no2 to spool turbo

[baadgn]

Tony. I hope you are grasping the significance of all this.

I'm not a theory kinda guy my testing is done on a dyno then proven at the track. Doing this way has not let me down yet.

 

[Alky V6]

On the topic of spooling turbo's with nitrous. A friend had a GN back around 1997 with a TA-49, stretch intercooler, ported heads. He used a 75 shot to spool the car at the street races but also used it for the entire pass. He didn't have to worry about the street racers burning him down because he could sit there barely above idle and spray it when the hands dropped. The car went 10.60's at 27psi. It would make 21psi off the hose, 27psi on it.

Yes. I've been playing with the idea of maybe using the AB injection nozzle down track, but that's a test that is low on the list right now.

 

[Alky V6]

I'm not a theory kinda guy my testing is done on a dyno then proven at the track. Doing this way has not let me down yet.

Some enjoy experimenting while others just like to play it safe. Nothing wrong with either choice.

I have to tell you, what's really exciting for me is when you test a theory out and it actually seems to work. That is very rewarding.

 

[Dusty Bradford]

For me, track data is the only one that matters. Because testing any other way is just testing......not proving. Sure it's more expensive and more work, but in the end it's the only way to know without a doubt.

 

[Alky V6]

For me, track data is the only one that matters. Because testing any other way is just testing......not proving. Sure it's more expensive and more work, but in the end it's the only way to know without a doubt.

I agree completely. All my testing and dialing in has been either in a stall at the shop or on the track. I have heard and read about how a tune can be different from engine dyno to chassis dyno to track.

 

[Bent6]

What I'm thinking is the turbo operates at a given pressure ratio. It's maxed out at 2:1. I have to wonder if the engine will make more power when your pressures are 20/40 rather than 35/70. The turbo should have to turn the same rpm to generate the hp, but the boost pressures are just lower on the larger flowing engine. When the exhaust valve is open and the piston is pushing against the pressure to get the exhaust out of the cylinder. There has to be hp in the fact the piston is pushing against 40psi rather than 70psi. It may be a wash if the reduction in bp makes power but the compressor side isn't in it's proper range. I built this motor for the 114mm but have to run a class locally with a 94mm so it's a good way to test the theory.

I'll buy into that idea as well. I changed to a better flowing set of S2 heads with a revised cam profile and have been quicker at lower boost than I went with the old combo with 5-7 psi more boost. Turbo and everything else is the same. I think the psi# required for peak flow with any given turbo is directly related to how much air you can efficiently push through the engine. After all, an engine is nothing more than an air pump.

 

[Quint]

Dusty, if your going to run say NOS right out of the hole and all the way down the track, you better have one hell of a tune on it, so not to hurt the engine. Conleys did that with Fear in the very beginning of testing and just couldnt get it right, to where the power levels needed to be and with out blowing plugs. Timing was off, everything just didnt work the way it was suppose to. We where also running BIG stuff 3 with issues. Now, if there is a way to let FAST run it, like it does on the t break, but all the way down, so we dont have to worry about spool time that would be awsome. With a 100 shot, I can spool Fear to about 12#'s in less then 2 sec, but you still have your waiting.

http://www.streetfire.net/video/buick-gn-stage-2-fear_164480.htm

 

[Dusty Bradford]

Dusty, if your going to run say NOS right out of the hole and all the way down the track, you better have one hell of a tune on it, so not to hurt the engine. Conleys did that with Fear in the very beginning of testing and just couldnt get it right, to where the power levels needed to be and with out blowing plugs. Timing was off, everything just didnt work the way it was suppose to. We where also running BIG stuff 3 with issues. Now, if there is a way to let FAST run it, like it does on the t break, but all the way down, so we dont have to worry about spool time that would be awsome. With a 100 shot, I can spool Fear to about 12#'s in less then 2 sec, but you still have your waiting.

Buick GN stage 2 Fear - Car Videos on StreetFire

I really see no need in running n2o all they way down the track unless the turbo is too small and your looking for extra power. The tune-up is much different. You can't jet it like it's a regular shot, you have to use more fuel jet than your average shot size would use. On his car, the 75 shot was over 150hp so it had to be jetted accordingly. He used 42# injectors......remember this was years ago so the fuel jet was also serving as a 7th injector. Yes, the tune-up was a piece of work. A nitrous tuner would look at the jetting and think

 

[Otto J]

LOL! In due time. I feel this latest engine build has stayed together as long as it has because of my very controlled strides forward.
My wife says, if I blow this one up,...?
I don't want to find out what the question mark means.

I was standing at the line at Las Vegas Motor Speedway when one of Don's experiements went wrong
Was a pretty loud KABOOM and lots of broken parts
I am sure that was a tough one to recover from

 

[antiquettype]

What I'm thinking is the turbo operates at a given pressure ratio. It's maxed out at 2:1. I have to wonder if the engine will make more power when your pressures are 20/40 rather than 35/70. The turbo should have to turn the same rpm to generate the hp, but the boost pressures are just lower on the larger flowing engine. When the exhaust valve is open and the piston is pushing against the pressure to get the exhaust out of the cylinder. There has to be hp in the fact the piston is pushing against 40psi rather than 70psi. It may be a wash if the reduction in bp makes power but the compressor side isn't in it's proper range. I built this motor for the 114mm but have to run a class locally with a 94mm so it's a good way to test the theory.

