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

IT7 Car Feels Slow...

Old 11-15-12, 10:54 PM
  #1  
Racing is life.
5 Year Member
Thread Starter
 
Simon Tibbett's Avatar
 
Join Date: Apr 2005
Location: Road Atlanta
Posts: 299
Likes: 0
Received 0 Likes on 0 Posts
IT7 Car Feels Slow...

My IT7 car feels slow, obviously it's not suppose to be a rocket but I feel as though I'm down on some HP.

It's all stock minus a header/exhaust, some fancy looking plug wires, and that's about it!

At Road Atlanta it will hit 103-105ish down the back straight before the braking zone into 10.

The car revs smooth and seems to run fine, just lacks some grunt, then again it is a 12A.

Is there anything I can do to gain a few horses in straight line grunt?
Simon Tibbett is offline  
Old 11-16-12, 02:26 PM
  #2  
GET OFF MY LAWN
10 Year Member
iTrader: (1)
 
jgrewe's Avatar
 
Join Date: Feb 2005
Location: Fla.
Posts: 2,838
Likes: 0
Received 0 Likes on 0 Posts
The power is found in the exhaust system on an IT prep RX7. There is a little gain from timing advance 26-28 BTDC IIRC is where you want to be. There are some gains in the midrange with carb tuning but it is more about controling HOW the air gets into the carb. Helmholtz resonance comes into play in a proper intake before the carb and you can smooth out the AFR's.

An ITA RX7 should be able to put about 128 to the wheels
jgrewe is offline  
Old 11-16-12, 06:14 PM
  #3  
Lives on the Forum

 
Kentetsu's Avatar
 
Join Date: Jun 2004
Location: Grand Rapids Michigan
Posts: 11,361
Received 1 Like on 1 Post
Mine always regains some pep after running some Seafoam through the tank...

Other than that, I would look into getting stronger spark on the ignition. I saw unbelievable gains back when I was experimenting with the Transistor Trick ignition system. The only downfall was reliability.



.
Kentetsu is offline  
Old 11-17-12, 07:08 PM
  #4  
Racing is life.
5 Year Member
Thread Starter
 
Simon Tibbett's Avatar
 
Join Date: Apr 2005
Location: Road Atlanta
Posts: 299
Likes: 0
Received 0 Likes on 0 Posts
I'll look into getting more/cool air for sure, I just have the stock intake right now, in fact I don't even have any of the ducting leading to it.

From what another IT7 racer told me based on his speed, I'm about 15mph slower than him down the back straight at Road Atlanta.
Simon Tibbett is offline  
Old 11-17-12, 08:19 PM
  #5  
GET OFF MY LAWN
10 Year Member
iTrader: (1)
 
jgrewe's Avatar
 
Join Date: Feb 2005
Location: Fla.
Posts: 2,838
Likes: 0
Received 0 Likes on 0 Posts
Compression check lately? They will run fine with low compression, just not make power.

15mph is a lot.
jgrewe is offline  
Old 11-18-12, 06:35 AM
  #6  
Racing is life.
5 Year Member
Thread Starter
 
Simon Tibbett's Avatar
 
Join Date: Apr 2005
Location: Road Atlanta
Posts: 299
Likes: 0
Received 0 Likes on 0 Posts
I plan on doing a compression check this week.

I was thinking carb, because the previous owner did a lot of work with a fuel delivery issue and adjusted the carb quite a bit trying to make it run right so I wasn't sure if it was out of whack and needed a tune or something.

I'd assume I need more than just that though to make up a 15mph difference, that's also one of the fastest IT7 cars in my area though so...
Simon Tibbett is offline  
Old 11-18-12, 02:58 PM
  #7  
Full Member
10 Year Member
 
Join Date: Nov 2003
Location: ohio
Posts: 69
Likes: 0
Received 0 Likes on 0 Posts
The Racingbeat air filter kit gained 3hp on the dyno on three different cars. That may be a good start.
allbee is offline  
Old 11-19-12, 01:19 PM
  #8  
Racing is life.
5 Year Member
Thread Starter
 
Simon Tibbett's Avatar
 
Join Date: Apr 2005
Location: Road Atlanta
Posts: 299
Likes: 0
Received 0 Likes on 0 Posts
Yeah I'll be looking into a filter kit/some fresh air ducting and I just found my sound reading from the last race, quite low, I'm thinking maybe the muffler on the car is costing me some power? I'm not even sure of the brand/setup, I know it's only clamped on so it can be removed.

Ah I need next season to start to do a test day and try some things out! :P
Simon Tibbett is offline  
Old 12-02-12, 07:09 AM
  #9  
Needs More Noise
10 Year Member
iTrader: (12)
 
bwaits's Avatar
 
Join Date: Nov 2001
Location: Georgia
Posts: 3,374
Likes: 0
Received 0 Likes on 0 Posts
Originally Posted by Simon Tibbett View Post
I plan on doing a compression check this week.

I was thinking carb, because the previous owner did a lot of work with a fuel delivery issue and adjusted the carb quite a bit trying to make it run right so I wasn't sure if it was out of whack and needed a tune or something.

I'd assume I need more than just that though to make up a 15mph difference, that's also one of the fastest IT7 cars in my area though so...
I have the air cleaner housing you need. Hit me up.

That other car may be one of the fastest, but if you are getting out of 7 correctly, he should not have 15mph on you. I never had a speedo in my car, nor have I competed with 10A and 10B, so cant be much help on the target mph.

What about your gearing, still a 3:9? The fastest cars in the SE are not running 3:9.
bwaits is offline  
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
Kyo
2nd Generation Specific (1986-1992)
6
04-13-19 09:24 AM
astrum
2nd Generation Specific (1986-1992)
24
11-15-17 08:44 AM
stickmantijuana
Microtech
5
08-23-15 11:04 AM


Thread Tools
Search this Thread
Quick Reply: IT7 Car Feels Slow...


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: