Login    Forum    Search    FAQ

Board index » Racing Forum » Engine & Cylinder Head Tech




Post new topic Reply to topic  [ 17 posts ]  Go to page 1, 2  Next
Author Message
 Post subject: Dyno Questions/Converter
 Post Posted: Fri May 14, 2010 7:24 am 
Offline
User avatar

Joined: Wed Apr 19, 2006 8:20 pm
Posts: 5852
Location: N.J.
Going to the dyno soon hopefully if things start to go better than they have lately... Anyway going to need some converter #'s to shoot for so where should the rpm's start to get some info for a converter...

_________________
Image
running E85
Best ET 8.07
Best MPH 170.71
Barry


Top 
 Profile  
 
 Post Posted: Fri May 14, 2010 8:37 am 
Offline
Moderator
User avatar

Joined: Tue Apr 18, 2006 3:20 pm
Posts: 1457
Location: Missouri
Engine dyno? or Chassis dyno?

Rick


Top 
 Profile  
 
 Post Posted: Fri May 14, 2010 10:03 am 
Offline
User avatar

Joined: Wed Apr 19, 2006 8:20 pm
Posts: 5852
Location: N.J.
engine =;

_________________
Image
running E85
Best ET 8.07
Best MPH 170.71
Barry


Top 
 Profile  
 
 Post Posted: Fri May 14, 2010 11:55 am 
Offline
Moderator
User avatar

Joined: Tue Apr 18, 2006 3:20 pm
Posts: 1457
Location: Missouri
I normally have a pretty good idea where the TQ & HP peaks will happen and start a couple hundred rpm below expected peak TQ rpm. On the first few pulls I normally do short pulls where I stop it early. Then pull it on up past peak HP rpm. I see a lot of dyno sheets where people don't really pull it high enough to tell best shift rpm. On at least one pull near the end, make sure you pull it high enough that the power is well past the hump and declining.

On my 414 I think we started most of them around 4800 to get good accel readings by 5000 and up. The TQ peak was 5300 but was virtually flat from 5000-6000 and HP peaking at 6900. Most pulls went to 7500, but we started off pulling to 7000 or 7200 rpm until most tuning was complete.

The engine from your Beretta I assume? What changes?
Good luck and let us know the #'s.

Rick


Top 
 Profile  
 
 Post Posted: Fri May 14, 2010 12:41 pm 
Offline
User avatar

Joined: Wed Apr 19, 2006 8:20 pm
Posts: 5852
Location: N.J.
The new motor.......and I say new cause everything is new...540 Bowtie block,Wisco pistons,Oliver rods,Callies crank,Brodix BB2Xtra heads,Victor manifold, 1150 dominator that I sent to Mark in Florida to check it out and he ran
it on his dragster....Hope to make 850 hp...

I have a 8" that has been done over and my be it can be made to work with this new motor but I am thinking a 9" will work better and be more constant and that's what I am after...
This is what it looks like for now...
Image

_________________
Image
running E85
Best ET 8.07
Best MPH 170.71
Barry


Top 
 Profile  
 
 Post Posted: Fri May 14, 2010 1:00 pm 
Offline
User avatar

Joined: Mon Oct 29, 2007 7:07 pm
Posts: 1422
Location: Florida
If the heads are decent it should make 850 and then some. Bruce/NOMAD hit 800 on his pump gas 540 with AFR heads. And we know the carb works.... =;

I'd start the pul no higher than around 4800, peak torque should fall in the 5000-6000 range. Plan on converter stall to be 300- 500 RPM over peak torque for best ET.


Top 
 Profile  
 
 Post Posted: Fri May 14, 2010 1:28 pm 
Offline
User avatar

Joined: Wed Apr 19, 2006 8:20 pm
Posts: 5852
Location: N.J.
sprag or spragless???

_________________
Image
running E85
Best ET 8.07
Best MPH 170.71
Barry


Top 
 Profile  
 
 Post Posted: Fri May 14, 2010 1:59 pm 
Offline
User avatar

Joined: Mon Oct 29, 2007 7:07 pm
Posts: 1422
Location: Florida
If you run primarily 1/8 mile, or are more concerned with consistency and reliability get a steel stator spragless. If you are looking for max ET/MPH in the 1/4 I would look at the newer 10 element mechanical diode. A little more money than a sprag, but from what I hear they are almost indestructible. Take your dyno sheets to who ever you purchase your converter from.


Top 
 Profile  
 
 Post Posted: Fri May 14, 2010 4:57 pm 
Offline

Joined: Tue Sep 01, 2009 9:55 am
Posts: 26
Location: Illinois
I suggest a spragless converter from Trans Specialties. When I switched I didn't lose any performance in the 1/4 mile. You can also check with scdiv1 on drr... he didn't lose any performance either when he had TSI convert his converter.

_________________
Scott

2007 & 2009 Gateway S/Pro Champion
Image
420 SBC 1.085, 4.85@140.5, 7.67@172.7
Image


Top 
 Profile  
 
 Post Posted: Fri May 14, 2010 7:18 pm 
Offline
User avatar

Joined: Wed Apr 19, 2006 8:20 pm
Posts: 5852
Location: N.J.
There are no 1/8 mile tracks in N.J. and the ones that are in PA that I visit are also 1/4 mile.....

