Best MLS HG. Tomei, ACL, Greddy, HKS; Why Did my head melt!?!

[bentvalves]

yea you need to not melt valley's in your head, and start by running the absolute least amount of boost you can while its being tuned, then turn it up in increments tuning each range of boost independently. Screw what I said about 15psi, start with 10 if you can. Who is tuning your car for you we are asking?

are you running off the wastegate spring, or using a boost controller? What psi spring is in the wastegate right now?

[boost_boy]

yea you need to not melt valley's in your head, and start by running the absolute least amount of boost you can while its being tuned, then turn it up in increments tuning each range of boost independently. Screw what I said about 15psi, start with 10 if you can. Who is tuning your car for you we are asking?

are you running off the wastegate spring, or using a boost controller? What psi spring is in the wastegate right now?

Whoever's tuning need to not be so conservative if they know what they're doing. Too much boost and a poorly tuned engine melted that head. Always the #3 cylinder because the same thing happened to a customer who let someone adjust his fuel trim to lean by 30% and ran 18psi of boost.

Dee

[niscort]

...and so was Nissans'. If it was ok for those 'dummys' to "waste"(?) their money (huge expense), time and effort for "no difference".... it should be "ok" for any of us mere mortals to, eh ? Reckon nissan R&D have a clue ?

For some reason it appears the JDM focus was on enhancing the weak low-end torque characteristics of the CA18DET - butterflys, 0.48 turbine housing, diff gearing

lots of first hand accounts of '4 vs 8 port' info in the early days of sxoc.I'm not talking about flow, port measurements or any of that foolishness, but the business end rather = what actually happens at the rear tires.Long story short... some replaced their tired 4 port with an 8 port motor. They preferred the performance of the 4, so they switched the head/intake only, to "regain their performance". Some tinkered with butterfly operation, others removed 'em etc.Been so long since reading feedback, a least that is the jist, from observation.

Enough 4 port combos detailed for review..... from kitten to monster. Choose one.I still don't know how their "brake hp" compares to our whp figures tho.

Luckily I got both. My interest lies only in comparing torque enhancement from butterfly tinkering... street driveability/T28(0.48)/16g etc.Once my tuning skills developed, 4 port gets the goodies/go-ahead to get wild.

On another note, I never trip over head flow numbers, like everyone praises hondas for example. Even with hi peak hp number, they get their arse waxed on the regular, any given day - so big fkn deal

So, some randoms in the uk seat of the pants, sorry, first hand experience is the basis for 'your' decision that the 4 port is better?

Your reference to the R&D of the Euro head by the dummies at nissan... rather a large asumption isnt it. Your point contridicts itself though, infering that Nissan must have actually wasted 'huge' time and effort coming up with the 8 port in the first place. Has the 4 port improved this weak low end condition it suffered???

Im sure there are differences.. Im far from convinced the one of them is researched and developed to give the effect of performance at the rear tyres. Surely such design and performance improvements would have made its way back into the Japanese market? but thats me assuming.

Mass opinion doesnt = truth. Im more than happy to see some proof that backs up your points.

OPmake sure you get the fuel rail with the sub manifold

[dash]

Quote »So, some randoms in the uk seat of the pants....[/quote] Yep, those "randoms" were the first detailed accounts documented I've encountered of anyone who actually ran both heads.A clever bunch of blokes who I'm sure (or assuming) had nothing better to do.I'm sorry, their efforts as well as 4-port experience are adequate for me.I certainly have no interest in convincing anyone. For what ? Do as u like

Quote »Your point contridicts itself though, infering that Nissan must have actually wasted 'huge' time and effort coming up with the 8 port in the first place. [/quote]No, you're twisting my words to make it sound like a contradiction.I clearly stated what 8-port/0.48 hsg/gearing... conveyed to me.then said why did nissan bother changing the head at all, for "no difference" ?

My point was, if nissan "wasted" so much money/time/effort on new castings for negligible performance difference..... who cares about the relatively tiny amount he/we/they do.

[mbmbmb23]

I was under the impression the whole butterfly mechanism added complexity (which increases cost), 2 significant reasons for Nissan to switch to a 4 port head....then ultimately the SR.

