Jason.
What exactly do you mean by "low" knock??
If you're making that sort of power and you hear even the slightest ping then you may as well head home to pull the thing apart!!!
If you pull it apart & find broken apex seals then there's your answer.
RE gards
Jon

 

Peter,
If i am not mistaken the DIY kit was showing around 12.0 and the dyno wideband was showing about 11.7 at the tailpipe.
When the stutter happened, there was nothing else audible happening. Lots of smoke, as it had been doing all night.

At first, i thought it had just fouled a spark plug due to running rich and having back to back pulls. Jason and Nocab replaced the plugs in the car with the previous plugs, and still no start.

Jason, I hope we can figure something out today!
Good Luck!

Joe

 

Jason sorry to hear about the car. I really think you need to have someone on the dyno and watching the fuel pressure gauge while your on the dyno. Black smoke at the upper rpms makes me believe that the fuel pump couldnt keep up. Just my thoughts. I will be up there today after the Buckeyes stomp some ***.
Go Bucks

 

Yea we could have tuned it better at 12 lbs, but we did one run as a base run before working up the boost. 12lb timing numbers were conservative. I have to look but I think from 10lbs up timing was at 15degrees with a 12 split. After 2 runs we dropped the split to 8 to see the HP differences.

When we got to 1bar we really didnt push the boost much past that. I would have to look at the logs for charge temp but It was cold out and we had a fan on the intercooler. I was also running 10.5 race plugs.

2 weeks ago we tuned on the street up to 16lbs and the car had been running good. We really didnt touch the fuel lastnight because it looked good.

We were using the DIY and it was probably to close to the turbo, but we also had another in the tailpipe and the numbers were similar.

Jason

 

Compression check is done and its blown. Only 2000 miles and time for a new one.

 

Oh ****. Sorry man.

 

I'm conseding that my stock motor is weak. The most I got out of it with the stock twins and all the bolt ons was 319rwhp@1bar before I bolted the GT35/40 up.

Dyno run today was a measly 387rwhp @ 17psi. Guess it will make my fresh pineapple motor feel all that much better next week!

Dyno numbers on the new motor as soon as I get it broken in! We plan to do the swap this coming week.

k

PS Sorry for the confusion, I didn't think to look who was logged in...this is nocab72.

 

We really did not change many parameters last night. mainly small testing in split (not investigatory, rather we knew what to expect and when to turn back) and upping the boost. Four cells around 5-6200rpm were modified less than +/- 3% fuel. No other fuel changes.

The car was tuned for >12psi. Had not been tuned for "cruising" yet.

The NTK O2 sensor was fresh and for 6 runs we had within .2 AFR of the NTK in the tailpipe (DynoJet's).

Low knock meant nothing out of the ordinary. Some of you guys go off on too little. All the knock readings were within 'norms' for THAT car. I have plenty of data supporting this, but the last 15 seconds of the last run were not datalogged. INTERFACE NOT RESPONDING! Argh! Funny thing was that this imformation showed on the screen and we were able to verify knock, and boost levels as being "okay" W3rd.

 

Did you guys run 15 deg advance on the 1 bar and above runs? I forgot to ask what type of fuel also?

I know my engine is very sensitive to even small ignition changes at maximum power range, it became a hell of alot more so after I did my race ported exhaust and maximum street port as it made my maximum VE happen in the range of 6500 to 7200 rpm, hence I had to be carefull with the amount of timing even with WI into the engine.

In the street cars I set up with that type of power I tend to shoot for an a/f in the range of 10.8 to 11.2:1 when running on "pump gas" alone. This is based on the fuel here in Australia though ? And with the timing, depending on the engine 12 deg is my safe zone (conservative) for charge temps below 52 deg C, charge temps above 52 deg C I set the ECU to pull 2 to 2.5 deg advance out above 165 kPa (absolute)...so in hotter conditions around 10 deg total advance. I have made good power with these settings, try em out on your next engine, I know it's better to start of safe then work your way up from there till your happy then wind things back a bit for the ever important "saftey margin"

 

Right around 14 degrees starting after 10psi and after the torque peak. Then to 12 over 15psi. Nothing dangerous with the split, either. Petrol was 94 octane.

Sounds good on the cross over point at 52C. Sounds smart!

We tuned to 11.4, but ended up with richer than that (was a hot night tuning). Ran at about 10.9-11.1.

 

What about an ignition amplifyer? Could the spark have just not been strong enough? I've heard of people breaking up on the top end without an ignition amp, and backing out of the dyno run...

Kyle

P.S. sorry if you already have one.

 

We're all using the HKS TwinPower. Makes a proven and consistent difference.

 

Rice, what boost are you talking about when you say 12°? Also you run 0° split correct?

Thanks,
Eric.

 

Yes I run 0 split, I run 12 deg advance @ boost pressures above 15 psi, I do not just like talking about boost as many different engines depending on VE and other variables will make VERY different chamber pressures at that boost pressure.

It is realy a function of engine power (something we can all understand) for a given engine capacity and operating variable (ambient conditions and fuel specification), for a 2.6lt making over 500 bhp on pump gas to cover a range of operating conditions I would run no more than 12deg of advance (@ boost pressure over 1 bar), just to be safe ........... I hate rebuilding engines : ) when I do not need too

In regards to my split : ) I do not have accuracy issues, because I only use two ignition channels out for front & rear rotor (wasted spark method for leading) on my ECU, so the L & T are triggered together regardless if the ECU is a little bit out (inaccurate)

 

BTW: I saw more power @ 8degree's split than 6 so I stayed @ 8. Someday I'll get brave and try 2 or 4, but since I didn't gain (actually lost) going from 8 to 6, I backed it off. Maybe 6 is a dead spot and there are 30more hp below...

k

 

Fellow Aussie AJC13B found a similar thing, or his tunner did. I know that different engines respond to different setting, also I think there is much merit in the ignition resolution of the ECU when running multiple ignition channels per rotor, this could maybe cause fluctuations in the L & T split that could cost power and @ worse cause engine failure ?

It is interesting to hear different experiences, the engineering behind close split shows that combustion happens faster and the pressure rise in the cahmber is quicker and higher than any other method, which should result in more power technically becasue Power is a function of mean pressure and engine speed. Anyway that is a topic covered else where so enough said.

When is the new engine coming ?

 

The engine is somewhere between Salt Lake City, UT (when I got a status on it yesterday) and Memphis, TN where it will be handed off the the freight company actually deliverying it to my door.

We pulled the engine last night (3 hours labor), not bad for my first engine pull, had good help though...

Tonight I'll be pulling all the accessories off, expecting the engine Friday.

k

 

...I was just lying on my back and I still hurt myself

 

damn, i wish that motor would fall off the truck here. i need to get my car going again. i need the time first

 

I know everyone has thier own opinion on ignition amps but i've heard when you get into the mid 400's rwhp the HKS isnt really good enough anymore.

Hopefully its just a busted seal and it didnt ruin any housings!!!!!!

Also, Baddog, I think you mentioned a a/f of 10.7-11.2 or something like that but Jason was saying around 11.7. Which a/f were you guys using at the time it broke up. If you were running a a/f of say 10.7 its going to take a lot of spark to combust the fuel properly at those power levels.

STEPHEN

 

The max we saw under boost and high rpm was 11.7. The range was what the averages showed.

I think we lost a part of the ignition system under load and flooded under deceleration.