Insert BS here A place to discuss anything you want!

Black Thunder Down Under

Thread Tools
 
Search this Thread
 
Old 06-03-2003 | 10:17 PM
  #1  
Munch,Munch pistons for lunch's Avatar
Thread Starter
Senior Member
 
Joined: Apr 2003
Posts: 181
From: South Coast, NSW Australia
Default

There's nothing like watching a Rotary launch at 9,000rpm off the line….



Chris Anderson's Series 4 RX7 is taking challengers in the U.S rounds of the Pro Import series. Late last year Chris ran 9.20 at 150mph at the Moroso IDRC Nationals. Making the time even more impressive is the fact that the car is still un-tubbed (26x10 inch Mickey Thompson ET slicks) and still weighs 2600lbs.



Under the bonnet, the 13B Rotary engine has received some serious modifications. Unlike in Australia where most people opt for a large turbo type extend port, Chris' RX7 utilizes a secondary 'Bridge Port'. For those that aren't quite familiar with Rotary porting, this is where a second hole or port is cut into the plate above the standard one which is also enlarged. The common myth is that by running such a large port, there will be too much overlap and your boost will go straight out the exhaust. Well Chris says that when done correctly, the bridge port works well. Actually just about all the top runners there are either using a BP or PP! The secret is in the amount of overlap to make it work effectively. The rest of the engine is fairly standard. Now running a 13BRE intake manifold from the Cosmo, 9.0:1 rotors' and Mazda 3mm Apex seals. For extra strength, the housings have had extra dowelling performed.



Rotary's love boost and Chris has amended this by installing a large Garrett T-72 turbocharger with a P-trim wheel and a HKS waste-gate. Fuel delivery is taken care of by a Haltech ECU, .Weldon 2035 fuel pump, 2 x 680cc primary injectors and 2 x 1600cc secondary injectors, while an MSD controls the ignition. On 32psi the car has made 608rwhp. A direct port Nitros system has also been trialed and on 35psi, the car turned the rollers to a tune of 689rwhp. The 9.20 pass was also only on 32psi. You don't produce numbers like that on unleaded fuel, with VP-C16 fuel being the chosen juice.



Obviously with so much power and a sticky track, drive-line breakage's can occur on a frequent basis. To overcome this the RX7 is fitted with a Richmond 5-speed Transmission which is a pro-shifted version. It basically means he still has to use the clutch to shift. This is taken care of by a Tilton twin plate unit and further down the line is an Mopar differential with mega strong 35 spline Moser axels. Chirs is still using standard front brakes to pull up from such insane speeds. Chris says "The parachute is not mounted on the car as yet because I'm building a wing for the rear. Trust me I've been warned numerous times about the chute from the track officials".



Having to compete against 1500lb Honda's can become quite frustrating so Chris is currently in the process of removing as much weight as possible by adding some fiberglass body parts, doors, rear hatch etc. The aim is for 2000lb's, and to be competitive in this weight class really does call for some chassis modifications with either mini tubs or just go all the way and run a half chassis! Future engine modifications are mainly centered around converting to an Alcohol/Methanol fuel.



In just the last month Ari Yallon of Rotary Performance in his un-tubbed S6 RX7 has run 9.116 at 149.52mph, while in Puerto Rico, Toledo Racing's un-tubbed Series 5 RX7 ran 8.90 at 152mph, so as you can see, the competition is certainly fierce! Chris is keen however to give just one more try at the World Import Challenge in March to break into the 8 second time zone with a uni-body un-tubbed car before making the changes listed above.



By Muzza & Mates
Old 06-03-2003 | 10:24 PM
  #2  
Apex13B's Avatar
Senior Member
 
Joined: Nov 2002
Posts: 1,679
From: Colorado Springs
Default

i still dont get why people try to make a production car that fast, and drag racing



anything under 13 secs is impressive to watch though
Old 06-03-2003 | 10:28 PM
  #3  
vspecpgt's Avatar
Senior Member
 
Joined: Jan 2003
Posts: 354
From: i move around alot i'm 98 years old
Default

did it say that rotaries love boost?
Old 06-04-2003 | 12:04 AM
  #4  
SPEED_NYC's Avatar
Senior Member
 
Joined: Sep 2002
Posts: 1,089
Default

thats a very old article, and the chris anderson they are talking about is crispeed from the 'other forum' his car has already been converted to methanol, but he is thinking of scrapping the project alltogether and building a FD.....
Old 06-04-2003 | 12:07 AM
  #5  
Geoffman72's Avatar
Senior Member
 
Joined: Nov 2001
Posts: 1,234
From: Rochester, NY
Default

Originally Posted by vspecpgt' date='Jun 3 2003, 09:28 PM
did it say that rotaries love boost?
And you disagree....?
Old 06-04-2003 | 12:12 AM
  #6  
TYSON's Avatar
Senior Member
 
Joined: Jan 2003
Posts: 2,871
From: London, Ontario
Default

I seem to have missed hearing about RP running 9.116. I thought they were still around 9.6?
Old 06-04-2003 | 12:49 AM
  #7  
SPEED_NYC's Avatar
Senior Member
 
Joined: Sep 2002
Posts: 1,089
Default

RP ran 9.2 or something with a g force tranny



as far as i know they are still at about 9.6 with the mazda tranny
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
wankelTII
1st Generation Specific
10
04-16-2007 08:03 AM
onekwik7
RX-7 & RX-8 For Sale
1
04-04-2006 08:12 PM
liquid_vanity
Events
0
04-27-2005 03:22 PM
venomrx7
Insert BS here
3
01-08-2005 02:15 AM
Munch,Munch pistons for lunch
Insert BS here
1
06-03-2003 10:13 PM

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 



All times are GMT -5. The time now is 03:56 PM.