quote Originally posted by TiredGXP: Darth, This is a much more reasonable result, very close to expectation. I took a look through the log file. Looks like this engine is flowing about 10-12% more than stock in the upper RPM range (based on dynamic cylinder air numbers), which definitely helped retain torque and power above 5,600RPM. The porting job definitely paid off. If you're up for a bit of unsolicited comments on the log, here goes: A little bit of KR is showing up, so it might not hurt to back the WOT timing off a degree or so. Commanded AFR in PE seems a bit lean @ 13.5, it wouldn't hurt to richen it up to 12.8 ~ 13 (although the WB shows ~13, if it was in the tailpipe after the cat the reading could be out a few tenths). Cheers

I plugged a wideband O2 sensor in before the cats and went for a drive before doing these dyno pulls and the commanded AFR in PE is showing about 0.5-0.7 more than actual (command = 13.5, actual = 13.0). I have the raw numbers from the dyno runs today for the tailpipe AFR sniffer and it was showing 12.35:1 AFR by 6000rpm, which of course are after-cat readings. Keep in mind too the humidity in the dyno cell was about 20% today and the temps were pretty cool; basically ideal. This summer, higher humidity and temps are probably going to result in this engine running richer than it is now with the current ECM settings for PE. So I hesitate to change them. One thing I might do is go in and turn up the PE fuel a little but under 4500 just to even out the AFR curve.

quote Originally posted by Darth Fiero: I plugged a wideband O2 sensor in before the cats and went for a drive before doing these dyno pulls and the commanded AFR in PE is showing about 0.5-0.7 more than actual (command = 13.5, actual = 13.0). I have the raw numbers from the dyno runs today for the tailpipe AFR sniffer and it was showing 12.35:1 AFR by 6000rpm, which of course are after-cat readings. Keep in mind too the humidity in the dyno cell was about 20% today and the temps were pretty cool; basically ideal. This summer, higher humidity and temps are probably going to result in this engine running richer than it is now with the current ECM settings for PE. So I hesitate to change them. One thing I might do is go in and turn up the PE fuel a little but under 4500 just to even out the AFR curve.

Well, if the WB is reading 13 before the cat, then yeah, no need to change PE settings if you're not messing with the MAF and VE tables.

I have my PE equalization ratio set to one value across the board, and just lowered the RPM PE delay to 2500. Since the torque converter is going to let the engine flash past that threshhold, PE comes on instantly whenever the TPS is over 80%. This seems to work for me, PE isn't entered in normal, sedate driving, but is available whenever you just have to pass that other car

Cheers

Nice dude. That's a kick ass drivetrain - modern fuel injection, DoD, it comes with the right bellhousing and a FWD transmission that's actually meant for heavier cars with the same engine. Should be a pretty quick ride.

quote Originally posted by TiredGXP: and just lowered the RPM PE delay to 2500.

I did this same thing. Can't believe the stock value was 5000rpm. But I guess they were just trying to save fuel everywhere they could.

Congrats Blkcofy and Darth! Looks like you got yourself a fun ride there. And now you have a good base-line to compare any future mods to. And you will still get some good gas mileage.... if you can keep you foot out of it.

quote Originally posted by darkhorizon: My 12.8 second car makes high 250's on my friends mustang dyno, and I have a ton of powerband advantages over the LS4.

How about posting up your dyno chart. Maybe some other 3.8SC people will join the thread and discuss your results. I have to admit that I never paid much attention to the 3.8SC's since both of my 3.8's are normally aspirated.

Cheers

The dyno I used didnt really have any provisions to print a dyno graph, and i didnt bring my thumb drive... so I didnt save it, and I really didnt care I was just screwing around on it anyway. I will post one up later when I go again this year.

There are a few threads around that show 250ish out of 3800's, and my car is just as fast (like perfectly identical at the track) as akursed with 257whp on a mustang dyno..

quote Originally posted by TiredGXP: How about posting up your dyno chart. Maybe some other 3.8SC people will join the thread and discuss your results. I have to admit that I never paid much attention to the 3.8SC's since both of my 3.8's are normally aspirated. Cheers

Already did that on page 2 but not many people seem to be discussing 372 rwhp from a 3800SC.

"new computer management is the next step"

Are you like tuning with an AFC or what? Its been proven time and time again that gm pcms will go well far enough to put down 700whp.

quote Originally posted by PURPLE REIGN: Already did that on page 2 but not many people seem to be discussing 372 rwhp from a 3800SC.

