Maggie and Nitrous - Stepped PSI?
03-22-2009, 07:13 PM
#1
Maggie and Nitrous - Stepped PSI?
Going through logs at the track from yesterday and I see something I've never noticed before.
Green line is logged boost but basically 9psi through 1st gear, 9.3 psi through 2nd, then over 10psi in spots through third.
Given it some thought and I have an idea whats going on.
What do you think?
Yeah 167 degree IAT temps and 12 degrees of timing.
Green line is logged boost but basically 9psi through 1st gear, 9.3 psi through 2nd, then over 10psi in spots through third.
Given it some thought and I have an idea whats going on. What do you think?
Yeah 167 degree IAT temps and 12 degrees of timing.
03-22-2009, 07:55 PM
#3
Yeah it's definitely load dependent. I think I understand why a turbo would react that way but still not quite understanding how a fixed displacement blower would.
If I had the cash I'd be all over the TVS. That log is 75 shot of nitrous and all I can throw methanol. So much for chemical cooling this thing.
If I had the cash I'd be all over the TVS. That log is 75 shot of nitrous and all I can throw methanol. So much for chemical cooling this thing.
03-23-2009, 03:17 PM
#4
Depending on the amount of nitrous you are using you can and will see boost pressures rise. The nitrous is trying to expand, and the blower is trying to compress.
The 420 megablower I had a sbc,pulleyed at 8-10 psi. 200shot of nitrous would peg a 15lb gauge.
And really make that old blower sound alot differnt.
Boost down and nitrous up, that will aid in your cooling.
The 420 megablower I had a sbc,pulleyed at 8-10 psi. 200shot of nitrous would peg a 15lb gauge.
And really make that old blower sound alot differnt.
Boost down and nitrous up, that will aid in your cooling.
03-23-2009, 05:23 PM
#5
Depending on the amount of nitrous you are using you can and will see boost pressures rise. The nitrous is trying to expand, and the blower is trying to compress.
The 420 megablower I had a sbc,pulleyed at 8-10 psi. 200shot of nitrous would peg a 15lb gauge.
And really make that old blower sound alot differnt.
Boost down and nitrous up, that will aid in your cooling.
The 420 megablower I had a sbc,pulleyed at 8-10 psi. 200shot of nitrous would peg a 15lb gauge.
And really make that old blower sound alot differnt.
Boost down and nitrous up, that will aid in your cooling.
Hey, 5 psi boost and 200 shot of nitrous
Kinda defeating the purpose 
Any difference with boost pressure raise or fall with a "wet" or "dry" shot? Is meth really a boost cooler or just a supplemental fuel source?
So much tuning involved and pulley change and nozzzle change... will anyone find the magic psi and hp shot ratio? Where is the happy medium.....
----KYSILVERADO---- What size pulley are you running? The Dyno Tuner told me he recorded 11psi with no spray on the chart in a third gear pull.. does that mean it could be higher in the 1/4 mile?
So much tuning involved and pulley change and nozzzle change... will anyone find the magic psi and hp shot ratio? Where is the happy medium.....
----KYSILVERADO---- What size pulley are you running? The Dyno Tuner told me he recorded 11psi with no spray on the chart in a third gear pull.. does that mean it could be higher in the 1/4 mile?
I'm running a 2.9 pulley. I would say that in your case yes the PSI could go higher at the track if mine is any indicator, higher load, higher boost on the spray. Dynos don't load as well as the road as I understand.
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03-23-2009, 07:02 PM
#8
Not sure I want to see boost higher than 11psi .....isnt that danger zone? 
If I dont want to run meth all the time does it need to be tuned and just be added to existing setup but used to cool?
Is it really possible to force feed a blower? I was thinkin of closing off the side of my Volant air box that is closest to the fender and just having the drop down tow hook scoop to feed the Radix but that just seem like a small tube/hole and a huge restriction until I am going like 100mph.... But I also believe that going from a 78mm to 90mm TB would be more air = more boost but it was the opposite......( P=F/A ) bigger means less boost
If I dont want to run meth all the time does it need to be tuned and just be added to existing setup but used to cool? Is it really possible to force feed a blower? I was thinkin of closing off the side of my Volant air box that is closest to the fender and just having the drop down tow hook scoop to feed the Radix but that just seem like a small tube/hole and a huge restriction until I am going like 100mph.... But I also believe that going from a 78mm to 90mm TB would be more air = more boost but it was the opposite......( P=F/A ) bigger means less boost
I'm not afraid of 11 psi so long as I'm fueling it well... which I'm working on right now from those logs.
There is no doubt "ram air" works on a N/A engine. Should help a FI also.
Don't believe it's done it till going to the 80e. Strange.
03-23-2009, 10:24 PM
#10
I am not running meth and have 42# injectors with an inline pump on a 2003 Flexfuel 5.3L return fuel rail at 11psi with 75hp wet shot and was told that I dont have fueling issues by the tuner running consistent 11.4. Should I question that Information since you are running less boost and a dry shot? I have no scan software or gauges.
Dyno of Last Pull "Heat Soaked"
Dyno of Last Pull "Heat Soaked"
I also suggest that if you have specific questions on a setup instead of jacking another thread start one with your questions.