Almost there but not quite

mech2161 said:
Mine peaked and dropped off. After the dyno I swapped out the full cuts for 191's. I want to get back on the dyno once I get everything done. Full cuts to 191's, two or three clicks back in the 5k gov springs and a waste gate. The dyno sheet is too big for an attachment. I have it posted somewhere, just need to find it.
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I would like to see the difference the 191's over the full cuts make. I'm not sure thats my problem, but I'm also not sure I need these full cuts to meet my goal.
 
Dave, how does your truck feel on the street above 2800 rpms?

I would suspect the drive difference you are seeing is a result of the cam and head work (maybe cam more then head work). Ofcourse Chris had indicated they've been able to get the 74/83 wheen and .90 housing a bit tighter then the days of my 468 so perhaps that also plays a part (maybe Chris will chime in). I'm no expert but that's not a huge difference but get the gate on and find out first hand if there's some power there. That's some decent boost in my opinion taking the cam and head work in consideration.

Keep us updated i'm reall interested to see what you come up with! This is a manual truck right?

Lasty, any videos?
 
NickTF said:
Dave, how does your truck feel on the street above 2800 rpms?

I would suspect the drive difference you are seeing is a result of the cam and head work (maybe cam more then head work). Ofcourse Chris had indicated they've been able to get the 74/83 wheen and .90 housing a bit tighter then the days of my 468 so perhaps that also plays a part (maybe Chris will chime in). I'm no expert but that's not a huge difference but get the gate on and find out first hand if there's some power there. That's some decent boost in my opinion taking the cam and head work in consideration.

Keep us updated i'm reall interested to see what you come up with! This is a manual truck right?

Lasty, any videos?
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It feels better on the street, but still falls back some but not like it did on the dyno. Boost numbers on the street are also 10+ psi higher than on the dyno ( i know this is normally the case with the bigger chargers). The interesting part is it will hold 60+ psi till 2800-3000 rpm then I lose a little boost like 5 psi, with the 5 k springs I should hold that boost pressure till over 4k right? I really need to check my fuel press and order that other spring we talked about yesterday.

Here is the video of the 585 run, I'm uploading the other video now.

http://www.youtube.com/watch?v=pbd4pwaaEcw
 
Dave...
If the AD's fuel pressure is till set at 30 or above and has been since you installed it you will find zero gain in power going any higher with fuel pressure.

You can see at the end of your dyno run its still hazing heavy so I feel your fuel system is not the issue.

The drive pressure is part of the wall your finding on your sheet and you should be able to duplicate that on the street easily also.With 20spi of drive pressure above your boost levels and the high timing this could lead to an early exit of the headgasket so you will want to rid yourself of that before you pull.

TJ...
One thing you have to remember though,you have a head in stock form that will outflow our heads when they are ported.Then throw in a better piston bowl design and you should do alot more than a 12v truck.
 
Hammer said:
Dave...
If the AD's fuel pressure is till set at 30 or above and has been since you installed it you will find zero gain in power going any higher with fuel pressure.

You can see at the end of your dyno run its still hazing heavy so I feel your fuel system is not the issue.

The drive pressure is part of the wall your finding on your sheet and you should be able to duplicate that on the street easily also.With 20spi of drive pressure above your boost levels and the high timing this could lead to an early exit of the headgasket so you will want to rid yourself of that before you pull.

TJ...
One thing you have to remember though,you have a head in stock form that will outflow our heads when they are ported.Then throw in a better piston bowl design and you should do alot more than a 12v truck.
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My head is held down with 12mm studs, oringed, and I have a .020 over headgasket. I do plan on hooking up my external gate before I start pulling, but I will also be running 30* or very close to it when I do pull.

I checked my fuel press today

with the truck off 29psi
with the truck ideling 26psi
truck @ 2500 rpm no load 28psi
 
Obviously I don't know were everything else is set at but I will tell you that 30* timing is not for the dyno, can't see the smoke level and how it comes in so I don't know how the AFC is tuned or what DV's are in it. If you want it to dyno well it will have to Rev, no choking out and starting at low RPM's gains nothing, you've got to get on top of the turbo/s quick then add fuel via the AFC.

Jim
 
Dave...
Mine was held down the same way,had the same head gasket and had less timing(24 degrees) when I was trying tog et the small Garrett GT3788R Stage 3 over the top and drive pressures like what your seeing caused the gasket to fail.I did mine with simular drive pressure readings when I was acting like a fool chasing my buddies built twin chargered WRX STi.I'd say it would be worth your time to get that vented out and get rid of the exhaust wall your seeing,it may free up a little top end but I am convinced that it will not tear the wall completely down.

I really do not think that fuel pressure is one of your issues.With what your seeing unloaded the numbers you laid down are not going to change with a spring change in the pump.When I dynoed mine back earlier last spring the pump on mine was a 150/180(180gph that was failing)FASS that was at 24psi and pulled down to 7psi under load and when it was dynoed last fall it was a 180/200 FASS(200gph) and the pressure was at 50psi at idle and under load as it never changed.As a matter of fact neither pressure or volume made any difference in the overall number mine ran and the charts can be laid on top of each other they are so close to the same.

Congrats on the nice runs BTW.

On Edit..
Jim....
In Jetpilots old Black Bottle rocket when it had the Stoopid pump on it and the 40/3B twins at over 30 degrees of timing(I forget where he had it set)it made well into the 7's on fuel.When he sold it the gentleman who bought it lowered the timing to drive it daily down around 25 degrees and it cost him over 100 on the jet.So if your saying 30 is too high,what did you find with your that was your best setting?.Mine has been set down at 20 since early last fall after I pushed the headgasket out and timing from what its at now to when we had it at 25 made zero difference in roll numbers.
 
