9.19 @ 145.5 For The Alky Car

[GNBRETT]

Have you had any issues that you could attribute to using the N20. Meaning, has anything broke as a result of the nitrous that you know of? I just wonder why more people don't opt for it to spool larger turbos. Seems like it works pretty well for you. Btw, will you need to change your converter with more N20 flowing thru and going faster?

 

[Alky V6]

Have you had any issues that you could attribute to using the N20. Meaning, has anything broke as a result of the nitrous that you know of? I just wonder why more people don't opt for it to spool larger turbos. Seems like it works pretty well for you. Btw, will you need to change your converter with more N20 flowing thru and going faster?

The only time I did damage to the engine that was directly attributed to the nitrous was when I tried leaving it on for the entire run rather than turning it off at 18 psi. The ground electrodes melted, broke some spark plug porcelain, and the porcelain went through the turbine wheel and damaged it. Obviously, the porcelain broke because of the fuel going into preignition. I was lucky that no serious damage happened to the engine. This one incident is not to say that it wouldn't be possible to leave a 200 shot on for the whole run, it's just that I decided to try it on the spur of the moment and my tuneup was not right for it. In fact, the tuneup was way off, looking back on it.
I'm surprised more people haven't tried it too. I think the Buick crowd, as a whole, tend to be on the conservative side. There isn't much progressive thinking here. Now if you look at the import turbocharger crowd, I don't think there is much that isn't common place with them now. They were going with alcohol fuel and nitrous assist long ago. Heck, VP designed and named a gasoline blend after them. The Buick crowd is way behind the times.

The converter I'm using now was purposely made very tight for the planned use of 1,000+ HP. I would only expect the T/C would work better for me at a higher HP level. I like to see around a 1,000 rpm drop between shifts. Right now I'm seeing about 1,600 to 1,750 rpm drop depending on what shift your talking about, and it changes depending on the shift point rpm. Less of a rpm drop, as small as 1,000 rpm, if I shift at 6,000 rather than 7,400. With a high HP level, that number will lessen. Hopefully, ending up to be at my target of 1,000 rpm drop between shifts with a shift point of 7,400 rpm. I know that it seems to be the fad to go very tight with the T/C to cause as much of a drop in rpm after a shift as possible, but that can hurt you if the rpm drops into a rpm range where cylinder pressure is at the thin edge. Something to think about when you're picking your torque converter.

 

[GNBRETT]

Kool, thanx. Yea it seems like every little ricer on the planet uses N20 and it works fine for them. Both 4 and 6 cylinders. I guess with all the fail-safes N20 setups offer these days its a wonder more don't use it. I know I certainly will with my next build.

 

[Alky V6]

If the time is taken to study the properties of nitrous oxide, a simple and effective system can be put together without a controller. A controller would make fine tuning very nice. Don't get me wrong. Just realize that it can be done without one. I use simple relays, micro switches and pressure switches with the most complicated electronic device being a simple delay box.

It is very important to keep in mind the durability limitations of todays solenoids when choosing a controller/system combination.

I would also suggest to anyone that is considering building a turbo engine with the thought of using nitrous assist, to carefully consider every specification of the engine, and powertrain for that matter, with nitrous use at the forefront of your decision. It will open up a vast number of choices to you. The biggest point being, you will no longer have your hands tied by the dreaded turbo spool-up dilemma.

 

[Alky V6]

One thing that may surprise many of you is just how little nitrous ends up being consumed, even with a 190 shot system. I used one bottle for 8 runs over the WCN. I'll have to weigh it and report how many lbs I used. I waste more nitrous during the purging process than I use up during the actual run. I've gone several events on one bottle. This is with using the nitrous for spooling assist only. If you keep the gas on for the entire run, the story is going to be different.

For effective and consistent runs you'll want to change out your bottle for a fresh one after you've used about 5 lbs. with a 10 lbs. bottle.

 

[lazaris]

You were right on with your assesment. After studying the datalogs, I found that the boost was declining with engine rpm. It would peak to 29-30 psi by around 5600 rpm and ramp down to 25-26 psi by shift point (7400). After the shift, boost would be back up and then trail off again to 25-26 psi at the upper end, crossing the finish line at 25-26 psi. That would explain the low mph. I think the pure T76 is just at its limit, running out of breath. Otto, why did you get rid of the 4580 so fast?

