95 Cobra Bolt-on Dyno results.

SVTtripleblack

SVTtripleblack

New Member
Dec 4, 2007
166
0
0
Lancaster, PA
#1
Well lets just say I'm a little disappointed with the #'s I made. It went 241rwhp 281 TQ. (Around 280bhp). I was hoping to have at least 250-255rwhp. My car was running a little lean 14:1. Is this too lean for my car to run safely at WOT? The tuner said it wasn't too bad and running lean on a N/A car isn't as bad as say a turbo setup. Is this true, or B.S? Should I get an adjustable fuel pressure regulator to balance it out? Would putting the stock maf back on help my A/F ratio? Please help guys. Many Cobra guys said these cars were underrated from the factory, but I'm not so sure about that. If my car was underrated from the factory it wasn't by more than 10bhp. I will post the dyno sheet so you can see the A/F ratio. It's in my car and I'm too depressed to get it right now. :mad:
 
#4
I'm with Mike about 14.00 to 1.00 being too lean :nice:

I'd have to say that cost you a bit of power :(

About your Q on the tuner's statement

While there is some truth in the fact that .....
lean is not as bad for NA as for PA

I gotta call :bs: on any kind of attitude that might even hint that lean
to that extent is good or should be accepted when talking about WOT.

Seems like I've seen stock Cobras lay down 230 to 235 rwhp but I can't
be 100% sure about it :scratch:

An aftermarket meter is always a crap shoot if you have no pcm access
to fine tune it.

Some are pretty close and others just are not :shrug:

Yes ... You might could fatten things up with more pressure but I'd not
guarantee the pcm would not try and dial back some of that additional
fuel over time.

Whether or not you should go back to the oem meter ...........

I do feel ... at this time ... I don't see enough air being moved to
render it as being ineffective. It would not be all that far fetched
to suspect that aftermarked meter is causing the lean condition.

With a fuel ratio that high ... I'd think you'd be experiencing the
ping thing in the summer temps :shrug:

I know you are a bit bummed but you now got a baseline :nice:

Don't worry about :nono: Post up the pull :)

Grady
 
#8
SVTtripleblack said:
Well lets just say I'm a little disappointed with the #'s I made. It went 241rwhp 281 TQ. (Around 280bhp). I was hoping to have at least 250-255rwhp. My car was running a little lean 14:1. Is this too lean for my car to run safely at WOT? The tuner said it wasn't too bad and running lean on a N/A car isn't as bad as say a turbo setup. Is this true, or B.S? Should I get an adjustable fuel pressure regulator to balance it out? Would putting the stock maf back on help my A/F ratio? Please help guys. Many Cobra guys said these cars were underrated from the factory, but I'm not so sure about that. If my car was underrated from the factory it wasn't by more than 10bhp. I will post the dyno sheet so you can see the A/F ratio. It's in my car and I'm too depressed to get it right now. :mad:
Click to expand...

Your dyno numbers are a bit low but I also think the lean A/F ratio is costing you HP. An adjustable fuel pressure regulator should fix it and if you aim for a 13.0:1 A/F ratio, you'll need about 8% more fuel to the injectors so that'll mean increasing the fuel pressure (with vacuum detached) from 39psi to 45psi.
The tuner is right about it not being as bad running lean on a N/A engine than on a forced induction engine, but 14.0:1 at WOT is too lean for comfort. It's better to err on the rich side 'cause at least the engine will be at much less risk of pinging.
 
#9
Now I'm seeing some coolant behind my water pump around bottom intake/head area. If this lean issue caused a blown head gasket I'm gonna be pretty peed-off. What do you guys suggest? Should I put the oem meter back on and get a fuel pressure regulator? Or do one or the other? Could this also be from my Diablosport Chip? I know fuel tables were remapped and timing was advanced a little bit, but could this have caused the issue? I'll post up the dyno sheet tonight. I'm at my parents for the weekend and they don't have a scanner here.
 
