[Eric_Oz_S2]

Never seen anything like 90C intake temps on my car - even on 35C days on the track. That is really high.

Partial Post: Please Login or Register to read the full post.

[flash]

not at all. most modern cars have much higher intake temps than we might like to see. think about it. what temp is the engine bay? most cars get their intake source from less than optimal locations.



normally aspirated, in stock trim, our cars usually see between 60C and 70C. the airbox mod lowers that quite a bit. the SC kit normally sees lower temps than that too, but i am not afraid at all of temps as high as 80C. after that, it can get dicey, depending on the condition of the motor and such, but still it has not shown to be a problem all by itself in any application so far.



that being said, lower temps are better, safer, and a whole lot easier to get power out of, especially on older less sophisticated systems like ours.



this particular incident was not likely heat related. it looks like detonation, but not as a result of heat. it looks like it just ran out of fuel, which is entirely possible if there is ANYTHING less than perfect in the fuel delivery system, and certainly coupled with sustained high rpms.



i considered lowering the redline, but i wanted to leave over-rev room, and since the power peak was just over 6k, leaving it stock seemed like a good idea. i just never anticipated anybody doing this (except maybe me). lol - i guess i'll have to add some warnings.

Partial Post: Please Login or Register to read the full post.

[Eric_Oz_S2]

Well that must be a peculiarity of the 968, as i have an open element intake air temp sensor connected to a datalogger and the intake temps certainly creep up when idling but never more than 20C over ambient. I have never seen more than 50C on the track and only slightly above 50C on the dyno on a hot day. These temps are measured at the throttle body.



I think you are probably right about the lack of fuel at the top end as the primary cause.



Perhaps you could also develop a d1r knock sensor kit for the 968?

Partial Post: Please Login or Register to read the full post.

[flash]

the car comes with knock sensors. no need to reinvent the wheel.



what i am surprised about is that we have not seen codes thrown on this incident. the hammer should have shown it lit up like a xmas tree.

Partial Post: Please Login or Register to read the full post.

[DaveN]

Certainly no ! light when it happened. If the DME stores data without power (?) then I can dump this the next time the car lights up. Probably in the spring though after the new block and the re-re has happened <img src="/forum/images/smilies/968/sad.png" class="smilie" alt="" />

Partial Post: Please Login or Register to read the full post.

[flash]

you won't get the exclamation light with knock sensor stuff



the DME does indeed store the codes. it dumps them when you disconnect it though.

Partial Post: Please Login or Register to read the full post.

[gbarrier]

Would water injection do this engine any good?

Partial Post: Please Login or Register to read the full post.

[Cloud9...68]

Water, I doubt it. Nitrous, on the other hand... <img src="/forum/images/smilies/968/cool.png" class="smilie" alt="" />

Partial Post: Please Login or Register to read the full post.

[KRAG50]

In the old days, at least for piston driven fighter air craft, water inject was use for emergency power, I'm not sure how it worked, maybe it raised compression ratios.

Partial Post: Please Login or Register to read the full post.

[Eric_Oz_S2]

[quote name='flash' timestamp='1344179428' post='130536']

the car comes with knock sensors. no need to reinvent the wheel.



what i am surprised about is that we have not seen codes thrown on this incident. the hammer should have shown it lit up like a xmas tree.

[/quote]

Woops - meant knock counter kit.



Here's a link to one I made for the S2:



http://forums.pelicanparts.com/porsche-9...hread.html

Partial Post: Please Login or Register to read the full post.

[tamathumper]

Just read that whole thread, very educative, a fun video, and a great build. Thank you.

Partial Post: Please Login or Register to read the full post.

[DaveN]

Cloud - Nitrous! <img src="/forum/images/smilies/968/ohmy.png" class="smilie" alt="" /> Best see "Thy Rod no longer Comforts Me" thread cuz that's where we'll be <img src="/forum/images/smilies/968/wink.png" class="smilie" alt="" />

Partial Post: Please Login or Register to read the full post.

[Cloud9...68]

[quote name='DaveN' timestamp='1344361835' post='130670']

Cloud - Nitrous! <img src="/forum/images/smilies/968/ohmy.png" class="smilie" alt="" /> Best see "Thy Rod no longer Comforts Me" thread cuz that's where we'll be <img src="/forum/images/smilies/968/wink.png" class="smilie" alt="" />

[/quote]

I don't want to come off as some kind of nitrous-sniffing monster truck fan, but I'm not seeing it. I don't understand why adding, say, 50 hp via a low dose of nitrous would put any more strain on an engine than getting the same horsepower increase by adding a small amount of boost via a small turbo or SC. When most people think nitrous, they tend to think of mega-power dragsters downing huge gulps of the stuff, but it seems to me that it might actually be an economical way to get a modest boost in power if used in low doses. I'm only speaking hypothetically, of course, as I don't know if I'd ever do it to my engine, for a variety of reasons.

Partial Post: Please Login or Register to read the full post.

[tamathumper]

If you can keep it to low doses... The dose makes the poison.

Partial Post: Please Login or Register to read the full post.

[flash]

the problem with nitrous is not the power it makes, it's the practicality.



it is only useable in short bursts. it is not easy to control when it comes on. you have to constantly refill the bottle (assuming you can find a spot for it that you can live with)



it makes for great stuff in the movies, but it just isn't a realistic approach to a street car.

Partial Post: Please Login or Register to read the full post.

[Cloud9...68]

Understood. The applications where it makes sense are pretty limited. I was thinking maybe on a race car that is also used on non-competitive track days. In addition to removing the class-mandated ballast, a low-dose nitrous system would be an inexpensive and easily-removable way to get a little more dig out of the corners, to help keep up with some of the six-figure toys that so often grace DE events, I would think. Or maybe on a street car that is only in search of a little extra power on relatively rare occasions.

Partial Post: Please Login or Register to read the full post.

[DaveN]

I was thinking you wanted to No2 the SC and that might turn out very bad......pooooof!

Partial Post: Please Login or Register to read the full post.

[Cloud9...68]

No, no SC here. Probably no nitrous in the future, either. Just thinking hypothetically. It would be fun to see somebody apply low dose nitrous to an appropriately prepared 968, though. I remember reading an article in Roundel years ago where a guy explored the alternatives, and concluded that for his case (an old E30, iirc), nitrous was the most practical and economical way to a modest power boost.

Partial Post: Please Login or Register to read the full post.

[flash]

if they have come up with something that meters the amount of nitrous based on throttle position, then you might have something useable. otherwise, due to the "all or nothing" issue, it's a 1/4 mile thing. we used it a lot on those kinds of cars, but never had a lot of luck with drivability on street cars.

Partial Post: Please Login or Register to read the full post.

[Cloud9...68]

I'm sure the newer ktis allow for that. I've even heard it used by people running big, laggy turbos as a means to just fill in the power gap privided by the lag.

Partial Post: Please Login or Register to read the full post.