[dash]

I'd think the most economically feasible route would be to simply remove the plates & shaft, then cast the same mani without the holes. Retain the same intake & rail.I'm 'assuming' nissan could figure that out. Toyota 4AG, same deal..... new castings
Modified by dash at 4:09 AM 8/6/2009

[mbmbmb23]

I'd think the most economically feasible route would be to simply remove the plates & shaft, then cast the same mani without the holes. Retain the same intake & rail.I'm 'assuming' nissan could figure that out. Toyota 4AG, same deal..... new castings

Modified by dash at 4:09 AM 8/6/2009

Which head would be more expensive for Nissan to mill?

[bentvalves]

rebounded hard.

[boost_boy]

I was under the impression the whole butterfly mechanism added complexity (which increases cost), 2 significant reasons for Nissan to switch to a 4 port head....then ultimately the SR.

I like the way you think, my friend. This is exactly my thoughts, but I have a few other facts that I found with our beloved butterfly valves that most don't know. AS I stated somewhere before on this forum, that butterfly system works better when used on the naturally aspirated engines. The butterfly is not so useful on force induced variants.

The CA16DE was a wonderful protege and with the butterfly system correctly functioning, it was venerable enough to be a contender to the 4AGE. The CA18DE was created and it too was was venerable in stock form. But when you unplugged the butterfly valve system, it was a slug. I've had the CA DOHC series doing things nissan didn't intend it to do up to and including smoking the all new civic Sis for 1999 or 2000.

The butterfly valve system on the turbo engines are just extra trouble that can and will lead to serious problems as they get older. I know this because I've experienced enough issues from the system. I would go into detail on my theory, but what difference does it make; people are going to do what they want to do anyway. The 4 port head is cool in the fact that it has no butterfly valves, but I don't think it's a massive performance improver and is not really proven to better than the 8 port; or is it because it wasn't intended to be .

Conclusion/hypothesis: Maintenance and costs is the reason why nissan stopped the CAs in Japan and the U.S. as well as some other markets. The slight redesign of the heads were done only for the Euro market probably because their emission laws aren't as stringent. And remember that word "Emissions". So nissan probably said we'll let this motor model ride out a few more years before we comptely scrap it for something cheaper. Steel does cost hence the reason why your beloved SR was developed.

Dee

[float_6969]

AND to add to Dee's little tirade there, also keep in mind driving styles of different countries.

Think about Japan in general. It's an island. Has lots of ppl. Crowded. Taxes based on displacement. If you're building an engine for this place, it needs to be responsive, off the line (low end tq) yet have small displacement so ppl can pay the taxes on it. With these things in mind, Nissan, I would assume, would put a lot of R&D into developing a small displacement motor (CA16DE anybody?) that has a broad powerband and good low end torque. And I think Nissan did a great job. (This motor also lets you sell to the silly Americans of the 1980's who still have a love of big displacement motors and lots of low end grunt)

NOW, lets look at europe. Think autobahn. Think much more open. Think of countries that value top speed MUCH more than 0-60 or 1/4 mile times. Once again, displacement based tax. For this country I would want a small engine that makes good mid range power for sustained amounts of time. I would also be willing to give up low end torque to achieve this.

Remember, the 4 port head probably wasn't developed after the 8 port as an improvement. I believe that it was developed to cater to the different driving styles and requirement of different countries. (and I'm not sure, but I don't think Europe EVER got the 8 port head)

[ragenasian]

AND to add to Dee's little tirade there, also keep in mind driving styles of different countries.

Think about Japan in general. It's an island. Has lots of ppl. Crowded. Taxes based on displacement. If you're building an engine for this place, it needs to be responsive, off the line (low end tq) yet have small displacement so ppl can pay the taxes on it. With these things in mind, Nissan, I would assume, would put a lot of R&D into developing a small displacement motor (CA16DE anybody?) that has a broad powerband and good low end torque. And I think Nissan did a great job. (This motor also lets you sell to the silly Americans of the 1980's who still have a love of big displacement motors and lots of low end grunt)

NOW, lets look at europe. Think autobahn. Think much more open. Think of countries that value top speed MUCH more than 0-60 or 1/4 mile times. Once again, displacement based tax. For this country I would want a small engine that makes good mid range power for sustained amounts of time. I would also be willing to give up low end torque to achieve this.