#10
SVTtripleblack said:
Now I'm seeing some coolant behind my water pump around bottom intake/head area. If this lean issue caused a blown head gasket I'm gonna be pretty peed-off. What do you guys suggest? Should I put the oem meter back on and get a fuel pressure regulator? Or do one or the other? Could this also be from my Diablosport Chip? I know fuel tables were remapped and timing was advanced a little bit, but could this have caused the issue? I'll post up the dyno sheet tonight. I'm at my parents for the weekend and they don't have a scanner here.
Click to expand...

My first thought is ... I'd pull that chip and go back to the oem meter

Then again ...
You don't have a way to compare unless you do another pull :shrug:

I've seen some of the Mustang clubs arrange for a Dyno Day and get a nice
discount at local shops

You know ... 3 pulls for xx bux :)

The chip may be contributing more to the lean condition than that meter ;)

Grady
 
#11
OK guys here is the dyno sheet. Looking at it now, the A/F ratio is only above 14.0 to 1 up to 2,500 rpm. After that it looks like it's where it should be. Grady or anyone else with experience please tell me if this looks ok to you. Do you think I should have it dyno tuned? I don't plan on doing anything else to it for quite a while, if ever. If I do get it tuned, should I use the stock maf or the PMAS? This is bothering me. Is it worth getting tuned? I already have the diablosport chip and I think they charge $100/hr of dyno tuning time. They said they sub-contract a guy to do their Mustang tuning that's experienced with it. He uses Diablosport software. I know it's different for everyone, but how much time does it usually take to tune?
 
#16
Do not get a FPR, thats terrible advice and you don't need it. The only reason to get an FPR in a fuel injected car, IMO, is if you are running very high horse power and the stock unit can't keep up. An FPR will just fight with the algorithm in the PCM and nothing good can come of that. I'd like to see what kind of tables that chip uses for the air / fuel / timing adjustments.

I used to run a JET chip because I didn't know any better. It did get rid of the tip in retard, which was nice, but I don't think it made the car any faster. Get someone to tune it or do it yourself, with the exception of places like Lasota racing, mail order chips won't cut it. I think you're leaving lots of power behind on the tune, you're numbers should be higher then that.

Looking at that dyno graph, it looks like your tune is pulling timing and fuel after the high 4K rpms. Seems like most Cobra's I've seen dyno make it 5500 or so before they start to peter off.

Adam
 
#18
I agree with you. I am going to set up an appointment for a tune tomorrow. Should I take the chip out to make it easier for the tuner, or let it in? (Dumb Question I know). Sorry, but I'm still trying to make this dyno graph bigger. If I make it too big I can't upload it. If I make it too small no one can see it.
 
#19
94CobraPace said:
Remember it depends on the dyno also. Not all dynos are the same, some show higher power to make them look better.
Click to expand...


Yeah you can take the same Cobra to 10 diffrent dyno's and get different numbers every time.

SVTtripleblack said:
I agree with you. I am going to set up an appointment for a tune tomorrow. Should I take the chip out to make it easier for the tuner, or let it in? (Dumb Question I know). Sorry, but I'm still trying to make this dyno graph bigger. If I make it too big I can't upload it. If I make it too small no one can see it.
Click to expand...

If you want send the file to me and I'll up load it through my photbucket.


[email protected]
 
You must log in or register to reply here.

Similar threads

C
Boosted Boss 302 HP/TQ
Replies
0
Views
53
2010 - 2014 Specific Tech
coltoncaskey12
C
J
Help Figuring Motor Choice(Possible future turbo)?
Replies
13
Views
481
1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
Jarhead67
J
from6to8
Progress Thread Progress Thread- From6to8's 1994 Cobra Supercharger install
Replies
420
Views
9K
1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
from6to8
from6to8
D Durden
Place to Avoid: Jamison Auto Group in Gulfport, MS
Replies
45
Views
2K
1965 - 1973 Classic Mustangs -General/Talk-
nickyb
nickyb
A
Vacuum line help
Replies
40
Views
3K
1994 - 1995 Specific Tech
Artyom
A
Top Bottom
Back
Forums
Menu