11.1:1 + 6psi = x

[TrunkMonkey]

OOOOOOK

...honda motors boost in bolt on form...not true? Honda owners who turno up the boost on a honda have to re-tune the e-manage for the hgher boost. They will not turn up in BOLT ON FORM...if they do...they may only last 2-3 months...weve got idiots here in columbia that have tried and failed at doing it

from this post, it sounds like a greddy bolt on kit is the only turbo kit you've seen for hondas. regardless of the kit, you have to retune for more boost, period. turning up the boost doesn't kill an engine, but lack of tuning does.

The bottome end of a honda:No..i said what i meant. Hondas have a forged bottom end. Even if they do make impressive hp with boost...they are also more inclined to make horsepower at higer rpms..theyre honduhs. My mistake....i though i saw a post were someone made a refernece to a honda with a 400hp stock bottom ended car.

*scratches head* what? *scratches head again*

The t04e 60 trim is more effieceint thatn my 50 trim? at 6 lbs of boost?! Please. Look at the maps. And waht does a t04e 60 trim have to do with a turbine anyway? 60trim? 60 trim what???compressor? When you say t04e 60 trim...you should be more specific when talking about efficiency. Is your turbo a t04e 60 trim compressor? what turbine size housing? what stage or trim turbine wheel? Ceramic wheels? Standard wheels? The 50 trim t04e compressor is a much broader efficiancy range than the 60 trim. at 6lb pounds of boost you wont even be close to the efficiency range of a 60trim wheel.

please reread through this thread. ca240 asked me why i opted for a straight t04e instead of t3/t4 hybrid. i gave him my answer. YOU came in with the notion that i was using an inefficent turbine to cover up possible problems. when you said inefficent turbine, i assumed you meant turbo (i apologize for assuming), thus the reason i mentioned the to4e 60 trim.

as far as the 50 trim vs. 6o trim, i'm not sure what numbers you're using to plot you're maps, but the 60 trim owns the 50.

Who cares about the ringlands of the cars you are reffereing to? They are also running 9.5:1..not 11:1 CR. People have a hard enough time getting a car tuned to run with no detonation on 9.5...much less 11. And you are using SOHC pistons. When tearing it down...why not just throw in somme forged 9.5:1 and be done with it? Taking a risk on pistons that, regardless of popular belief, do not stand up well to boost over time. Yes..there are a some that do just fine, but they are not commonplace at 260+ hp, and are not running 11:1 cr. Ringlands on ka pistons suck...and thats the truth.

running boost on 9.5:1 is hard? ...please don't say that out loud.

i mentioned the cars that i did because they're running in much more extreme conditions than me. these guys compete in 100+ degree daily/track conditions at high boost levels on a stock engine. i'm sure they've experience detonation on several occasions. the engines held up fine. i don't do any type of competition racing (occassional street), autocross, or anything. south carolina heat (while hot as hell) does not compare to arizona's.

The final static compression with 11:1...

It has been increasingly common on the 240sx.org forums to see peolpe who have never built a turbo motor up to come up with new an inventive ideas. However these ideas are fed by regurgitation of info they have read and/or misinterpreted, and hold as gospel. You cannot just sit and crunch numbers to come up with a final CR and determine a power figure given x amount of boost. Then these ideas are backed by nothing but thoery, and a poor attempt to outwit someone by trying to have a verbal contest on the forums, by just spitting out info here and there. Its gets old, but hey, to each his own. I BUILD 240's. Ive gone through the same thought process as everyone else. And i have tried to do the thing that i see others trying to do....i just try and help em out.by heading them off at the pass before they get into a money pit or a point they cant get past.

final compression, boost compression, and effective compression...

i didn't make this up. i've heard all three of these terms used for the same thing. in a nutshell, it's the compression that your engine is at during operation under boost. do some research.

i didn't figure it out to come up any power figures for whatever amount of boost, i needed to see if i was going into an area that hasn't been touched. 11.1:1 with 6psi is the same as running 10 psi on stock compression. in other words, i'm not putting any more strain on the internals than what hasn't already been done.

-demetrius

[C-Kwik]

Projex240: what's the diffeerence if HP is made at 8000 RPM or 5000 RPM? HP is still HP.

Secondly, why are you so focused on using forged parts? The KA pistons, are strong enough to take quite a bit of additional load. It's not strong enough to resist too much detonation, be even forged parts will fail when exposed to sustained detonation. The point is tune it so it does not detonate and pistons will probably be the last thing you need to worry about.

Lastly, have you built a high CR turbo KA? I think it's poor argument to say you are basing your opinions on your experience, if you haven't actually have experience in this particular topic.

