Stevil

Ok, went to the dyno today. Outside temp~90f. Run temps were ~55cel(they had a small fan which did no good). Boost was .98 at highest and .85 at lowest. Did 5 runs total with the last one the best(my image has the last 3 runs on it, sorry not in color, I could not get it small enough). Also, could not get RPM readings so no torque values, just HP and A/F.

well, from what I have read on here and with my mods(in sig below), I thought I would easily attain ~330hp. But my best run was 273.9 to the wheels. Maybe we need more proof from the posters on this forum. Some one(claims) they got 383hp with stock twins, thats 110hpmore from everything I have plus a streetport and I guess a midpipe and 2 more boost(I was at 15) on the inefficient stock twins, hmmm. I am not going to be a believer until I see the proof. I see why lots of people need to see, lots of boasters here w/ no backup.

Ok, but maybe I have a problem. My twins have 80k on them, but no oil leaks. My motor has 20k(standard rebuild). Maybe my high flo cat is blocked. They are suppose to last, but, I thought my car was louder and more powerful when I first put it on, but I could just be imagining it. My car is not loud w/ dp, high flo and n1 duals, no silencers, not loud at all. Could the temps be a big difference. I was seeing 42 cel after the drive home w/ little boost. Still seems high.

The difference in the runs was due to tuning w/ the datalogit by Chuck(rotary extreme), he was a great guy to help out.
I thought my setup was running rich. I got my PFC from SR motorsports tuned with all the mods. Maybe his tuneing is not rich at all, mine was not, I think 11.6 the first run in third gear at .83 boost.

Oh ya, I had my alcohol injection running the whole time(comes on at 10psi). Would this have any effect on the A/F readings?

Any comments, suggestions, rips, anything, welcomed(encouraged)

Steve

Stevil

Ok, damn dyno di not upload. So here it is.

Steve

RETed

The dyno run looks like it was heading for 300 before all that top-end break-up.&nbsp Either you're running way too much fuel or you've got nasty ignition break-up - you're supposed to running in the 12.x:1 ratio range, but the AFR's dump like the stock market at the top end.


-Ted

87GTR

iTrader: (61)

wow those a/f drop like rock

Anthony Rodrigues

You have got way to much alcohol running in that thing! Start by leaving the fuel and slowly turning the alcohol down. You should find that it will need only very little alcohol at that boost, it should actually loose power. If you are just opening up a dump of alcohol, dont bother you will loose more than it is worth unless you intend to run higher boost.
Regards-Anthony

Stevil

So, is the Alcohol causing my A/F readings to be off?

What would cause, if i had it, ignition break up? I just replaced the plugs before the run. I have the HKS ignition amp.

Basically, after about 80mph on my dyno, my A/F is heading south and it should not be? At about 95 I seem to hit max hp at about A/F 11-x1, at that point should my HP keep climbing(w/ proper A/F, up in the 11,s)?

Thanks,
keep the comments coming.

Stevil

Could my HF Cat be clogged? I have been reading even these can go bad. Any more ideas and solutions?

I listened to a FD that had DP, HF and apexi n1 duals w/ silencers. That car sounded just a tad(a small tad) bit quieter than mine(I do not have silencers and dont want them). I hear these stories about N1 duals and how loud they are on cars(w/ cats). Mine is not bad at all(maybe thats bad).Whats the best way to tell if cat is clogged?

Steve

LUV94RX7

iTrader: (3)

I had a dp, stock cat and straight pipe from the main cat and it was not that loud. I was really surprised.

Ken

Wade

iTrader: (1)

Stevil,

1) where was the wideband probe located in the exhaust? If after a cat, the readings can't be trusted. The readings are likely leaner than actual. This means the 11.6 you saw might have been a 10.6. Then you added more fuel!

ASSUMING the wideband reading is before any cats:

2) you need to add fuel below 4500 RPM to get that a:f down to 13 or perhaps 12. This won't do anything for max power but it will keep your car from knocking when loaded at low RPM.

3) I can't tell which run is which, but your a:f is really taking a nosedive at around 6000 RPM, you need to shoot for 11 or even 11.5. Maxxing out the wideband at 10:1 is definitely not good for power. Your power is very rough up there too, which means you are probably getting rich misfire.

Wade

zyounker

NO!!! Wade, you have it backwards!


if you run 13:1 A/F you will most likely kill your motor! Do not do it.


-Zach

AnthonyNYC

iTrader: (3)

Hey Steve,

Sorry about those numbers, I kinda sense your frustration in the writing. I made 386HP on the stock twins and run consistent low 11s. (best was 11.1@122MPH) but I will tell you that MANY FD owners are pushing easily over 350HP@15psi when tuned right. Josh Stanley runs mid 11's, John Duarte on stock intercooler, stock injectors etc runs consistent low low 12's.
Just look closer at your setup. If you think its the HF Cat then take it off. 4 bolts and it comes off, dyno the car without it.
You didnt list your mods.

Anthony

Stevil

Wade,
Ya, wideband was after cats. Actually, fuel was never added. A bit was taken away every run. We were trying to get the end of the A/F to level out more. Just did not want to overdo it.
In regards to which run is which, The top hp line is the middle A/F line. The bottom Hp line is the bottom A/F line. The last run was the top HP line.
My knock readings were all pretty low in all runs.
So add fuel lower Rpms, and subtract at higher RPMS?


Anthony,
Exactly my point. It seems many are running about 350 and with what I have(I will post sig). So my measly 273 is weak .
Anybody have PFC maps w/ similar mods as mine that has dyno'ed in the low to mid 300's? That would be best way to compare.

Again thanks.

Stevil

Oh, another question that just popped to mind as I was driving the tank around;

On the dyno using datalogit, I set my boost to .98. On my runs my boost would build to .98 and just hit it once for a fraction of a second(whatever the datalogit reads in). So it would go .84 .85 .86.... .98 .94 .92 .88 etc. Not sure what RPM it hit .98, but shouldnt the boost stay at .98(if thats the setting, it did this on lower settings too) and not drop after hitting my set boost? Is this a duty cycle adjustment that is needed?

Thanks,
Steve

Wade

iTrader: (1)

Stevil,

If the wideband is after the cats then you are tuning in the dark. Most likely the real a:f is richer than indicated, by how much you can't be sure. Remove your cats or put the wideband sensor before the cats next time. This is absolutely necessary!

Okay, so you were reducing fuel. Assuming your a:f *trend* is correct (but the actual numbers are probably different!) then yes, it looks like you need to add quite a bit of fuel at lower RPMS and reduce fuel a LOT at higher rpms. It looks like most of your fuel reductions had an affect on lower RPMS, this is not where you want it!

Your power leveling off is clearly correllated with your a:f taking a rich nosedive. Get it leveled to mid or low 11's from about 4000 RPM + and your max power will go up drastically.

Zach,

You must be confused. I said to reduce his a:f to 12-13 (his dyno indicated the a:f going from 16 to about 13, far leaner!)

Wade

zyounker

Sorry, i just re-read it and you are correct.. I though you where telling him to lean it out to ~13:1 through the whole run..

-Zach

The_HITman

I would not take it any leaner than 12.0:1 if you want it to last, with 11.7:1 much safer and the power loss is very small over running leaner.
It does look like ignition breakup but it could be partly related to the over rich mixtures. What are you running for spark plugs ?
I too would bring back the alcohol amounts, and even turn it off until the engine is tuned better, then go back to using it. It is best to fix one problem at a time.

Stevil

I am running NGK 9's and 7's. I just installed them the day before the run. What would cause the ignition breakup? Faulty connection, bad wires(they are Magnacor 10's and have only 5k miles on them, if that).

Wade

iTrader: (1)

Stevil,

Both Hitman and I mentioned that your breakup could be caused by misfire from being too rich. Correct your a:f first and you will probably not have the breakup.

Wade