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Old 10-12-2006, 02:32 PM   #226
Matt Monson
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I would like to know how 154ft/lbs gets translated to over 200? Are you listing the Zzyzx car or ZTH???

And Migo, I have headwork. I just don't have a built block...
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Old 10-12-2006, 02:41 PM   #227
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Quote:
Originally Posted by Matt Monson View Post
I would like to know how 154ft/lbs gets translated to over 200? Are you listing the Zzyzx car or ZTH???

And Migo, I have headwork. I just don't have a built block...
Oh okay. The graph didn't seem to make sense with such a contrast, so I figured you didn't have headwork in that plot.
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Old 10-12-2006, 02:42 PM   #228
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Oh okay. The graph didn't seem to make sense with such a contrast, so I figured you didn't have headwork in that plot.
The graph makes no sense at all based upon the published numbers in the ZTH articles...
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Old 10-12-2006, 03:41 PM   #229
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Zzyzx, sorry assumed that was being refered to as the "Z" car. Lol, I'm just messing stuff up.

Fixed....again.

Don't mind me. It's apparently not my day.

Is there a dyno graph printed of the Zth car?
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Old 10-12-2006, 04:30 PM   #230
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You know, I haven't seen a scanned graph of it around here. I have the issue at home, and Ryan pm'd me the numbers a while back. But I don't know of a digital copy...
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Old 10-12-2006, 05:02 PM   #231
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I should really get a supscription, bought a couple copies. It seems to be a nice little magazine.

That Zzyzx car is a monster. Isn't that close to STI territory? Or at least built WRX(2.0L)/2.5L WRX/XT territory? Pumping out 200 ft-lb torque basically all the way through. That'd be fun to drive...if it managed to retain drivability for daily usage. I'm sure the 108oct. race gas doesn't help that situation. .can't exactly pick that up at your local gas station.
http://zzyzxmotorsports.com/news/300hpna
http://zzyzxmotorsports.com/news/300hpnamods
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Old 10-12-2006, 05:50 PM   #232
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Old 10-12-2006, 06:17 PM   #233
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anyone try the STi head on the RS block? I was just thinking of the electronic valve tuning and possible jumped CR.

This sort of swap has been done with the KA24 nissan motor. My buddy put the ka24 dohc head on the sohc block and jumped the compression to 11:1. He was a wacko with that motor. Thats as technical as i know.

All i know is, it didn't make that much more power because the difference between the dohc and sohc was maybe 5-10hp?

When i think valve tuning, i think honda. There are a lot of k24/k20 swaps going around the honda community. They talk about adding ITR this and ITR that. Its amazing what cams do to an N/A motor. Crower claims 35-50hp increase with their aggressive cam profiles.
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Old 10-12-2006, 06:22 PM   #234
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Zth car added.
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Old 10-12-2006, 11:53 PM   #235
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I looked at the post you made. About the 300hp N/A car. It uses the same sohc head without eletronic valve tuning. Thats why i asked about the STi head.

108 octane + head work + tuning = 300hp? Weird how simple that sounds.
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Old 10-12-2006, 11:54 PM   #236
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Double post;.
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Old 10-13-2006, 01:35 AM   #237
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Matt:
I was talking about looking at OUR plot and comparing our baseline to our latest pull, not yours to ours... If you look at ours and ours alone, you can see that not only have we increased peak HP/TQ but shifted the entire graph up.

To replicate what we have done would take $$$ and as some of you have pointed out it really seems like we are spending alot to get where we are.

The fact of the matter is, and this goes for turbo cars too, you can only make big jumps in HP and have it economical up to a point, like say I/H/E Cams, EMS. And that will get you a hefty amount of power over stock, say 30whp just as a nice round number.

To get another 10-20whp you might have to spend twice again what you spent on all your previous parts. to get another 10whp, if you can is more money so by them time you are done you might have spent two to three times you initial investment to get a measly 50whp.

I think our numbers are pretty conservative and we have done some track testing that I think bears that out... but you have to wait for the next issue for that. The dynapack is a cruel mistress and does not lend itself to dyno queens. I have seen this particular dyno read lower than other dynos, however, I cannot say with any degree of certainty what that margin might be.