You know, I completely missed the link to the vid in your original post. 372 whp is impressive. Do you have a build thread on this? How did you solve your transmission problems?

I still want to see the "ton of powerband advantages over the LS4" that darkhorizon, on several occasions, has told us his engine produces. There's no doubt that the 3800SC can produce impressive power and torque numbers; I figured that an amateur dyno operator (whose friend owns a dyno) ought to have the odd dyno chart kicking around to show us how well his engine works.

:cheers:

Here is a direct comparison of dyno graphs from Blkcofy's and my car's dyno pulls. Now these weren't done at the same time or same place, but if you look at the graphs, the hp is graphed the same and the torque is a little different, but this still shows a comparable horsepower curve. I really don't see a great difference. I'd say that the LS4 actually has a better curve than mine. It breathes well all the way over 6k where mine has more of a drop. All I know is that I was producing a hell of alot more torque, but I would get pulled at the top end......for now

Here's my graph:


Here's Blkcofy's graph:



No matter what dyno was used, I think the curves would pretty much be the same, so hopefully this can put an end to this argument.
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'88 GT- 257rwhp 319rwft/lbs 12.95@106.1mph

[This message has been edited by AkursedX (edited 03-29-2008).]

quote Originally posted by darkhorizon: "new computer management is the next step" Are you like tuning with an AFC or what? Its been proven time and time again that gm pcms will go well far enough to put down 700whp.

This I know. The debate between the Dyno Tuner, a partner who build DSM's and " Brian" @ Intense are all trying to solve it. "Brian" has already comfirmed the stock PCM is good to 1000hp if you know how to trick rework it. No AFC right now.

quote Originally posted by TiredGXP: You know, I completely missed the link to the vid in your original post. 372 whp is impressive. Do you have a build thread on this? How did you solve your transmission problems? I still want to see the "ton of powerband advantages over the LS4" that darkhorizon, on several occasions, has told us his engine produces. There's no doubt that the 3800SC can produce impressive power and torque numbers; I figured that an amateur dyno operator (whose friend owns a dyno) ought to have the odd dyno chart kicking around to show us how well his engine works. :cheers:

This was posted in the 3800SC 1/4 mile time thread, but was unable to link it. Were looking to hit the 440 rwhp mark.

Diamond Forged Racing pistons
Speed Pro Moly Rings
Series III rods
Balance shaft eliminated
PRJ double roller timing set
Custom grind cam ( cant remember spec's ) still installing it
Comp Cams custom 7016 pushrods
Meziere electric water pump
ARP Studded block
4 layer Cometic gaskets
Ported & polished heads
SI Stainless Oversized Valves & pocket porting
High Performance LS-1 springs
Yella Terra Aluminum Roller tip rockers
Titanium retainers
Ported & matched intake
Internals cryogenically treated, balanced & blueprinted
ZZP full size water to air intercooler
Custom 1.75 equal length headers, coated
60lb Motronic Injectors
PRJ Custom Fuel Rail & adjustable regulator
Autolite 103's
Taylor wires
MP 112 Blower w/ 3.0 pulley @ 19lbs boost
LS-1 Throttle body
4" CAI
3" madrel bent exhaust, Flowmaster muffler
LM-1 Wide Band O2 kit
MSD Boost-a-Pump
G.N. Fuel pump
SLP Mass Air Sensor
100 shot wet Nitrous kit ( not used yet )
Custom PCM by Loyde ( and still tuning )
Accusump ( dry-sump back-up )
and those freakin motor mounts by Purple Reign

I know I'm missing something

Transmission -
" Red Line " built
ZZP 300m Input Shaft
ZZP 2750 Stall Torque Converter
Internals cryogenically treated including input shaft & 4th clutch hub
Quaife Torque Biasing Diff.
Thrasher Shift Kit

[This message has been edited by PURPLE REIGN (edited 03-29-2008).]

The dyno is a nice tool for getting a base line and tuning but thats about it. I went to the dyno with a group of SHO guys a while back just to see what my car out down and it was cheap. The highest of my runs where 267 HP with slightly higher torque numbers and that was the best of 3 runs. I thought the numbers where low but I still posted them and didnt worry with what others said. I was going to take the car back to another shop and do some more pulls but never got around to it before I went to the track. The best I have put down at the track was 12.0@111 so this tells me my car is putting down more that what the dyno said. I would still llike to take it back to the dyno for a tune but not forsure when that will happen.