Demetrius: The T04E-50 is more efficient with the KA. The peak efficiency island is 78% as opposed to the 60 trim's 76%. Secondly, the 78% island covers a large part of the KA's powerband. Not to mention the 76% island is huge and should cover the powerband and then some. At 6 psi though, neither turbo will see the peak efficiency, but the 50 trim still has better efficiency down low. The only thing the 60 trim does better in is the shaft speed is lower at any given point. But it's rather marginal. Both turbos will feel similar in power. Small differences in efficiency make very marginal changes in power. But I find the 50 trim is marginally a better match.

[TrunkMonkey]

Demetrius: The T04E-50 is more efficient with the KA. The peak efficiency island is 78% as opposed to the 60 trim's 76%. Secondly, the 78% island covers a large part of the KA's powerband. Not to mention the 76% island is huge and should cover the powerband and then some. At 6 psi though, neither turbo will see the peak efficiency, but the 50 trim still has better efficiency down low. The only thing the 60 trim does better in is the shaft speed is lower at any given point. But it's rather marginal. Both turbos will feel similar in power. Small differences in efficiency make very marginal changes in power. But I find the 50 trim is marginally a better match.

i've been clawing over this for a couple of hours and i found out what the problem is. we're looking at two different 60 trim maps.

for example...





different sites that list compressor maps have one or the other map displayed (most of them have the second map). the only one i've ever seen is the second one. this makes a big difference when trying to pick a compressor. which is correct?

-demetrius

[C-Kwik]

That's a real good questions since the 2nd map would put peak efficiency closer to 80%. The peak island isn't marked, but I would guess it's 79-80 at least. I've been going off turbonetic's compressor maps, which is the 1st one. At least it matches the one in their catalog. The site the 2nd one came off of seems to deal with Turbonetics turbos so it's hard to say for sure. Definitely a good find. Unfortunately, we need to figure out which one is right...

[14.5drift]

The new celicas are succesfully being turbo charged and they also have a 11.5 cr. And for project240sx, I have met a guy who runs 450 fwhp on a b18 type r, ON STOCK INTERNALS. Runs low 11's and is daily driven. He has also a vw gti holding down 450 all wheel power, on stock internals, daily driven. Both cars are over a year old, and are very high compression motors. The key is tuning.

[dareo]

The key sure is tuning you got that one nailed. But even the slightest errors that go on in a boosted high cr engine can break stuff. The more you push it the more perfect you have to have the tuning.

[Projex240]

I have met a guy who had a 450 hp stock internal type r too...it was fast as nutz...until it melted a whole in the piston. Not detonation.....that would have simply shattered or broken the piston...it melted a whole straight hrouhg it. And hes no slouch on tuning either. The difference is that 5000 rpms HP is more effective in street cars that dont have the short gearing that is better suited for high rpm hp. 8000 rpm hp is peaky, which is not as fast as a a car with the same rwhp that is making its power at 5000-redline at 7200. By the time a 8000 rpms car gets to its peaky powerband, ive been at my peak power for 2200 rpms and singin my way to about 3 cars in the lead in 4th. hp is not hp....it also bepends on where you powerband lies. If you have a car that is really godd at mid-range, then you dont want a high rpm killer with a tiny eff.island...just like you said to demcj. Plus, I dont car what kind of tuning you have....9.5:1 can cause problems with detonation. Im not saying it will all the time...but yes...it can.

Also...the honda tuning on nottom end is mostly done with a standalone type hondata. I dont exactly compare the tuning abilities of a hondata to JWT's ecu. Hondata would own JWT if it were into nissans. my main point is...if you are going to tear down a motor to rebuild it....why use crappy factory pistons? detonation kills ringlands...yes i know that, lets move on. But also so does the added stress of a boosted atmospheric load.

[JPRempe]

Just so ya know though....I do think that higher than 9:1 with boost is cool as hell. But it has to be done right. Using weak assed factory internals with 11:1 with a plug and play JWT and an afc is outright dumb, even for low boost/power. Forged internals with a standalone is the only way id throw money into a project like that.but hey...its your dough.Just for ****s and giggles...lets go through this.Motor parts:Pistons - about 150 if they are cheapmore so around 250-300 if you want a good set or new.Machine work and rebuild-1000...if its less...watch out unless youll do it yourself.JWT ecu - 550 from stillen--call phil tell him i said wattup.afc 2- 330 afc is just as good for about 260 but doesnt have a much fine-tunability.turbo--do it cheap 1700 with good parts and cutting corners. but more likely about 2500 for a good kit.clutch to take the power - 300better run an external wastegate- you cant afford to have ANY boost creep- low boost on big turbos means creepy boost is out for you!!!!250gauges and a techtom for monitoring a knock- around 300so roughly(very roughly)5600 bucks----for 225+/- ?! Its just not worth it bro.Be different and put a 2jz in it or something like that, but dont just waste money.

