Slant *        6        Forum
Home Home Home
The Place to Go for Slant Six Info!
Click here to help support the Slant Six Forum!
It is currently Tue Dec 02, 2025 10:03 am

All times are UTC-08:00




Post new topic  Reply to topic  [ 33 posts ]  Go to page Previous 1 2 3 Next
Author Message
 Post subject:
PostPosted: Fri Jul 09, 2010 5:03 am 
Offline
EFI Slant 6
User avatar

Joined: Fri Jan 05, 2007 2:57 pm
Posts: 355
Location: Florida
Car Model:
Oh yes wind drag, track surface/uneven, temperature/Humidity. Thanks for that hit in the head. Doe :shock:

95 HP difference wow. Now 30 HP loss on my run, don't seem to bad. I would still like to get some of it back!! :?

SV162 Thanks that was easy and did it in the in the A/C. Might find another calc and get some more back. :D

Let's see. If you all were to do the same thing with calc that I did with your time slip, would it read in the same manor? :arrow:

_________________
'72 Image Duster /6 with turbo build up
'03 Ram 2500 4x4 w/HEMI 5sp 4:10 posi
My Twister Page


Top
   
 Post subject:
PostPosted: Fri Jul 09, 2010 5:20 am 
Offline
SL6 Racer & Moderator
User avatar

Joined: Sat Oct 19, 2002 12:06 pm
Posts: 8968
Location: Silver Springs, Fl.
Car Model:
As previously stated, MPH is better for figuring HP. Remember max HP and max torque are at only one RPM, and they are at Different RPM's. 60 foot times are a better indication of the torque the engine is makeing. My 170 engine is making 328 ft/llbs torque at 2900 rpm, and will do 1.79 60 foot time with a 3200 lb car. The rear wheel HP is 204 at about 5500 rpm, and runs 98 mph in the quarter.

One other thing about online, or even calculator programs you can purchase, the "absolute" number is not necessarily acurate (as you have seen, they vary by which calc you use), but the increase/decrease in the numbers on the same calc, after changes to the engine/car, are valid.

_________________
Charrlie_S
65 Valiant 100 2dr post 170 turbo
66 Valiant Signet 170 nitrous
64 Valiant Signet
64 Valiant 4dr 170
64 Valiant 4dr 225


Top
   
 Post subject:
PostPosted: Fri Jul 09, 2010 6:07 am 
Offline
Board Sponsor & Moderator
User avatar

Joined: Mon Oct 21, 2002 11:08 am
Posts: 17244
Location: Blacksburg, VA
Car Model:
I bet they didn't degree the cam and it is way far advanced, and your ign timing should be checked too.

Lou

_________________
Home of Slant6-powered fun machines since 1988


Top
   
 Post subject:
PostPosted: Fri Jul 09, 2010 8:20 am 
Offline
EFI Slant 6
User avatar

Joined: Fri Jan 05, 2007 2:57 pm
Posts: 355
Location: Florida
Car Model:
Quote:
As previously stated, MPH is better for figuring HP. Remember max HP and max torque are at only one RPM, and they are at Different RPM's. 60 foot times are a better indication of the torque the engine is makeing. My 170 engine is making 328 ft/llbs torque at 2900 rpm, and will do 1.79 60 foot time with a 3200 lb car. The rear wheel HP is 204 at about 5500 rpm, and runs 98 mph in the quarter.

One other thing about online, or even calculator programs you can purchase, the "absolute" number is not necessarily acurate (as you have seen, they vary by which calc you use), but the increase/decrease in the numbers on the same calc, after changes to the engine/car, are valid.
If you all were to do the same thing with calc that I did with your time slip, would it read in the same manor? Thanks for joining in on this Charlie.

_________________
'72 Image Duster /6 with turbo build up
'03 Ram 2500 4x4 w/HEMI 5sp 4:10 posi
My Twister Page


Top
   
 Post subject:
PostPosted: Fri Jul 09, 2010 9:05 am 
Offline
EFI Slant 6
User avatar

Joined: Fri Jan 05, 2007 2:57 pm
Posts: 355
Location: Florida
Car Model:
Quote:
I bet they didn't degree the cam and it is way far advanced, and your ign timing should be checked too.

Lou
This sounds like a good place to start getting my Hp back on the track. :)
!Image
I have a few of these I am finishing, this will give me a reason to install one. 8)
Any recemendations on where to set it? Its a small CompCams 260/440.