Don I wouldnt say its out of breath just yet. Its more likely the BP pushing open the gate at that rpm. Do you run BP gauge?

 

[Alky V6]

That's a very good point. I don't have a BP gauge, but I have thought about the possibility you've mentioned. I have been tightening the wastegate in the recent past, as I've been coming up on the tuneup and boost level. You may be on to something. I just switched the springs in the wastegate to stronger ones before the WCN meet, and I think they are still on the weak side for a 30 psi boost target. There's still room left on the tension adjustment. The next time out with the car I'll plan on tightening up the wastegate to see if the MAP trace changes at all. If it does, I'll be looking at installing the stiffer spring combination. Thanks for bringing that up. There are a few other things I'm going to try this coming weekend and tightening up the wastegate did slip my mind. I'll also work on installing a BP gauge. There's a pre-turbo O2 sensor bung plug that I can tap into to install it. Good thinking! Thanks!

 

[bison]

Don, you arent running a closed loop wastegate system on there? I assumed you were holding it shut with nitrogen.

 

[lazaris]

That's a very good point. I don't have a BP gauge, but I have thought about the possibility you've mentioned. I have been tightening the wastegate in the recent past, as I've been coming up on the tuneup and boost level. You may be on to something. I just switched the springs in the wastegate to stronger ones before the WCN meet, and I think they are still on the weak side for a 30 psi boost target. There's still room left on the tension adjustment. The next time out with the car I'll plan on tightening up the wastegate to see if the MAP trace changes at all. If it does, I'll be looking at installing the stiffer spring combination. Thanks for bringing that up. There are a few other things I'm going to try this coming weekend and tightening up the wastegate did slip my mind. I'll also work on installing a BP gauge. There's a pre-turbo O2 sensor bung plug that I can tap into to install it. Good thinking! Thanks!

Your welcome. It might take a bit more than just a few lb increase on the spring if the BP is really high. What size exh housing and turbine wheel are you using? The BP gauge will tell the story if its enough. Also the flow of your wastegate will come into play.

 

[Alky V6]

Don, you arent running a closed loop wastegate system on there? I assumed you were holding it shut with nitrogen.

Now that the present engine has a good base tune and since my previous engine met an early demise just as I was getting a good base tune on it, I'm just now dealing with these other tuning issues. This is new territory for me. I'm aware of the CO2 or nitrogen option, just haven't come to the point where I felt I needed to go that route. I'm really trying to keep the rest of this project as simple as possible. I guess we'll see.

It is a closed loop system, but it's using manifold pressure. Not an auxiliary pressure source. Being that it's a 60mm valve, it's probably more likely that this is my problem. Is this a very likely possibility?

 

[Alky V6]

Your welcome. It might take a bit more than just a few lb increase on the spring if the BP is really high. What size exh housing and turbine wheel are you using? The BP gauge will tell the story if its enough. Also the flow of your wastegate will come into play.

It's a T4 housing with a Q trim wheel. The wastegate is a HKS GTII 60mm with a 2" dedicated pipe running straight out to the side of the car.

The wastegate comes with a spring package that gives you the option to run different combinations depending on the target boost level you're shooting for. I'm working from light to heavy to make sure I don't run into any spiking problem. There is one step further I can go with the spring package to strengthen the wastegate. I want to slowly work the tension screw tighter and see how the MAP trace changes. If the trace starts to level off and not drop, without any sign of boost spiking, I'll be a happy camper. If the trace changes and starts to level off with just slight dropping of manifold pressure, and I run out of adjuster, then I'll debate whether or not to go with the heavier spring package. That depending on any sign of boost spiking. I'm very cautious of boost spiking, since that is what killed the last engine. If I do end up going to the heavier spring package, the adjuster will be backed all the way off and worked tighter as needed.

You guys have to realize something. That weekend at the WCN was THE weekend that the tuneup just started to come around for me. There is still a lot of fine tuning to be done.

 

[lazaris]

It's a T4 housing with a Q trim wheel. The wastegate is a HKS GTII 60mm with a 2" dedicated pipe running straight out to the side of the car.