It is interesting to note that we have experienced the same "dip" at ~3000rpm that shows up in Matt's graph and it does translate on the street as a hesitation, I wonder if this is just a function of the design of the heads or what.

As far as the ZZyzx car I really want to know HOW you guys are getting there. More revs? C16? Plastic manifold? Let's just say for the hell of it that our dynos read in the same neighborhood, you have 70 more whp with it would seem a very similar motor? Is there 70 horse in cams and fuel? That might be the "no duh" of the year, but if you can shoot me an email on some hints I would appreciate it.
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Old 10-13-2006, 09:33 AM   #238
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The dip at 3000rpm seems to be an ECU thing. I don't know. You see it on a lot of graphs and could very well be an aftereffect of the intake tune or what-not. I just know I-Speed was commenting on it say a year, year and a half back when they were creating their RS flash. They mentioned the strange dip at 3000rpm that shouldn't be there and they actually tuned it out through programming. Their initial plot of their work was basically the stock curve with that tuned out to make a flat curve all the way through. They eventually pulled the whole band up 5-10ft-lb, and the dip never came back. I don't know. With the flash and realworld driving, there is no hesiation there, just pulls right through.

I know the stock ECU was very finicky moving in and out of open/close loop. Simple throttle moduation confused the thing, and winding through the rpms always had spots of hesitation as it switched modes, translating in well defined changes in power delivery. After the flash, this open/close loop transition is unnoticable, and throttle modulate simply transmits to instant response. I personally have a lot of blame for the stock ECU tuning for a lot of things our cars seem to do. Still, our intake, heads, cams, headers, etc. are all tuned certain ways and influence the powerband in a summed and hopefully not contradicting manner.
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Old 10-13-2006, 11:09 AM   #239
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Quote:
Originally Posted by MeanEditor View Post
Matt,

I would like to compare our power delivery with yours. My bet is that we have more area under the entire curve and that our torque delivery is more constant. This is a function of our bottom end and maybe the port work.
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Originally Posted by MeanEditor View Post
Matt:
I was talking about looking at OUR plot and comparing our baseline to our latest pull, not yours to ours... If you look at ours and ours alone, you can see that not only have we increased peak HP/TQ but shifted the entire graph up.

To replicate what we have done would take $$$ and as some of you have pointed out it really seems like we are spending alot to get where we are.
Care to explain further?

My car and your car use the exact same cams. BOTH of our cars have shifted the power in a very similar fashion. You claim that the dyno you use is a cruel mistress, but the Dyno Dynamics that I run on is also known for reading very low. If it was about claiming the higher number, I would go get on the Mustang Dyno we have down in Denver. I've been on Cobb's Mustang dyno (before the headwork) and my car delivers more than 20 more whp on that dyno when comparing my car with identical mods. I reviewed your dyno plots before I ever opened my mouth. I have followed the whole ZTH build and know how to extrapolate the numbers from your results to have a very solid idea of where your car stands.

But for the benefit of the readers, I will go over a little bit of it. It does pose a bit of a challenge because you guys never got a true baseline number for the car. But, with just a TWE header, it got 132ft/lb and 113.9hp. Now that does leave us guessing a little bit, but it would be fair to say that the headers got you guys about a dozen HP, so, for comparison purposes we can say your baseline was AROUND 102whp. That's already reading higher than the dyno I use reads for stock RS's. Ours is usually at 95 or 96whp, with the strongest stock car we've ever seen around here hitting 100whp. But all in all, one could say that the dynos are pretty comparable, delivering pretty similar results.

So, if we take that assumption for granted (which I am sure someone will choose to argue with) then when it's all said and done, your car is making about 10 more whp than mine. And as we all say in the article and in reviewing your plots, a good chunk of that was from getting a good tune. As such, I stand my my assessment that for the vast majority of the population, spending the money on a built block like that is a waste of money. It brings almost no additional power to the table. The tune is worth it's weight in gold and is a very cost effective power adder. But unless someone has a cam that is more aggressive than Cobb's Spicy cam, having a bottom end that revs to 8000rpms is just so much mental masturbation and not truly contributing anything to the project.