Remember, the 4 port head probably wasn't developed after the 8 port as an improvement. I believe that it was developed to cater to the different driving styles and requirement of different countries. (and I'm not sure, but I don't think Europe EVER got the 8 port head)

I have been thinking the same thing for the longest time. The 4 ports here are in all years I have come across. My 89 had a 4 port, my 91 and also my 92 had a 4 port. So the 4 port has been around as long as the 8 port has. I have stripped a couple of 200sx's here and was surprised to find an 8 port. Don't know if it was original or somebody here trying to be a bit different.

[KEMP]

im using an HKS EBC, wastegate spring is about 5-7psi iirc.

so which head gasket do i use, give me your thoughts.

the car will have an EGT gauge before it starts again. and ill make sure to kep the temps under 1700* if not much lower.

but how do suppose i make sure this doesnt happen again? ive got plenty of fuel, and low timing...

[bentvalves]

get an OEM, or a felpro, or a steel gasket it doesnt really matter up to you. Dont go using a generic gasket "kit" headgasket, that is all.

We already told you how to keep it from happening, mingya.

who is tuning your sh*t -

[KEMP]

oem/felpro? im not sure about all of that, that sounds like a ticking time bomb to me...

[boost_boy]

oem/felpro? im not sure about all of that, that sounds like a ticking time bomb to me...

Just got through with a member's car that needed a head job because the timing belt snapped. So I just gave him one of my already machined heads, a composite h/g and new head bolts. In addition to this, I got his SR T25 rebuilt, added 750cc injectors, and of course he opted for a standalone to suit his needs. The stock T25 is running about 13psi of boost and the car runs really well. I can guarantee that that otherwise stock h/g will take an abusive 25+psi of boost if tuned correctly.

And the previous member's car I did two weeks ago is also running on the same gasket and was overboosting at or around 21psi and the gasket didn't let go. Though her car don't have the standalone, it still shows how tough those gaskets are. Detonation will kill any gasket at any given time, so don't be afraid to try those composite gaskets.

Dee

[bentvalves]

dont even answer this fool back anymore until he starts answering some of our questions. Dont answer our questions with questions, and stop being a f*cking stubborn goat.

[boost_boy]

dont even answer this fool back anymore until he starts answering some of our questions. Dont answer our questions with questions, and stop being a f*cking stubborn goat.

I said I was going to give-up if he doesn't answer questions especially about his tuner. That's oh-so important 'KEMP'. Help us help you or you may find yourself on yur own. Most people around here are struggling to get their cars to run,so it's going to be hard for them to help you.

Dee

[KEMP]

ok, sorry, i havent been able to get on lately.

my tuner, is a very well known and reliable tuner in the cincinnati area, and has tuned countless reliable, grea, fast cars over the years, he started young with his dad on card ars around age 16, then moved on to DSM/evo cars, then to 2jzgte(is300) cars, and countless cars in between.

he is now 30yrs old, and is by no means a young gun at tuning, he knows his stuff and tunes many cars.

[boost_boy]

ok, sorry, i havent been able to get on lately.

my tuner, is a very well known and reliable tuner in the cincinnati area, and has tuned countless reliable, grea, fast cars over the years, he started young with his dad on card ars around age 16, then moved on to DSM/evo cars, then to 2jzgte(is300) cars, and countless cars in between.

he is now 30yrs old, and is by no means a young gun at tuning, he knows his stuff and tunes many cars.

BUUUUUUUUUUUTTTTTT, has he ever tuned a CA? If yours is the 1st, then there's plnty to learn about what this little puppy like and don't like. It loves boost and $hits on bad tuning jobs.

Dee

[CakeEater]

The stock T25 is running about 13psi of boost and the car runs really well. Dee

Way off topic, I too am running an SR T25 at 13psi, but I have stock injectors and stock ecu....I just want to know if bigger injectors/ecu upgrades are needed? I was told before (by you I believe) that this is fine but I'm having second thoughts now that I see that you installed 750cc injectors and a standalone on your friends CA.

Any clarification would be awesome.P.S. I have no issues with the car, just want to be safe.

[boost_boy]

Way off topic, I too am running an SR T25 at 13psi, but I have stock injectors and stock ecu....I just want to know if bigger injectors/ecu upgrades are needed? I was told before (by you I believe) that this is fine but I'm having second thoughts now that I see that you installed 750cc injectors and a standalone on your friends CA.

Any clarification would be awesome.P.S. I have no issues with the car, just want to be safe.