Last edited:
Jim Fulmer said:
Obviously I don't know were everything else is set at but I will tell you that 30* timing is not for the dyno, can't see the smoke level and how it comes in so I don't know how the AFC is tuned or what DV's are in it. If you want it to dyno well it will have to Rev, no choking out and starting at low RPM's gains nothing, you've got to get on top of the turbo/s quick then add fuel via the AFC.

Jim
Click to expand...

I have full cuts in now and I'm going to swap a set of 191's in. There is a good bit of smoke comming out of the exhaust but I think that is mostly due to the full cuts. In my afc I have the tst heavy spring set to go full fuel @ 40psi, two thin washers, ground barrel, and the housing is halfway.

i will bring the timing down for the next run to the 24-26 range

Hammer said:
Dave...
Mine was held down the same way,had the same head gasket and had less timing(24 degrees) when I was trying tog et the small Garrett GT3788R Stage 3 over the top and drive pressures like what your seeing caused the gasket to fail.I did mine with simular drive pressure readings when I was acting like a fool chasing my buddies built twin chargered WRX STi.I'd say it would be worth your time to get that vented out and get rid of the exhaust wall your seeing,it may free up a little top end but I am convinced that it will not tear the wall completely down.

I really do not think that fuel pressure is one of your issues.With what your seeing unloaded the numbers you laid down are not going to change with a spring change in the pump.When I dynoed mine back earlier last spring the pump on mine was a 150/180(180gph that was failing)FASS that was at 24psi and pulled down to 7psi under load and when it was dynoed last fall it was a 180/200 FASS(200gph) and the pressure was at 50psi at idle and under load as it never changed.As a matter of fact neither pressure or volume made any difference in the overall number mine ran and the charts can be laid on top of each other they are so close to the same.

Congrats on the nice runs BTW.
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Thank you andy,

I'm still going to get the spring just for a peice of mind thing. I will get my gate hooked up and I plan on dropping my timing before I dyno at the spring fling.
 
A couple clicks on the gov springs made a big difference on my truck. The dyno runs I made were in late Oct. Thinking that pulling season was over I had taken two clicks out to make it easier to drive and not be so touchy. I couldn't understand why it peaked out so soon on the dyno. The folowing weekend a local club put on another pull to make up for a rain out. Previous pulls it carried 36-3700 rpms down the track. That pull it only carried 3000 rpms down the track. If you listen to the videos you can hear the difference.

Loose clay track, 27* timing 3600r's.

[MEDIA]http://www.youtube.com/watch?v=dCAa1whC-h4[/MEDIA]

Very loose damp clay, 27* timing with two clicks out of the gov springs 3000r's.

[MEDIA]http://www.youtube.com/watch?v=S72823GX5Tw[/MEDIA]
 
mech2161 said:
A couple clicks on the gov springs made a big difference on my truck. The dyno runs I made were in late Oct. Thinking that pulling season was over I had taken two clicks out to make it easier to drive and not be so touchy. I couldn't understand why it peaked out so soon on the dyno. The folowing weekend a local club put on another pull to make up for a rain out. Previous pulls it carried 36-3700 rpms down the track. That pull it only carried 3000 rpms down the track. If you listen to the videos you can hear the difference.

Loose clay track, 27* timing 3600r's.

[MEDIA]http://www.youtube.com/watch?v=dCAa1whC-h4[/MEDIA]

Very loose damp clay, 27* timing with two clicks out of the gov springs 3000r's.

[MEDIA]http://www.youtube.com/watch?v=S72823GX5Tw[/MEDIA]
Click to expand...


hum, I'll have to do some playing arround with them. i'm droping my timing today to 22* to try and light the charger a little faster
 
Dropping the timing will spool it faster. It will also lower the top end. Our set up are so similar it will be nice to get it figured out for both of us. I think the waste gate is going to be the biggest help.
 
I made a best of only 631 with that S465 and as Andy said, the 24v head flows a little better. it was definitely choking on the top without a gate tho.
 
mech2161 said:
Dropping the timing will spool it faster. It will also lower the top end. Our set up are so similar it will be nice to get it figured out for both of us. I think the waste gate is going to be the biggest help.
Click to expand...

I hope so, I have a 50mm ED gate that will go on before dyno on the 20th. 22* is what I used to have my timing set at before i put the scheid pump on, spooled great on the street.


getblown5.9 said:
I made a best of only 631 with that S465 and as Andy said, the 24v head flows a little better. it was definitely choking on the top without a gate tho.
Click to expand...

I remember that run at bretts. Did you have full cuts or 191's? I can't remember if we swaped before or after that run
 
that was the full cuts.

for comparison to your runs, it did 575 with the plate all the way back.
 
well I droped my timing back down to 22* took her out for a test spin, first hard pull the charger came on very strong @ 1900 rpm and blew a intercooler boot off. I still have the stock boots and clamps on my truck, I'll have to recheck them to make sure there all sealing and not cut or riped.
 
94 12valve said:
well I droped my timing back down to 22* took her out for a test spin, first hard pull the charger came on very strong @ 1900 rpm and blew a intercooler boot off. I still have the stock boots and clamps on my truck, I'll have to recheck them to make sure there all sealing and not cut or riped.
Click to expand...

Sounds good, I run 20 and a Silver Bullet smacks at 1800 but I do have a stock cam.

Jim
 
94 12valve said:
I hope so, I have a 50mm ED gate that will go on before dyno on the 20th.
Click to expand...

Are you going to be dynoing at Mid-Atlantic again? I've never seen a dyno run before and would love to see one for the first time.
 
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