_________________
'72 Image Duster /6 with turbo build up
'03 Ram 2500 4x4 w/HEMI 5sp 4:10 posi
My Twister Page


Top
   
 Post subject:
PostPosted: Fri Jul 09, 2010 2:24 pm 
Offline
Board Sponsor & Moderator
User avatar

Joined: Thu Oct 17, 2002 7:27 pm
Posts: 14752
Location: Park Forest, Illinoisy
Car Model: 68 Valiant
As well as the car is 60'ing I find it hard to believe the cam is retarded. 2.0 is a damn good 60' for a car that slow.

One other thing you have to remember, a little cubic inch motor will not run as hard downtrack as a bigger motor.

Mine on the hose would run dead even with my buddy's 440 Challenger to half track. From half track on he would put 3 tenths and 7 MPH on me. :cry:

_________________
Official Cookie and Mater Tormentor.


Top
   
 Post subject: Reference
PostPosted: Fri Jul 09, 2010 3:03 pm 
Offline
Board Sponsor & SL6 Racer

Joined: Wed Oct 23, 2002 7:57 pm
Posts: 9077
Location: Waynesboro, Pa.
Car Model: 65 Valiant 2Dr Post
Just as a reference, Ryan's Dart at 3170#(No Driver) went 2.04 60ft time and ran 14.8 in the quarter. You definitely have a good launch but are loosing something on the top end.

Rick


Top
   
 Post subject:
PostPosted: Fri Jul 09, 2010 5:16 pm 
Offline
EFI Slant 6
User avatar

Joined: Thu Jan 13, 2005 1:01 pm
Posts: 482
Location: waynesboro PA
Car Model: 72' Dart Swinger / 62' Valiant
The last test and tune I was at my car ran 16.1 the first time out (usually runs 14.8-15.1). The problems was a clearance issue with my air filter setup (long story) but it was basically choking the engine out. It seemed to run perfect at normal rpm's, even 60ft times were normal, but lost mph/et on the top end. As soon as I changed the filter setup the very next pass was back to normal low 15's. Could there be some type of restriction with your engine? Filter clearance issue, Carb or choke issue? Hopefully there is something simple that will give you that top end power, cause your 6oft times are good.

_________________
Ryan Covalt
62 Plymouth Valiant Race Car 2170# 11.008 @ 117.65 MPH 1/4 Mile Best
72' Dart Swinger Street Car, 4 spd, 3330# 14.061 @96.58 1/4 mile Best


Top
   
 Post subject:
PostPosted: Sun Jul 11, 2010 1:31 pm 
Offline
EFI Slant 6
User avatar

Joined: Fri Jan 05, 2007 2:57 pm
Posts: 355
Location: Florida
Car Model:
Quote:
From what I'm reading, you have a mechanical advance with very light springs that come all in at idle?

CJ
Is that a bad thing :?: Set it and for get it :!: Sounds like a commercial, no i'm not trying to sell you the idea of fixed. :lol: What change would do :idea: welcome.

_________________
'72 Image Duster /6 with turbo build up
'03 Ram 2500 4x4 w/HEMI 5sp 4:10 posi
My Twister Page


Top
   
 Post subject:
PostPosted: Sun Jul 11, 2010 4:20 pm 
Offline
Board Sponsor & Moderator
User avatar

Joined: Thu Oct 17, 2002 7:27 pm
Posts: 14752
Location: Park Forest, Illinoisy
Car Model: 68 Valiant
Just as a reference, my GTO went a 2.04 60' on a 13:89 pass.

Last night in the crap air down at 41 it was going 2.10 and 14:50. :shock:

_________________
Official Cookie and Mater Tormentor.


Top
   
 Post subject:
PostPosted: Mon Jul 19, 2010 3:44 pm 
Offline
EFI Slant 6
User avatar

Joined: Fri Jan 05, 2007 2:57 pm
Posts: 355
Location: Florida
Car Model:
I will make one more night of testing then some kind of change. Any other ideas :?: Now it has a loss of 30HP from the 60' to 1/4 mile. I really don't want to see any loss!!! Is that passable?