Don't put a Toyota motor in it...slap in a VQ30/35 and be done with it...

[C-Kwik]

I have met a guy who had a 450 hp stock internal type r too...it was fast as nutz...until it melted a whole in the piston. Not detonation.....that would have simply shattered or broken the piston...it melted a whole straight hrouhg it. And hes no slouch on tuning either. The difference is that 5000 rpms HP is more effective in street cars that dont have the short gearing that is better suited for high rpm hp. 8000 rpm hp is peaky, which is not as fast as a a car with the same rwhp that is making its power at 5000-redline at 7200. By the time a 8000 rpms car gets to its peaky powerband, ive been at my peak power for 2200 rpms and singin my way to about 3 cars in the lead in 4th. hp is not hp....it also bepends on where you powerband lies. If you have a car that is really godd at mid-range, then you dont want a high rpm killer with a tiny eff.island...just like you said to demcj. Plus, I dont car what kind of tuning you have....9.5:1 can cause problems with detonation. Im not saying it will all the time...but yes...it can.

Also...the honda tuning on nottom end is mostly done with a standalone type hondata. I dont exactly compare the tuning abilities of a hondata to JWT's ecu. Hondata would own JWT if it were into nissans. my main point is...if you are going to tear down a motor to rebuild it....why use crappy factory pistons? detonation kills ringlands...yes i know that, lets move on. But also so does the added stress of a boosted atmospheric load.

Are you sure it wasn't detonation? The main reason detonation kills pitsons is because the heat goes up significantly. I've seen the effects of detonation on a Supra. Part of the piston was melted and another part had chipped off. Melting parts can easily occur due to detonation.

HP is HP. Period. Of course a transmission geared incorrectly for a motor will cause poor overall performance. This does apply to motors that don't rev high as well.

And when did I ever say anything about a tiny efficiency island having to do with a good mid-range or high RPM motor. As far as I'm concerned, it does not matter. The turbo has no idea what RPM you are running. It only cares for airflow. A broad peak efficiency island is desirable with any turbo. But for best results, it should also be at or near peak efficiency through a motor's powerband at the given boost level.

I think you have to care what kind of tuning is done. Detonation can occur at any compression ratio if tuned incorrectly. Too much timing or even too low an octane of fuel at even say 7:1 CR can still cause detonation? Tuning will be a big part of controlling detontation in ANY motor.

Not sure how the Hondata vs JWT argument has any merit here. Has nothing to do with the internals. And as far as internals, why go forged? If a cast part is up to the task, then I see nothing wrong with using a cast part. Forged parts have a bigger margin for error, but if you know what you are doing and perhaps are willing to take the risk, then I say go for it. It's an issue of opportunity cost. And it's not the same for everyone. You're opinions are certainly welcome, but are not the final word. There are many ways to approach this. The one who is going through with it has the ultimate decision making power. I see nothing wrong with Demetrius trying this out. Tehre is always a level of risk, when modding your car for more power. He is planning on approaching it a different way. And I'm sure the first person to turbo a KA had many concerns as well. Yet now that it's become more common to see turbo KA's and there is a lot of documentation out there to help foresee and troubleshoot problem areas, it's much less of a risk to most people.

I think you have brought up many concerns that he will need to face with a high CR turbo motor, but I also think you put too much weight on them. 10 years ago, many would have cringed at the thought of running 15 psi on a stock 9.5 CR KA. But there are several that are doing it successfully. TY from FA is running about 17 psi. He has a built motor ready to drop in, but is intent on seeing how much the KA can handle. His stock KA is still running strong.

And lastly, find me one KA ringland failure that wasn't attributed to detonation. I've seen the stock KA ringlands. They are nowhere near as thin as the ones I see on some of the ULEV/LEV vehicles. And many of these motors are being boosted and have relatively high CR's.

[TrunkMonkey]

That's a real good questions since the 2nd map would put peak efficiency closer to 80%. The peak island isn't marked, but I would guess it's 79-80 at least. I've been going off turbonetic's compressor maps, which is the 1st one. At least it matches the one in their catalog. The site the 2nd one came off of seems to deal with Turbonetics turbos so it's hard to say for sure. Definitely a good find. Unfortunately, we need to figure out which one is right...

i never thought of this before, but do you know of any other turbonetics compressors that have a peak efficiency of more than 78%? that may not mean anything, but if the first map is the one that's in their catalog, then that's the one i'm going to assume is correct.

-demetrius

[C-Kwik]

The T88 has a peak island of 80%.

[ArticDragon192]

You crazy, but I like. Let us know how it goes.