The wastegate comes with a spring package that gives you the option to run different combinations depending on the target boost level you're shooting for. I'm working from light to heavy to make sure I don't run into any spiking problem. There is one step further I can go with the spring package to strengthen the wastegate. I want to slowly work the tension screw tighter and see how the MAP trace changes. If the trace starts to level off and not drop, without any sign of boost spiking, I'll be a happy camper. If the trace changes and starts to level off with just slight dropping of manifold pressure, and I run out of adjuster, then I'll debate whether or not to go with the heavier spring package. That depending on any sign of boost spiking. I'm very cautious of boost spiking, since that is what killed the last engine. If I do end up going to the heavier spring package, the adjuster will be backed all the way off and worked tighter as needed.

You guys have to realize something. That weekend at the WCN was THE weekend that the tuneup just started to come around for me. There is still a lot of fine tuning to be done.

Your wastegate size is good. You may be ready to step up in exh wheel size depending what size your exh housing is. Again the BP gauge will tell you what it needs.

 

[Alky V6]

Your wastegate size is good. You may be ready to step up in exh wheel size depending what size your exh housing is. Again the BP gauge will tell you what it needs.

The turbo is an old school non-super Turbonetics T76 single ball bearing with a T4 turbine housing and Q trim turbine wheel. The a/r is .82 on the turbine housing.

That's a good suggestion. I'll get that BP gauge set up. I'm curous too. I'll report the findings.

 

[bison]

It is a closed loop system, but it's using manifold pressure. Not an auxiliary pressure source. Being that it's a 60mm valve, it's probably more likely that this is my problem. Is this a very likely possibility?

I think the exhaust wheel is too small myself. From your description it sure seems that way. Boost is trailing off at higher rpm. That exhaust wheel is a dinosaur compared to what is available today. Maybe a .96 a/r and 25hp more N2O would help the wheel a little.

 

[Alky V6]

I think the exhaust wheel is too small myself. From your description it sure seems that way. Boost is trailing off at higher rpm. That exhaust wheel is a dinosaur compared to what is available today. Maybe a .96 a/r and 25hp more N2O would help the wheel a little.

I actually have a .96 housing I can throw on it. I'm going to do a little more testing with the .82 housing this weekend, first. Thanks for the advice.

 

[edv2]

Great job! That is awesome!I was thinking of the nitrous for mine to get out of the hole better(still running stock trans and converter)Let me know what you think! Thanx,
ED

 

[Alky V6]

Great job! That is awesome!I was thinking of the nitrous for mine to get out of the hole better(still running stock trans and converter)Let me know what you think! Thanx,
ED

I think it would work great. Make sure it activates only at WOT and over 2400 rpm to start with. Start with a 50 shot.

 

[edv2]

WOW! That thing is baaad aaasss!Do you have any still pics of the engine setup? I'd really like to check that out! Who did all the Fabrication work?Thanx,
ED

 

[Alky V6]

Thanks edv2. My website has some vids and slide shows. drwtransmission.com. I did all the fabrication.

Lazaris, you were right about the wastegate. I checked out the spring combo I have been using in the wastegate and it was a set meant to control boost between 88.3 - 127.5 kPa. My latest target has been around 200 kPa boost. I installed the next stiffer spring combo. It's meant to control boost between 127.5 - 166.7 kPa. I screwed the tension adjuster in about 1/4 travel with this spring combo. The boost now fluctuates between 29 to 30 psi boost throughout the upper rpm range. Unfortunately, the air today was worse than the air at the WCN so no new records. Just about matched what was done at WCN though, with the bad air. My best run today was .1 second off my best ever at the WCN. I lost that .1 on the 60 ft. I did set a new best mph for the car today. 118.009 in the 1/8 mile. Tomorrow, I'm going to max the boost out at 31 psi and see what happens. My boost controller and ECM aren't meant to go over 31 so this will be the ceiling for me.

I think the tires have just about reached their traction limit too. First gear's a pretty wild ride. A lot of steering.

 

[Chevota]

Congrats on the new best 1/8 Don. Your IAT's seem high for your liquid IC/meth combo. Mine are consistently in the 115-120deg range at the end of a run. Circulating the water during the run would definately help your inlet temps and get that 2/10's!

Good luck!

Scott Wile