Marty RE
New Member RX-7 Technical
0
08-13-15 12:19 PM
RCCAZ 1
1st Generation Specific (1979-1985)
5
08-11-15 08:05 PM


Thread Tools
Search this Thread
Quick Reply: thinking of 5.0 swap into my 1st gen, what coil-over rates to use?


Contact Us Archive Advertising Cookie Policy Privacy Statement Terms of Service

We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.
 
  • Ask a Question
    Get answers from community experts
Question Title:
Description:
Your question will be posted in: