PDA

View Full Version : Yet another new time



fturner
08-08-2009, 07:28 AM
Went to the track last night and managed to get 3 runs in, before I was told thats it until I get a helmet :D, which actually made me laugh.

Best run
RT: .244
60': 2.106
330: 5.885
1/8: 8.952
MPH: 80.81
1000: 11.587
1/4: 13.810
MPH: 101.62

The other 2 runs where 13.980@101.13 and 13.861@101.20.

Since the last time, I've gone to 15% OD on the blower, which from what I'm seeing is hurting my car. At 10% OD I was getting the same times but trapping faster at 102.5mph. My ACT's ended up being about 15 to 20 degrees higher at the top end, which means more timing is getting pulled.

At 10% OD I was seeing about 13.2 pounds of boost at peak, with evidence that there was belt slip, and it was mentioned to me that my 5% JS pulley may have become polished with the belt slip I had last year.

At 15% OD I was seeing about 15.1 pounds of boost at peak, and no evidence of belt slip.

I think that 15% may be too much for the stock inlet and/or blower at the track, but its alot of fun on the street :). I'll probably drop back to 10% next time at the track.

I've also took the plunge and turned off my knock sensor and I'm running the car with 26 degrees of timing with 94 octane fuel. All is good so far :).

Unfortunately, on my last run I heard a clunk from the rear of the car about half way up the track that I need to check out. The car is running fine and doesn't feel any different, so I'm hoping its nothing.

Thats it until next time....

Fraser

Edit: I also did one run with spinning up the tires before staging and not a wit of difference.

m.lee
08-08-2009, 08:29 AM
That's a pretty decent time for a SC in the 1/4 mile,can you tell me the base HP and torque rating on a 1994 SC.I've had mine for years but never got into any high performance thoughts with it.It has always seemed to be a pretty fast car for out of the factory though.The main reason I bought it because I just love the body style and having a blower is cool,i like the blower whine when the radio is off.

XR7 Dave
08-08-2009, 11:40 AM
A 15-20 deg increase in temps typically would result in a 2-3% drop in power which, in this case probably equates to about 10rwhp. However, an increase in MAF voltage of 4.3/4.0 indicates an increase in airflow of 7% which should net an increase in power of 4-5%. Clearly this did not happen, the reason why is a very good question.

I have encountered a similar situation with another car that is very similar to Fraser's, the biggest difference being that Fraser is using a ported 94 blower and stock ported plenum whereas I am using an MPIII and matching plenum. It would seem that the plenum is not the limiting factor here.

Both of these cars are using a double IC, which I fear may be the biggest problem. I have run a double IC in the past with success and in fact switching to a MPFMIC did not increase power in at least one case, however, as with any "personal experience" result, caution must be exercised in making judgments due to the lack of scientific evidence.

I think Fraser's experiment has shown valuable evidence about what happens with our motors and why our quests for HP are sometimes thwarted and the results seem to defy explanation.

fturner
08-08-2009, 03:52 PM
For anyone interested and has logworks installed (recommend v2 as v3 has some bugs), here's the log of my 13.810 run last night.

Also, I've taken a closer look at boost levels and I think I am getting belt slip since boost is coming up at each gear change but dropping off again during that gear for other reasons. I also peaked at 15.7 pounds just after the 2-3 shift, and then it slowly tapered off.

Fraser

91bird
08-09-2009, 04:49 PM
Good time Fraser,
Did anyone else make it?
I was not able to.

Drew

fturner
08-09-2009, 05:17 PM
Steve showed up... he was having some tire spin issues but he said the tire pressure was too high.

Fraser

bigpoppa822
08-10-2009, 04:15 PM
Frit, are you running the MP springs? I installed them in my car last year and they made a big difference. Belt slip still isn't eliminated and I go through blower belts a lot faster than a stock SC, but there is no longer 1/2" of powdered rubber on my blower snout.

fastsc92
08-10-2009, 04:47 PM
Nice job Fraser,

Looks like your ACT temps are on the edge of getting timing pulled(unless you changed the settings). Looks like you're experiencing slight belt slip in the high RPM ranges. Otherwise, it looks like a solid clean pass. Some suspension and a better launch could net you a low 13 sec pass. Keep it up!

fturner
08-10-2009, 05:23 PM
Thanks guys... I'm running the mp springs now, but I am experiencing major belt slip and it requires being in 3rd gear and slow rpm build to let the blower come up.

The tensioners are about an 1/8" away from the stops, so I need to reclock them so the belts don't get unloaded.

There's more in the car yet even with just 10% OD which is what I'm going back to. The ACT's where already pulling timing as I'm using the stock settings.

Fraser

fastsc92
08-10-2009, 05:35 PM
Yea, I was looking at the act temps and commanded spark. Looks likes its only a degree or so, but the knock sensor looks un-triggered as you mentioned, which is a good sign.

Jamez
08-13-2009, 02:01 PM
Do you have a mod list somewhere or can you post it?

fturner
08-13-2009, 08:54 PM
Everything is listed in my Member Page which the link is below my user name at the top of each post. This link
http://www.sccoa.com/forums/showthread.php?t=108205 shows what it looks like under the hood now.

Fraser

ps ignore the pics.. that was the car when I got it... it doesn't look like that now.