Now, I would also like to mention that I am pretty sure that my port work is more aggressive. I have asked Ryan to post the bench flow number on ZTH's portwork a couple of times, but have never gotten an answer. But based on the text of the article, it suggests that the work is VERY mild. Mine is not. I am at 267cfm intake, and 208cfm exhaust at 28" @ .450" of lift. This is up from 250cfm intake and 162cfm exhaust, with most of the gain obviously being on poorest flowing exhaust port that everyone talks about...


Of course, once you guys strap NOS onto the car, that bottom end will earn it's keep, but you also cease to be NA at that point. If you stick around, I think you will find that some of us are pretty hardcore in our purism regarding NA. Any compromise of that purity and we don't veiw the vehicle through the same eyes. Anyone can make power with a bottle or a snailshell. What made ZTH interesting to many of us was that it was NA.

Now, Cobb currently has an employee project car that will be experimenting with both a new cam profile and a new header design. I will be watching this as it progresses. If a more aggressive off the shelf cam comes to market, you can bet I will head back to the shop and build a block to support that. But my bottom line point stands, and that is that on most anything but a racecar, a built bottom end is not money spent wisely on an NA build with our current options for cams...

Last edited by Matt Monson; 10-13-2006 at 11:20 AM.
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Old 10-13-2006, 12:11 PM   #240
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Quote:
Originally Posted by Matt Monson View Post
Of course, once you guys strap NOS onto the car, that bottom end will earn it's keep, but you also cease to be NA at that point. If you stick around, I think you will find that some of us are pretty hardcore in our purism regarding NA. Any compromise of that purity and we don't veiw the vehicle through the same eyes. Anyone can make power with a bottle or a snailshell. What made ZTH interesting to many of us was that it was NA.
Big +1 on this paragraph.

I'd really like to see SubieSport toy with the cam profile and even show some real technical know-how and design their own for the high-revving bottom end. They've reached the limits of the off-the-shelf performance envelope, now it's time to innovate.
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Old 10-13-2006, 01:30 PM   #241
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Quote:
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But my bottom line point stands, and that is that on most anything but a racecar, a built bottom end is not money spent wisely on an NA build with our current options for cams...
I just rolled 176,000 miles on my stock shortblock earlier this week, and abut 90,000 miles of that has been with the car making roughly 40hp more than stock at the wheels. Countless auto-x runs, drag strip passes, and 20 or 25 open track days are included in that 90,000mi. So I'm with Matt - I think the built lower end is a BIG unnecessary expense for a N/A car.

The engine will be coming out of the car this winter I think, so maybe I'll discover that the shortblock is toast and is only running by the grace of God. But for now it takes a lickin' and keeps on tickin', so I'm gonna keep pounding on it. (Shenandoah Circuit at Summit Point tomorrow .)

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Old 10-13-2006, 05:15 PM   #242
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Of course, once you guys strap NOS onto the car, that bottom end will earn it's keep, but you also cease to be NA at that point.
To me, that doesn't make any logical sense. It's like saying once you run C16, your motor isn't NA all of the sudden, which we know is rubbish.

I do know where you're coming from, however. You want to see a "pure" NA build. But that's the magic of NO2, if you dont want to use it, you can always disable it and the car runs exactly as it did in the "non NO2" state. Want more than NA will get? Hit the fun switch. I really don't see why this "spoils" the build. It adds cheap and safe power. Isn't that what we're all after here? In the end more aggressive cams and a better manifold wont care if we also have a bottle attached or not -- if it's set up right.

R
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Old 10-13-2006, 06:03 PM   #243
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Ryan,
You are right, power is power and we all love power. But No2 is NOT NA power. That's not really open to debate. It doesn't make ZTH any less cool of a car. It just means that there a bunch of us who will lose interest in it because it's no longer NA. It doesn't "spoil" the build, but unless you guys push the envelope of streetable NA power further, it's just not new territory, and I won't buy a magazine to read about how the car made another 40whp by hooking up a bottle. I eagerly awaited every new issue that updated the NA portion of ZTH's build.

