ECUTune Stage III dyno pull videos - Page 2

mikecg · #16 11-20-2006, 01:00 PM

Hmmm only a 18hp difference between 9lbs with daul exhaust and 12lbs with single. Ya Tom, you defenitly need to look into the exhaust.

Paticularly in the area between the manifolds and the Y-Cat. That is were the largest amount of restriction is. Those pipes are only like 1.5 inch in diameter. Lose the Y-cat and run 2 hi-flow Cats that are larger diameter. If you dont want duals, I'd recommend at least 2.25in off the manifolds, through 2 high flows Y into a 2.5 to 3inch out to the rear. Just beware of resination. I'd definitly put in some kind of resinator no matter what kind of exhaust you run.

longassname · #17 11-20-2006, 01:59 PM

I haven't gotten a chance to download the dynojet software and see if I can figure out how to put the plots x axis on rpms and overlay Mike's and Tom's plots but yes even just looking at them as is it's easy to see that Tom's exhaust is restricted.

Mike's peak power is out at 90mph. Tom's is at 75. It looks like back around 60mph he starts having problems clearing the exhaust from the cyllinders. He should see big power gains with a big exhaust upgrade. I would not be suprised if Tom is having belt slip issues because of the compressor having to pump against the exhaust.

Both of them can see big power gains (after TOM upgrades his exhaust) from new cams. With the cam I just spec'd in the cam thread I think they can both get their torque plots into pretty flat lines and their power plots into flat lines following the slope from 60mph and lower.

oab_au · #18 11-20-2006, 02:50 PM

If it is the exhaust that is restricting the engine, you should see a rise in manifold pressure, at the same time. I wonder if he noticed the boost gauge at that time.

Harvey.

oab_au · #19 11-20-2006, 03:02 PM

Quote:

Originally Posted by mikecg

Hmmm only a 18hp difference between 9lbs with daul exhaust and 12lbs with single. Ya Tom, you defenitly need to look into the exhaust.

Paticularly in the area between the manifolds and the Y-Cat. That is were the largest amount of restriction is. Those pipes are only like 1.5 inch in diameter. Lose the Y-cat and run 2 hi-flow Cats that are larger diameter. If you dont want duals, I'd recommend at least 2.25in off the manifolds, through 2 high flows Y into a 2.5 to 3inch out to the rear. Just beware of resination. I'd definitly put in some kind of resinator no matter what kind of exhaust you run.

Looking for a pict of Toms exhaust, as it is now? Anywhere?

Harvey.

longassname · #20 11-20-2006, 03:05 PM

possibly but not necessarily. All kinds of weird things can happen, all bad. The blower can win out and still clear the cyllinder during overlap at the cost of more power to drive it. The blower could loose the battle without the belt slipping. The blower could loose the battle with belt slip. The blower could win the battle with belt slip. There could be a tie with belt slip. There could be a tie without belt slip. And favorite of all, things can bounce back and forth between any number of those conditions. Manifold pressure can end up higher, lower, unchanged, or all over the place.

oab_au · #21 11-20-2006, 03:26 PM

Quote:

Originally Posted by longassname

possibly but not necessarily. All kinds of weird things can happen, all bad. The blower can win out and still clear the cyllinder during overlap at the cost of more power to drive it. The blower could loose the battle without the belt slipping. The blower could loose the battle with belt slip. The blower could win the battle with belt slip. There could be a tie with belt slip. There could be a tie without belt slip. And favorite of all, things can bounce back and forth between any number of those conditions. Manifold pressure can end up higher, lower, unchanged, or all over the place.

Well that clears it up

You been taking confusing lessions from Trevor.

The boost gauge is a sure way to see what the flow is doing. Need all the feedback you can get, to work out what is happening.

Harvey.

oab_au · #22 11-20-2006, 03:31 PM

If somebody can translate the MPH figures to RPM, off what ever the gearing was, it would help to see what is happening where. Guessing is not close enought.

Harvey.

cdigerlando · #23 11-20-2006, 03:50 PM

Great job guys. Great to see your projects working out well. I had a question regarding some of the plots. Is there any reason why Mike's seems to be running higher A/Fs? Is it due to the lower boost level? It was my understanding that this 12 psi kit was to run AFs as low as 10.5:1. I'm not sure about the 9 psi kit.

Phast SVX · #24 11-20-2006, 05:13 PM

Great results guys, cant wait to see what Toms car puts out when he gets it sorted.

Quote:

Originally Posted by oab_au

Well that clears it up

You been taking confusing lessions from Trevor.

The boost gauge is a sure way to see what the flow is doing. Need all the feedback you can get, to work out what is happening.

Harvey.

Harvey.
There in lies your error. You can have the same pressure ratio at the cost of a lower density ratio, and therefore not just look at the boost pressure but we must also look at temp to come to the conclusion you are trying to reach

TomsSVX · #25 11-20-2006, 05:50 PM

exhaust is comming... I am thinking dumps but I may do a total revamp. Intake is comming too. I am busy getting the garage ready... plus I have all winter to het this figured out

Tom

SVXRide · #26 11-20-2006, 06:38 PM

Mike,
Nice videos! It does look like Tom's belt is slipping in the one video, but then again, it could just be the lighting (watch where the the belt goes around the a/c compressor)

Interesting to note that even with the Gruppe N motor mounts that the engine is visibly torquing around...hate to think what would be happening if the stock mounts were in there

-Bill

TomsSVX · #27 11-20-2006, 07:25 PM

they would rip in half and hit the keepers?

GroupN trans mount too

Tom

SVXRide · #28 11-20-2006, 07:45 PM

Quote:

Originally Posted by TomsSVX

they would rip in half and hit the keepers?

GroupN trans mount too

Tom

That's what I was thinking....might be time for a torque strap

-Bill

oab_au · #29 11-20-2006, 09:04 PM

Quote:

Originally Posted by Phast SVX

Great results guys, cant wait to see what Toms car puts out when he gets it sorted.

Harvey.
There in lies your error. You can have the same pressure ratio at the cost of a lower density ratio, and therefore not just look at the boost pressure but we must also look at temp to come to the conclusion you are trying to reach

Hang on Phil,

this is a PD blower, don't have the same temps as the turbo. What I would be look at would be a smooth reading that only increased slightly. Any increase in pressure over the normal maximum, shows that the intake, or the exhaust is not passing it.
A sudden rise is usually exhaust gas pressure build up. Intake restriction, builds up more gradually, to a higher bressure.

This is a bit harder to do with a turbo, due to the fast rise in boost. Turbos have there own set of problems.

Harvey.

longassname · #30 11-20-2006, 09:41 PM

Are you two working your own grumpy old men sequel?

It didn't really seam confusing to me. Let me put it in simpler terms. Because we only have a 6 rib belt and a tiny supercharger pulley instead of boost spikes we can get belt slip. Depending on the degree of slip boost can stay stable, have dips, or have spikes.

Quote:

Originally Posted by oab_au

Well that clears it up

You been taking confusing lessions from Trevor.

The boost gauge is a sure way to see what the flow is doing. Need all the feedback you can get, to work out what is happening.

Harvey.