I CANT BELIEVE IT HAPPENED AGAIN!!!

[HolyShiznit]

I have never, I mean NEVER had a problem with boost spiking. I HAVE A BD manifold. I dremeled and sanded and took out all the rough stuff that was left but it has NEVER spiked. Also I use a A'PEXi AVCR and a TRUE TiAL 38mm wastegate. I just recently ran it in 39 degree weather and only got a .02 bump in target boost pressure. I have no idea why you guys are getting such crazy problems.

[S14tat]

i'm running a blitz single solenoid ebc, and when its 40 degrees or lower, i would creep 3 psi. however i never tried turning it down. because i felt it would not make any difference.

the reason why i think that is becasue all a boost control basically do is block off the signal going to the wastegate. when the boost control is set in the off position, its already running the solenoid stuck open so all the signal can go to the wastegate. so basically if i tried to turn it down, it would be like me trying to make a 9 psi base spring 5 psi. i don't think its going to happen.

but anyways sorry for what happened. lets pray that you blew a headgasket and that your cylinders are gettin flooded ( the cause of it not wanting to start )

[GEO]

god dman your seeing 18psi ont eh stock engine?

[sunnys14]

how much boost can a stock HG handle? anyone think if i were to get a real tial wastegate would fix my problem? and what can i do to modify the manifold to prevent boost creep? dump the wastegate to the open??

[HolyShiznit]

Get a real TiAL wastegate. **** running a recirculated wastegate. Take off the manifold and go over it again. Smooth out the entry ports and make sure that the entry to the wastegate tube is smooth and no weld "boogers". Mine need to be die grinded down to make a smooth transition.

Lastly, get a boost controller, preferably a EBC. I searched around and found an AVCR on Honda-Tech brand new un opened for 220 dollars shipped. Good deals are out there. Best of luck.

[Jookmasta]

there was the issue right there.............u rerouted ur wastegate to ur dp u say. there is no mani i have heard of that CANNOT creep with the external wastegate rerouted. its not even an option from what ive seen as its like asking to have boost creep occur. this is y every other company out there producing KA mani's dont reroute the wastegate to the DP. creep creep creep.

yes if he was running an internal wastegate, he most likely wouldnt have creeped to that level.

so in short, yes if u had dumped to the atmosphere, u probably wouldnt have creeped that badly. im sure u understand whats going on when ur dumping to the atmosphere as compared to what is occuring when u reroute.........no need for me to get into that.

still tragic to hear ur loss. if ur gonna go to the SR, its personal choice. im sure ur motivation for pursuing the KA is wearing thin so i cant really blame u for ur thoughts. just think things thru as usual.

[WDRacing]

Hmmm....coming in late on this but...I'd start your next project by getting a Honda and keeping it stock. If your driving your car that you just rebuilt and the boost spikes to double what you have it set to and you don't stop...the problem isn't the KA, the wastegate or anything else. No offense....but let off the the throttle man.

Another KAT blown do to indescretion.

[klattr1]

so in short, yes if u had dumped to the atmosphere, u probably wouldnt have creeped that badly.

with my BD manifold, i had the wastegate dumped separately (not recirculated) and it would overboost 7-8 psi over the wastegate spring level towards redline (7200 rpms). but i had race gas and a fuel system to suppot that boost level...so i was safe, but still not controlled.

this is like the 5th case of overboosting ive seen with BD manifolds.

i can think of another KA-T manifold company that had the same problem in the past and porting the crap out of the manifold for better WG scavenging helped the problem.

[huguetpj]

Sunny:What kind of spike was it? Was it a real spike or more of a creep?

Ryan:Same questions? From how you describe it (... toward redline) I think it's creep not spike.

Anyway, my point is... if sunny did SPIKE (/\) and not CREEP (__--¯¯) it maybe was not the manifold at all. In my case I blew one engine because my EBC was incorrectly setup -- I'm still saying it was caused by an incorrect translation of the instructions to English and I'm sticking to my story . In sunny's case I'm leaning toward the knock off WG staying shut... or maybe a signal line popping of or being constraint by something (kinked?).

And by the way... sunny, if you go the SR route and change to a cheap WG, you can probably spike too and the stock SR will not take 17PSI either. I even detonated at 13PSI (due to boost spike) in my KA with only forged pistons (meaning stock everything else including injection) and walked away. When it detonated at 19PSI I was screwed

[klattr1]

Ryan:Same questions? From how you describe it (... toward redline) I think it's creep not spike.

i was talking about a creep. spikes usually occur near peak TQ (3500-4500 rpms depending on turbo size) whereas creeping is exactly that (progressive towards redline).

[huguetpj]

Thought so... so my question to sunny still remains...

[sunnys14]

in 2nd gear, boost held at 8psi till about 4500rpm and BOOM jumped instantly to 17 psi. it went up so fast it i couldnt even comprehend that it happened. i let off the throttle as soon as i found out but it was too late

[sunnys14]

Hmmm....coming in late on this but...I'd start your next project by getting a Honda and keeping it stock. If your driving your car that you just rebuilt and the boost spikes to double what you have it set to and you don't stop...the problem isn't the KA, the wastegate or anything else. No offense....but let off the the throttle man.

Another KAT blown do to indescretion.

hey buddy, the problem wasnt that i kept on the throttle. i was watchin the boost gauge the whole time and by the boost gauge jumped up, i let off but it was too late. im pretty sure that anyone that is on their 3rd motor would be careful as fu*k as to try not and blow it up.

[klattr1]

i let off but it was too late.

prolly too late because of your injector size.

[sunnys14]

prolly too late because of your injector size.

haha ofcourse! 370cc's can barely handle 10psi! 17psi? thats way over the limit...