There's also a large crowd of folks who will be giddy that your car is on laughing gas. And other people will buy the magazine to read about it. That's the beauty of this place and the world at large. There's room for all of us, but when threads about nitrous get started in the NA forum, the moderators generally put them where they belong, in AFI...
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Old 10-13-2006, 07:00 PM   #244
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In drag racing No2 is considered a power adder. There are three power adders.
1. Turbo
2. supercharger/blower
3. No2

N/A uses none of those.

Period.
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Old 10-14-2006, 07:56 AM   #245
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I think now is a good time to throw out BSFC. There's a handful of good threads out there about it, and finding one of them and linking it in the opening post would be worthwhile. What Shiv showed years ago was that BSFC limits the Ej25 to about 185chp. In abesence of headwork and/or cams that significantly change the nature of the engine, that's the limit. You guys can argue all day long about exhaust and intake etc. etc. but you aren't going to get much more than 185chp...
I found this to be very interesting. I didn't know what the hell you were talking about. Well while reading some threads on the fourms tonight I came across some other guys talking about BSFC. Very interesting. I do'nt know enough about the fuel system in the RS to figure everything out. Maybe you could answer how large the injectors are, what the fuel pressure is at the fuel rail. If you could answer those q's then that would give us a lot to work with I think.

Am I wrong in assuming that with larger injectors BSFC will rise, thus making it possible to create more power with larger injectors and a tune? Sounds too simple.

Here is a link that gives some formulas to help you calculate the amount of fuel one should need to certain hp numbers.

http://www.rceng.com/technical.htm
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Old 10-14-2006, 10:53 AM   #246
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The thing is, without more air coming in to match that fuel you won't make more power. You need both. That's why cams change the BSFC and allow bigger gains, because they open the valves longer and higher letting more air through. Head and IM porting also do the same. In the end it's the amount of air you can get into and back out of the engine that determines your BSFC. You can always find fuel system upgrades to match that airflow.

It's also why boost has such a massive impact on power. Now you're *forcing* more air through.
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Old 10-14-2006, 02:42 PM   #247
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Is a car with nitrous considered a "part-time" NA car, then?
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Old 10-14-2006, 03:56 PM   #248
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Is a car with nitrous considered a "part-time" NA car, then?
I believe in the classic street/bracket racing terminology of "run what ya brung", a car with the bottle in the trunk is a car on spray, whether or not yer usin' it.
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Old 10-16-2006, 11:26 AM   #249
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In addition to the nitrous topic, it's a temporary power adder, thus not important in my book, regardless of how much power it can add. If a nitrous car can hit X amount of horsepower and a turbo/supercharged car can hit the same level, and a NA car can hit about 50whp less, the nitrous car would still come in last place if you were to take all four cars around Laguna Seca for 1 lap.
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Old 10-16-2006, 10:43 PM   #250
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Quote:
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In addition to the nitrous topic, it's a temporary power adder, thus not important in my book, regardless of how much power it can add. If a nitrous car can hit X amount of horsepower and a turbo/supercharged car can hit the same level, and a NA car can hit about 50whp less, the nitrous car would still come in last place if you were to take all four cars around Laguna Seca for 1 lap.
How so? n02 can be activated in a number of ways. Like at WOT, so you can use it up the back straight and the front staight or maybe the spurt from turn 3-4 and then between 5-6 to the kink leading up to the back straight...

Basically you can use it like an on/off switch or you can trigger it based on a set of parameters like TPS, RPM etc. It's not just for drag racing. Although it will be interesting to see how it behaves in a road course setting which is where we will use it.

But like I have said before, getting NA power is just as expensive as turbo power, it just gives fewer returns so finding another 50whp in our engine is going to be rather expensive.

We are currently turbocharging our 97 LGT and that is proving to be rather expensive, we will just have more power at the end of the day with this car and to make more power, we can dump in C16 and turn up the boost, that I think is the biggest difference.
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