It's been proven lower bp makes power which is why Don's engine will exceed the power normally acheived with that head design.

I could be wrong on this but I believe you will make less power with the bigger inch motor than the 350. Of course I am no pro either. The exhaust housing is only going to flow so much air before the backpressure really gets out of control regardless of boost pressure. One thought, and just that, is that the small block combo might just be more efficient for the turbo. Like you said 35boost/70backpressure, you may only get 20boost/60backpressure because the motor flows more than the housing. Of course, you are probably going to a bigger housing since the bigger inch will spool better.

 

[Otto J]

I tune an XFI controller 2 stage nitrous car and you would **** if you saw the actual a/f ration I run

 

[Dusty Bradford]

I could be wrong on this but I believe you will make less power with the bigger inch motor than the 350. Of course I am no pro either. The exhaust housing is only going to flow so much air before the backpressure really gets out of control regardless of boost pressure. One thought, and just that, is that the small block combo might just be more efficient for the turbo. Like you said 35boost/70backpressure, you may only get 20boost/60backpressure because the motor flows more than the housing. Of course, you are probably going to a bigger housing since the bigger inch will spool better.

I ran a 1.0 and 1.32 on the small block, this motor has a 1.5.

I'm thinking 20psi/40bp is more realistic. So far the engine has ran 138 to the 1/8 on 11psi. I feel real confident I'll see at least 10mph from another 10psi of boost. The best the small block ran was 149 with a 400ci small block In testing, this bb engine has seen 21psi with only 24psi on the gate, and 14 on the gate nets 11psi.

 

[Alky V6]

I was standing at the line at Las Vegas Motor Speedway when one of Don's experiements went wrong
Was a pretty loud KABOOM and lots of broken parts
I am sure that was a tough one to recover from

It wasn't that bad. I was already thinking about the next combination before I got the car back into the trailer. You just can't let a blown engine stop you. You learn what you can from the experience and move on a little wiser.
Surprisingly, the kaboom had nothing to do with the nitrous system. It had to do with my inexperience with the alcohol. I was too lean for the static CR and boost level that happened. No pinging, just whack! It folded a rod. It also taught me what rods not to use.
The nitrous system has never really presented any problem, except the one time I tried to leave it on through the whole pass and I melted some electrodes. That was with the 200 shot. That was what did in the T70. :biggrin: Turbine wheels don't like flying porcelain.
I feel pretty lucky actually, that I've only blown two engines while learning to burn methanol from scratch with no help from anyone. There are some that have gone through a whole garage full of blocks to learn the fuel.

 

[Otto J]

It wasn't that bad. I was already thinking about the next combination before I got the car back into the trailer. You just can't let a blown engine stop you. You learn what you can from the experience and move on a little wiser.
Surprisingly, the kaboom had nothing to do with the nitrous system. It had to do with my inexperience with the alcohol. I was too lean for the static CR and boost level that happened. No pinging, just whack! It folded a rod. It also taught me what rods not to use.
The nitrous system has never really presented any problem, except the one time I tried to leave it on through the whole pass and I melted some electrodes. That was with the 200 shot. That was what did in the T70. :biggrin: Turbine wheels don't like flying porcelain.

I wasn't speculating it had anything to do with Nitrous,just remembered a loud bang.
Sounded wicked as hell in the burnout box!!!!

 

[Alky V6]

I wasn't speculating it had anything to do with Nitrous,just remembered a loud bang.
Sounded wicked as hell in the burnout box!!!!

I didn't think so, but the thread is about nitrous to spool, so I thought I'd throw that in so not to confuse others.

 

[Chevota]

Subscribed:smile:

 

[Alky V6]

Did anyone come up with an answer to my fuel consumption figures?
BSFC: 1.15
240 lbs/hr
Methanol: 6.7 lbs/gal
SG: .786

 

[HighPSI]

The 240#/hour figure is throwing me. Is that per/cylinder? Does it include both your electric and mechanical nozzles?

 

[Alky V6]

The 240#/hour figure is throwing me. Is that per/cylinder? Does it include both your electric and mechanical nozzles?

240 is per cylinder. It includes both systems under the delivery parameters I gave earlier. Keep in mind the mechanical nozzles were rated with gasoline, and they are constant flow.
I did the math myself a few times way back when, but it was time consuming. Especially, coming up with the amount supplied by the mechanical nozzles. The 240 number I came up with fit nicely with everything the sims were showing me.
When I ordered the mechanical nozzles from Kinsler, they were given all the parameters of my fuel system and were also given the hp target of 1200 bhp. The nozzle size that I'm presently using is the size Kinsler came up with to meet that target. As I've already stated many times, the fuel system is very close to being maxed out at this stage of tuning.

edit: The fuel delivery was checked by 3 different methods. First by me calculating it out on paper, the sim, and by Kinsler.

 

[Alky V6]

I could be off on the 1.15 BSFC. I checked my website and I have listed 1.18. I try to put accurate figures on the website, so go with the 1.18 BSFC.