13 psi on that turbo is the absolute max. If the performance is enough for you, then leave it be. But if you're hungry and want to see just how fun this little engine really is, an upgrade in the areas you mentioned is paramount. The problem with my friend/NICO member is the fact that he has all the goodies on the fuel and engine management side, but he too sports an SR T25 and it truly depreciates the money he spent on everything else. Once he changes the turbo, manifold and add an external wastegate, the car will be a sick one for me to tune.

Dee

[CakeEater]

Thats the feeling I had....It isnt enough for me so a T04E and standalone/injectors and an awesome tune are soon to be.

[KEMP]

you are absolutly right DEE, but, one thing i do not understand, is that my car was/is on super low timing maps, he set them low to be safe since it is his first CA to tune, and the boost and afr's were fine.

im still waiting on my injectors for checking, so im putting my money on a bad injector.

Dee, how familiar are you with nistune? and do you have the software?

If you would like to be an amzing help, i could even pay you, but i would like some sort of a base map that you would consider a "ready-to-tune map" so we have a better starting point this time, if you do not have the software, i could send you my pass key and maybe work something out.

Let me know. Thanks

[boost_boy]

you are absolutly right DEE, but, one thing i do not understand, is that my car was/is on super low timing maps, he set them low to be safe since it is his first CA to tune, and the boost and afr's were fine.

im still waiting on my injectors for checking, so im putting my money on a bad injector.

Dee, how familiar are you with nistune? and do you have the software?

If you would like to be an amzing help, i could even pay you, but i would like some sort of a base map that you would consider a "ready-to-tune map" so we have a better starting point this time, if you do not have the software, i could send you my pass key and maybe work something out.

Let me know. Thanks

I'm not too familiar with NISTUNE and the only member on here "21FOX21" has already wiped-out a motor, even though he got some good power. Once I started with standalones, I refuse to tune with anything else. The cleanliness of the installs, the amount factory garbage I get to eliminate, the fact that I have my own base programs for most injectors that makes initial start-up and driveabilty makes me not want to toy with anything else. Not trying to deter you from NISTUNE, but someone had better know what they are doing. As for your timing maps, I would love to take a look at what you're working to see how they classify timing parameters in their system. It would allow me to compare it to all my data from tuning different standalones to see if your tuner is outside of the CA timing boundaries.

Dee

[21FOX21]

I'm not too familiar with NISTUNE and thonly member on here "21FOX21" has already wiped-out a motor, even though he got some good power.

Dee

HAHAHA I had a rod bolt snap nothing to do with nistune.

[21FOX21]

If you would like to be an amzing help, i could even pay you, but i would like some sort of a base map that you would consider a "ready-to-tune map" so we have a better starting point this time, if you do not have the software, i could send you my pass key and maybe work something out.

Let me know. Thanks

You get a base map and there are settings for your maf and injector size that if you change them to what you have CORRECTLY you have a good base map.

[bentvalves]

you bent 3 rods slightly, and one rod got hella bent to the best of my knowledge.

[boost_boy]

HAHAHA I had a rod bolt snap nothing to do with nistune.

That's what you think..HAHA .Whoever told you different blew smoke up your tail to cover their behinds. You obviously made power by riding alot of timing. I know the motor well and know damn well what it takes to bend rods like that . So unless your engine drank water while under full load, your rods bending had plenty to do with the tuning of the NISTUNE system. And if you think the rods just mysteriously bent, try again .

Dee

[dhessian]

adding to the 4 port vs. 8 port debate earlier in this thread nobody mentioned that with the 8 port head fuel is only cooling/cleaning 4 valves instead of 8.

the dry valve phenom opens a whole new can of worms for the 8 vs 4 port debate and nissans reasoning behind designing the 4 port.

[21FOX21]

That's what you think..HAHA .Whoever told you different blew smoke up your tail to cover their behinds. You obviously made power by riding alot of timing. I know the motor well and know damn well what it takes to bend rods like that . So unless your engine drank water while under full load, your rods bending had plenty to do with the tuning of the NISTUNE system. And if you think the rods just mysteriously bent, try again .

Dee

One rod was hella bent from an injector being stuck open and motor still ran 11's and made 400 on the dyno after that. The other rods I am assuming bent when I was at a drift event drifting and somewhere in the 7000-8000 range my heater core blew and fried my ecu thus flooding my engine.