_________________
'72 Image Duster /6 with turbo build up
'03 Ram 2500 4x4 w/HEMI 5sp 4:10 posi
My Twister Page


Top
   
 Post subject:
PostPosted: Mon Jul 19, 2010 5:26 pm 
Offline
SL6 Racer & Moderator
User avatar

Joined: Sat Oct 19, 2002 12:06 pm
Posts: 8968
Location: Silver Springs, Fl.
Car Model:
Quote:
I will make one more night of testing then some kind of change. Any other ideas :?: Now it has a loss of 30HP from the 60' to 1/4 mile. I really don't want to see any loss!!! Is that passable?
Not possible. You are measuring two different things at two different rpm. Look at a dyno chart, and compare it to the RPM at the points you are measuring. Also, at one point you are measuring ET (60 ft). and the other point you are measuring MPH (1/4 mile).

_________________
Charrlie_S
65 Valiant 100 2dr post 170 turbo
66 Valiant Signet 170 nitrous
64 Valiant Signet
64 Valiant 4dr 170
64 Valiant 4dr 225


Top
   
 Post subject:
PostPosted: Mon Jul 19, 2010 6:04 pm 
Offline
EFI Slant 6
User avatar

Joined: Thu Jan 13, 2005 1:01 pm
Posts: 482
Location: waynesboro PA
Car Model: 72' Dart Swinger / 62' Valiant
I don't have any great suggestions, but for a reference here is my time slip broken down by a hp calculator (3330lbs):

60ft time: 2.039 171.97 whp
1/8 mile: 9.437 180.48 whp
1/8 mile: 72.48mph 186.20 whp
1/4 mile: 14.83 179.90 whp
1/4 mile: 91.22mph 180.54 whp

I ran your time slip on the same calculators as a comparison. (3400lbs)
60ft time: 2.0 187.05 whp
1/8 mile: 10.0 154.87 whp
1/4 mile: 16.27 140.43 whp
Looks like this calculator shows an even bigger difference! It would be interesting to see what it says with your mph numbers.

One thing with a 60ft calculator is the slightest et difference greatly affects the hp numbers. Did you run an exact 2.0 60ft? I ran your numbers with a 60 ft of 2.05, and hp drops to 172.5hp. The 60ft calculator is extremely sensitive. You may have known that already, but I didn't realize how big of a difference a few hundredths makes on the 60ft calculator. Hope this at least gives you a reference.

_________________
Ryan Covalt
62 Plymouth Valiant Race Car 2170# 11.008 @ 117.65 MPH 1/4 Mile Best
72' Dart Swinger Street Car, 4 spd, 3330# 14.061 @96.58 1/4 mile Best


Top
   
 Post subject:
PostPosted: Tue Jul 20, 2010 9:07 pm 
Offline
SL6 Racer

Joined: Tue Sep 01, 2009 8:06 am
Posts: 188
Location: Biggs Ca 95917
Car Model:
You are not losing any hp,your trap speed /weight formula will give you the hp for that particular run. You cannot use 60 ft to compute hp. as an example the Dart i ran last year did 1.90 sixty s.At the last Redding race last year had six straight 1.90 and a1.89. Why? the car weight 2450 with driver, 4,30 rear gear with spool ,a sticky tire and a 3600 stall converter.Best et 14.99,engine is 100% internally stock,has a hedder and a holley500 2 barrel. Fastest speed with this combo only 85mph,so i have at best 150hp but the car would outrun a lot of 13 second cars to the 330 mark then the accelaration went away. Use your trap speed to compute hp ,then tune for speed and then you can calculate what your best potential e.t would /should be.


Top
   
 Post subject:
PostPosted: Thu Jul 22, 2010 9:06 am 
Offline
SL6 Racer

Joined: Tue Sep 01, 2009 8:06 am
Posts: 188
Location: Biggs Ca 95917
Car Model:
I had another theory ,not sure what rear end gears you have. On my dart the 1/4 milr rpms were 5100 with 3.91 gears and 5000 with 4.30 gears, makes no sense. Howeve rhe converter is too loose for this combo so when i go into high gear the converter is not fully locked up causing slippage and loss of et. My converter will only go 2800 max, you say yours goes to 3000. That may explain the loss of et the last eight . I do agree you should be running quicker from the 1/8 to the 1/4


Top
   
Display posts from previous:  Sort by  
Post new topic  Reply to topic  [ 33 posts ]  Go to page Previous 1 2 3 Next

All times are UTC-08:00


Who is online

Users browsing this forum: Bing [Bot] and 8 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  
Powered by phpBB® Forum Software © phpBB Limited