[WDRacing]

I wasn't tryin to get you all worked up, the Honda thing was a joke. I've done the same thing you did and I've had ALOT of experience with the initial shakedown problems. The boost gauge in my car is direckty in my line of site. Being the most importan thing for me on the first run, aside from datalogging the AFR's. Which is why I always start so rich she barely boosts.

The initial post made it sound like you stayed in it because it felt so good, which is true when you run lean, she'll pull wicked hard. I was just expressing in my usual, pretty obnoxious, way to be WAY more careful. Especially in the beginning. Learning the way you did sux balls...

Sorry U thought I was being a d!ck. I'll buy ya a beer at a meet if we run into each other.

WD

[nissanfanatic]

Quote »s14 sr20det + megan racing manifold, 14 psi = around 250whp?[/quote]isn't quite

Quote »stock manifold, stock boost, stock turbo...[/quote]

[nissanfanatic]

I agree with WDracing from a slightly different POV.

Always when you first get a boosted car running, roll in very slowly a few times first. From my personal fcuk ups (ie forgetting to put wastegate line back on), it is a very good idea...

Bust out the compression tester to get some info feedback.

[Titan]

haha ofcourse! 370cc's can barely handle 10psi! 17psi? thats way over the limit...

There is no such thing as being able to handle XX psi. Pressure and airflow is what matters.

7 psi on a T25 is NOT the same as 7 psi on a say a straight T4.

We're talking dynamic pressure here, which has the component of air flow (i.e. CFM).

This is why you see air tools not only rated for pressure, but also a certain amount of CFM in order for them to function at full capacity.

[WDRacing]

Thats why the AFR, EGT and Boost gauge are so important. Especialy in the beginning. EGT not so much, but I like to see whats going on temp wise as I drive her around.

[sunnys14]

WD dont worry about it, its all good. i was just trying to expressed that i was so shocked when it pulled 17psi that i didnt even know what happened. it happened so fast... i left off real quick but by the time i did, white smoke was already pouring from my exhaust.

[sunnys14]

There is no such thing as being able to handle XX psi. Pressure and airflow is what matters.

7 psi on a T25 is NOT the same as 7 psi on a say a straight T4.

We're talking dynamic pressure here, which has the component of air flow (i.e. CFM).

This is why you see air tools not only rated for pressure, but also a certain amount of CFM in order for them to function at full capacity.

yeah, i meant 370cc's can barely handle 10psi from my t04e. my mistake for not explaining it more clearly.

[WDRacing]

Well, you boosted 9 psi over the 8 you wanted, figuring the average 10 whp per lb of boost, thats an extra 90whp you jumped up to. Possibly more do to the lean mix and advanced timing. Which will make a ton of power right up till it starts to detonate.

WD

[huguetpj]

Well sunny... if that is the case, I'm leaning toward something else being the culprit instead of the manifold. Spikes that fast rarely (never) occur due to manifold design, or lack there of. Anyway, I would double check the signal line for kinks, punctures or any other problem in getting the signal to the WG.

[Jookmasta]

i still say the reroute of wastegate was the culprit.............

[sunnys14]

so i should run open wastegate and get a REAL tial 38mm. the new question is about the stock headgasket. i already have an OEM headgasket thats been sitting in my room for over a month now... how much PSI has the stock headgasket been proven to hold? 14psi? or should i wait and get a cometic gasket? cometic has a 2 week wait time for headgaskets and i cannot wait that long.

[klattr1]

if you arent going to resurface the head to a mirror finish, then stick with OEM type headgasket.

so pretty much just a blown HG is the problem? have u compression tested it as well?

[sunnys14]

can the studdering at high RPMs be detonation?! im gonna pull the head off anyways and examine the pistons while im at it. i plan to keep the intake manifold on the head while im pulling the head. im just going to undo the 2 heater hoses and vacuum lines. is there any specific directions on pulling off the head? i know i have to take off teh front cover and stuff... but what else?

[klattr1]

the stuttering in higher rpms could have been your spark blowing out (typically happens in colder weather-denser air = more HP). lowering plug gap will fix that.

obv. pull all of the exhaust side stuff off the head. then pull the intake manifold off the head but dont detach anything. literally pull it off the head and leave it sitting to the side in the engine bay. otherwise you'll hate life later when you are fighting those heater hoses. go ahead and set the motor at TDC so that it will be there when you are setting everything else back up (timing chain, gear alignment and such). take the cam gears off, then all the cam bearing caps in correct order. then pull the cams out and then loosen and remove all the head bolts IN THE CORRECT FSM ORDER. take off idler sprocket, upper timing chain. after that, the head is ready to come off.

after head is off, examine where the HG is blown. it might have little pinholes in certain spots. KEEP UP WITH THE DOWELS that guide the head onto the block.

clean everything REALLY good. dont gouge anything.

if you didnt overheat badly or anything, you are prolly fine to use stock-type headgasket on non-resurfaced head. but i usually have mine checked for level and pressure checked.

put new headgasket on. make sure the orange fire-ring thing is wheres its supposed to be. put dowels back in the block (pinch em in and tap few times). guide the head back on.

then start assembling. use this JWT guide and FSM for cam alignment and such:

http://jimwolftechnology.com/w...E.PDF

make sure to use proper torquing for everything and tighten the head bolts IN THE CORRECT ORDER. its VERY critical. put RTV where it needs to be as well.

be careful with the idler sprocket. its easy to screw up the threads in the head where that goes. make sure it goes in straight.
Modified by klattr1 at 1:05 AM 12/9/2005

[Jookmasta]

and yes, dump to atmosphere with the next external wastegate.............