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

Road race turbo

Old 11-19-18, 07:41 AM
  #1  
Full Member
Thread Starter
iTrader: (2)
 
jimmacsrx7's Avatar
 
Join Date: Oct 2005
Location: upton, MA
Posts: 136
Liked 0 Times in 0 Posts
Road race turbo

Hi all, getting back into the track game after a long layoff. I have a dedicated FD track car with a big *** laggy turbo, hits super hard and good for a high speed track like Watkins glen but costs so much time exiting corners or trying to modulate throttle roatating the car. 2011 was last time on track. For the guys who race what is a good fast spooling reliable turbo set up? Iím looking for 400/ 450 rwhp, have big inter cooler, duel oil coolers etc..thanks for any info
Jim
jimmacsrx7 is offline  
Old 11-19-18, 01:11 PM
  #2  
Rotary Enthusiast
 
Join Date: Jan 2005
Location: hsv al
Posts: 828
Liked 7 Times in 6 Posts
To swap to a new EFR turbo it will be $2k+

To swap to a new SXE unit will be close $1k

To swap to a 4.44 or 4.7 ring and pinion so you exit the corners above 4,000 RPM and in boost will only cost you a few hundred.


Do the math and look up the MPH by gear with a 4.44 or 4.77, does that mesh well with your tracks? Are you doing 150 MPH at WGI?
Gilgamesh is offline  
Old 11-19-18, 03:33 PM
  #3  
Lives on the Forum
iTrader: (9)
 
BLUE TII's Avatar
 
Join Date: Mar 2001
Location: CA
Posts: 7,070
Liked 145 Times in 128 Posts
If you have the funds and want to make a solid improvement to your car I would do both the 4.77 rear and the EFR 8374 turbo with re-tune.

On my street/autox/hillclimb/kart track RX-7 I went from T04B 60-1 I had used for 14 years to the exact same size compressor EFR 7670 and the difference in the character of the car/engine/driveability was incredible.

The rotary exhaust seems to make a huge difference on these lightweight exhaust wheel (Titanium Aluminide) EFR turbos.

Like you say, with the "laggy" (full boost by 3,400rpm) 60-1 I had to floor it and ease off the gas just the right amount as the wastegate cracked and/or counter steer just the right amount as the wastegate cracked to keep on line.

With the EFR I could just tip in the throttle progressively and feed the near instant torque in. You know how much torque you are getting as you feed it in so its much easier to judge.

BLUE TII is offline  
The following users liked this post: BLUE TII
jimmacsrx7 (11-19-18)
Old 11-19-18, 06:46 PM
  #4  
Full Member
Thread Starter
iTrader: (2)
 
jimmacsrx7's Avatar
 
Join Date: Oct 2005
Location: upton, MA
Posts: 136
Liked 0 Times in 0 Posts
Thanks guys, I will look into it.. 140 ish into bus stop at the glen, no downforce for the esses. Had a chance to time trial at Monticello before they closed it to average folks and was 150 plus on the long back straight there and it was still pulling..funny how noisy it is at that speed and all the dirt particles etc that get dislodged and float around the car!
jimmacsrx7 is offline  
Old 11-20-18, 11:47 AM
  #5  
RE for life
 
diyman25's Avatar
 
Join Date: May 2002
Location: sca
Posts: 1,173
Likes: 0
Liked 17 Times in 14 Posts
Not thing laggy with big port and stock style twin, even with 4.777 I run at my last endurance race ,
With shorter gear, I am loose some lap time at corner like I can hit rev limit in 3th, now i have to shift to 4th, this loose some time when u still using syncro box
I am in market for single turbo too , I am think EFR too
Attached Thumbnails Road race turbo-a88a2859.jpg  

Last edited by diyman25; 11-20-18 at 11:48 PM.
diyman25 is offline  
Old 11-23-18, 02:13 PM
  #6  
Rotary Enthusiast
iTrader: (5)
 
Join Date: Apr 2006
Location: sb
Posts: 861
Likes: 0
Liked 30 Times in 27 Posts
If you're not chasing giant dyno queen or drag numbers I really don't think an EFR can be beaten if you've got the scratch.
dguy is offline  
Old 11-25-18, 08:02 PM
  #7  
Full Member
iTrader: (5)
 
finger lock's Avatar
 
Join Date: Feb 2009
Location: Bay Area
Posts: 249
Likes: 0
Liked 0 Times in 0 Posts
Hi Jim,

As a comparison to what others have mentioned, I run a Precision 6262 on my track only FD. Prior to the Precision, I was running an Aspec 3574 and the Precision seems very similar. See the attached dyno pull below, I think this was at 18 or 18.5 psi.

Guy


finger lock is offline  
Old 11-26-18, 11:09 PM
  #8  
Senior Member
 
Join Date: Jan 2006
Location: nanaimo
Posts: 422
Likes: 0
Liked 3 Times in 3 Posts
I had good luck with a garret gt35r with a 1.06 housing.
racingdriver is offline  
Old 11-28-18, 10:03 PM
  #9  
Full Member
Thread Starter
iTrader: (2)
 
jimmacsrx7's Avatar
 
Join Date: Oct 2005
Location: upton, MA
Posts: 136
Liked 0 Times in 0 Posts
Originally Posted by finger lock View Post
Hi Jim,

As a comparison to what others have mentioned, I run a Precision 6262 on my track only FD. Prior to the Precision, I was running an Aspec 3574 and the Precision seems very similar. See the attached dyno pull below, I think this was at 18 or 18.5 psi.

Guy


Thanks Guy, good numbers. How is the feel of your car with this turbo? Is the power linear. Not sure if you ever raced a 2 stroke dirt bike but my power is like that..not a lot..then hang on..Iím about 18 psi but I have to stay so busy trying to max out the car itís crazy..I even started messing around with a little left foot braking and feeding some more rpm trying to keep the turbo spooled..if I had a foot camera it would look ridiculous what Iím doing to try and achieve a fast lap.
it is fun driving a high hp car with a short wheelbase and no abs or any other computer aid..when I first started in the mid 90s all the cars were like this but now I feel like a novelty using heel/toe..getting ham fisted on the brakes will cost me a grand in flat spotted tires..
some of the guys with the modern paddle ****,traction control, abs cars would put our cars in the fence trying to run them at the limit in my opinion 🙂
jimmacsrx7 is offline  
Old 11-29-18, 01:56 AM
  #10  
Full Member
iTrader: (5)
 
finger lock's Avatar
 
Join Date: Feb 2009
Location: Bay Area
Posts: 249
Likes: 0
Liked 0 Times in 0 Posts
Jim,

Yes, the response is mostly linear and quite responsive. It makes for a good package.
I would also listen to Racingdriver, he has lots more turbo track time than I do.

Guy
finger lock is offline  
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
diyman25
Race Car Tech
5
12-14-18 03:24 AM
jacobcartmill
Single Turbo RX-7's
4
05-05-13 11:27 PM
7envy
Single Turbo RX-7's
0
09-22-08 11:54 PM
Jack
Single Turbo RX-7's
5
06-09-03 05:29 PM
Carl Byck
Race Car Tech
27
12-05-02 01:35 AM


Thread Tools
Search this Thread
Quick Reply: Road race turbo


Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

© 2019 MH Sub I, LLC dba Internet Brands

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: