I have been running my car at around 10 psi on HRC stage 2 with internals. I can get the car to stop detonating. I try leaning it out, still does it. Richen it up still does it. My egts are all fine never go over 1450. My idle fuel pressure is 34 psi with vacum, I have 370cc injectors. The car runs great. I doesnt seem to detonate in first gear, but when I shift into the higher gears the load put on the engine just makes it detonate. I also have a Dis 2 installed but the settings are all like they came out of the box.I get the same results with the dis 2 bypassed. At full boost, 10 PSI, I get in the range of 80psi of fuel. I recently took the motor back apart due to leaky headgasket and the only cylinder that is knocking is #4. What do you guys suggest. I also forgot to mention I have the sfmu. Thanks in advance. I am also only around -3-4 percent on the hi side of my SAFC. Sorry for jumping around.

03 350Z
19"Volk GT-S, Greddy Twin Turbo, Greddy Exhaust
96 GS MT
S16g, Portfueler
Howell 2.2 Stroker

so if you got internals that would be stage 3 right? how do u know what # etc you are detox in? what octane are you using? do you have the msd dis2 normal? or the programmable kind?... if you have the normal i would retard around 4000-7-8000rpm about 5-10 degrees ..it depends what compression piston you got also...if u got the programmable u can program by rpm or boost etc... let us know



Michael 99gs
HRC Stage 2
http://www.dreamwater.net/purplebeast

Michael
99gs hrc stage 5000 SOLD...
2004 Honda Accord V6 (240 hp)stock
what other car should i buy?? hmmm
Car info & pictures at http://www.cardomain.com/memberpage/520269

I believe that the "knocks" you noticed are caused from the engine timing being advanced when under full boost. I had sufficient fuel before the pistons/rings gave, and I still ended up with a rebuilt. I couldn't think of anything else that could've caused the detonation, except that the ecu advanced timing under full load (I was boosting 10 psi).

Furthermore, I believe whoever has cam gears shouldn't advance the timing in the intake side. If anything else, it should probably be retarded; if n/a I know advancing the timing produced real hp numbers. Just as Michael GS mentioned, I think you should somehow datalog your car to find out at which point in the rpm bands or boost level the engine timing is advanced the most, then retard timing accordingly.

Even with sufficient fuel, a lot of guys are blowing pistons/rings; I believe engine timing has a lot to do with it, including my own engine.

Kon Chittavong
HRC: Stage IV | http://laoracer.homestead.com/mainpage.html

___________
Kon C

"Sometimes, a man has to do what a man has to do."

yeah Like I said I had to take the engine apart thus seeing the little indintations in the piston top of the # 4 piston. I went out and played with it after posting. I took my safc with corbin's boost pressure sensor, and set the throttle points at 0 and 20%. This made the safc's High %'s pertain to boosted situations only. So That I can adjust the percentages for when I enter boost. This actually seemed to help the car ran on the rich side and the detonation wasnt at a noticeable state. I couldn't hear it. So I am going to keep these settings. I am only at -5% on the high settings all the way through the RPM band. So I am not leaning out very much. I still have mor that I can go I am just hesitant to do so cause I dont want to get into the detonation problems again. I aslo only have the normal dis 2. And yes I am at stage 3. Sorry I just didnt say that. Well I will see how it goes. I also thought that you shouldnt have to retard the timing until 15 PSI or more. I need to get a datalogger.

03 350Z
19"Volk GT-S, Greddy Twin Turbo, Greddy Exhaust
96 GS MT
S16g, Portfueler
Howell 2.2 Stroker

what compression pistons do you have? if u can datalog to see how much advance your ecu is doing at wot etc you will have a idea how much to retard at certain rpms... i rather run a bit more fuel, and retard a bit more also then not enough fuel and to much advance will cause you to blow up sooner you may get more power with advancing but why chance it?... with a built engine i would throw it on a dyno and get it tuned the right way.. make sure the person tuning your car is good also, that always helps... i plan to with a rebuilt engine later..




Michael 99gs
HRC Stage 2
http://www.dreamwater.net/purplebeast

Michael
99gs hrc stage 5000 SOLD...
2004 Honda Accord V6 (240 hp)stock
what other car should i buy?? hmmm
Car info & pictures at http://www.cardomain.com/memberpage/520269

Hey everyone. I just signed up this morning, so this is my first post.

I have a 97 GS with the Stage II Hahn kit, Accel 415cc injectors, S-AFC, and some other little stuff. I am currently in the process of doing a FORCED rebuild because I blew my engine.....WAY too much pressure. I compressed and cracked the stock pistons in about 4 places on each one and pinched the rings so they no longer floated. I also blew the rear main seal at the same time. My guess is the timing advanced too much. I was watching my fuel and egt's instead of timing because I had just installed the new injectors.

My engine should be reassembled with the Howell bottom end kit (8.6:1 compression) in the next couple of weeks. When I do get it back, I need to find a way to retard timing. Does anyone know if the ITC (by Apexi I think) works with the 420a ECU? I know some of the 4g63 guys use it. If not, about how much do ignitions with timing retard cost?

Thanks,
Patrick

You are not your job.
You're not how much money you have in the bank.
You're not the car you drive.
You're not the contents of your wallet.
You're not your fu**ing post count.

97 Eclipse GS - *SOLD*
01 Audi A6 2.7T
01 YZF-R6

hey dude, well i know it was talked about before about the Apexi retaring deal, but im not sure if it will work with our cars. if i were you i i would choose from these 3 ignition depending on how much you want to spend and how you want to retard. 1st u can get the msd dis2 normal for about $300 and u can retard only by rpm, or the msd dis2 programable kind which u can retard by rpm or boost proportion with a labtop etc cost around $500-600, or the crane hidi2 i believe where u can retard by boost proportion only with a extra sensor around $500-600 also... if u want to do a search about turbos and u will be reading for hours... i would throw it on a dyno to get it tuned etc.. are you using a super afc to lean out those injecs? ..where are you located? how much are you spending on the rebuild labor etc? cool




Michael 99gs
HRC Stage 2
http://www.dreamwater.net/purplebeast

Michael
99gs hrc stage 5000 SOLD...
2004 Honda Accord V6 (240 hp)stock
what other car should i buy?? hmmm
Car info & pictures at http://www.cardomain.com/memberpage/520269

Yeah, I'm not sure if the Apexi ITC would work either. I figured it would be all over this bulletin board if it did work with our ECU's. One of my 4g63 friends suggested I ask.

I'll probably just go with the MSD dis2 for now. Money is tight after paying for all this rebuild stuff. Do you know if the dis2 has the stutterbox option??

I was using the S-AFC to lean out the larger injectors. I was actually out tuning it right after installing the injectors when I blew the pistons, rings, and rear main seal.

I live up in Colorado Springs at the car-choking altitude of ~6000ft. But I did manage to squeeze off a 15.3@91 at the track at 8psi before I blew the engine.

The total cost of my rebuild is going to be about $3000, $1800 for parts and $1200 labor. I got the Howell bottom end kit, ARP head studs, top end gasket set, and a bunch of other stuff like belts, water pump, new vacuum hoses, motor mount bracket, etc. And as far as engine work, I'm getting the block bored and honed, grind the crank, mill head, 3 angle valve job, and balance.

You are not your job.
You're not how much money you have in the bank.
You're not the car you drive.
You're not the contents of your wallet.
You're not your fu**ing post count.

97 Eclipse GS - *SOLD*
01 Audi A6 2.7T
01 YZF-R6

well for the msd dis2 you will need the tach adapters so u wont have any cel and to run it the right way... do you have a ob2 program to see you fuel curve why leaning it down with a super-afc? if not you should...cool




Michael 99gs
HRC Stage 2
http://www.dreamwater.net/purplebeast

Michael
99gs hrc stage 5000 SOLD...
2004 Honda Accord V6 (240 hp)stock
what other car should i buy?? hmmm
Car info & pictures at http://www.cardomain.com/memberpage/520269

Please explain to me how you have decided how much detonation you are getting by a simple drive? What is it you are doing that leads you to believe it is detonation?

05 Mazda RX-8
06 Lotus Elise

Hmmm...are you positive it's detonation at all?I run 18 Psi w/ 92 octane and never had problems.Try richening out your top rpm settings by a point or two.Either way good luck.

0k here is the situation. I am running rich when the pinging is occuring. The egts are fine. fuel pressure is fine.I know that it is detonation cause I recently took the head off for a headgasket and noticed the indintations. It only detonates some of the time. Other times it runs fine. it will acctually run noticably rich, when it is pinging, my throttle percentages on my SAFC go nuts. And I have the boost preasure sensor that corbin made. Maybe it is them map sensor. I will have to check it out. Also is it best to put the safc conections before or after the connections for the fuel cut defencer. TIA! Sorry for coming across irritated. I just am stumped. Everything looks fine. And it still pings. Today it ran fine. so it is something that is intermitant. This is why it may be the map sensor going bad.

03 350Z
19"Volk GT-S, Greddy Twin Turbo, Greddy Exhaust
96 GS MT
S16g, Portfueler
Howell 2.2 Stroker