_________________
Image
running E85
Best ET 8.07
Best MPH 170.71
Barry


Top 
 Profile  
 
 Post Posted: Fri May 14, 2010 9:10 pm 
Offline
User avatar

Joined: Mon Oct 29, 2007 7:07 pm
Posts: 1422
Location: Florida
Most tracks here are 1/4, but have gone to an 1/8 mile to save $ on track prep. As far as spragless... Find even ONE normally aspirated Stock, Super Stock, or Comp eliminator car with a spragless converter. Take the same converter except change from sprag to spragless or vise versa, the spragless will never be any faster as long as the sprag is not slipping. If the turbine speed approaches the pump speed and wants to unlock the spragless converter and can't, it will slow the car versus one with a sprag. My TSI converter was converted from a 5 element diode to a spragless, it lost a tenth and 2-3 MPH. The more power the car makes down track the longer it will stay locked and the less effect a spragless will make, but it will still reach that it wants to unlock and can't. A blown or heavy nitrous car may stay on the converter hard enough that would not unlock the stator during the run, they are a good candidate for a spragless. What the spragless does provide is durability and with no slippage, consistency over the life. You have to decide if the potential loss of time is worth it.


Top 
 Profile  
 
 Post Posted: Fri May 14, 2010 11:11 pm 
Offline

Joined: Sat Feb 24, 2007 6:55 pm
Posts: 847
Location: NW MO.
"IF" traction isn't a problem, I think the converter for best et, and consistency will be the same converter.

For consistency, you need the car to spend as little time as possible from the time the trany brake is released, till the timer starts. This requires a hard leaving car.!

For lowest et, you absolutly must get the 60' time as low as possible. This requires a hard leaving car!

If traction "IS" a problem, an improvement there will help both.

I also agree that the engine should be pulled past peak HP, to find where it falls off, in order to get a good idea of best shift point.

I know of an engine that needed shifted higher than I thought it should need shifted for low et. It was dynoed this winter, and the shift point the engine needed was making almost the same power as the rpm it fell back to after the shift. Basicaly the dyno validated what was already learned at the track.

_________________
Slow racing is better than no racing!

Randy


Top 
 Profile  
 
 Post Posted: Sun May 16, 2010 6:32 pm 
Offline

Joined: Tue Sep 01, 2009 9:55 am
Posts: 26
Location: Illinois
jmarkaudio wrote:
Most tracks here are 1/4, but have gone to an 1/8 mile to save $ on track prep. As far as spragless... Find even ONE normally aspirated Stock, Super Stock, or Comp eliminator car with a spragless converter. Take the same converter except change from sprag to spragless or vise versa, the spragless will never be any faster as long as the sprag is not slipping. If the turbine speed approaches the pump speed and wants to unlock the spragless converter and can't, it will slow the car versus one with a sprag. My TSI converter was converted from a 5 element diode to a spragless, it lost a tenth and 2-3 MPH. The more power the car makes down track the longer it will stay locked and the less effect a spragless will make, but it will still reach that it wants to unlock and can't. A blown or heavy nitrous car may stay on the converter hard enough that would not unlock the stator during the run, they are a good candidate for a spragless. What the spragless does provide is durability and with no slippage, consistency over the life. You have to decide if the potential loss of time is worth it.


My opinion is that we are bracket racing and having a spragless converter means you have one less thing to cause a round loss. We didn't slow down when we made the switch so that was an extra bonus.

Did TSI do the conversion from diode to spragless?

_________________
Scott

2007 & 2009 Gateway S/Pro Champion
Image
420 SBC 1.085, 4.85@140.5, 7.67@172.7
Image


Top 
 Profile  
 
 Post Posted: Sun May 16, 2010 6:49 pm 
Offline
User avatar

Joined: Thu Apr 20, 2006 8:57 pm
Posts: 708
Well I can def say that MY car with a spragless verter done by T.S.I SLOWED the car like was said a tenth and I losted 2-3 mph...And everyone I talked to said the EXACT same thing as
jmarkaudio(Mark) stated.Just 1 thing less to break,thats all...As Far as consistancy,only time will tell with enough time slips to compare to old slips... =;
If I had Barry's money =; ....Mechanical Diode setup.. \:D/

_________________
Image

THE ATOMIC BANEGA(BANANA/VEGA)
http://www.youtube.com/watch?v=0BagEEa8JDo


Top 
 Profile  
 
 Post Posted: Thu May 20, 2010 10:10 am 
Offline

Joined: Tue Apr 13, 2010 9:36 am
Posts: 12
I must have missed if you were spraying. The dyno numbers won't reflect the whack from n2o and the torque numbers won't be reliable. We have changed to the neal chance converter, 10 element 'diode', adjustable and it seems to work really good.


Top 
 Profile  
 
Display posts from previous:  Sort by  
 
Post new topic Reply to topic  [ 17 posts ]  Go to page 1, 2  Next

Board index » Racing Forum » Engine & Cylinder Head Tech


Who is online

Users browsing this forum: No registered users and 6 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

Search for:
Jump to: