dyno session, what a reality check lol

[rbonella]

well, our mustang club had its spring dyno day yesterday. I am disappointed in my numbers. Cars were ran on a Mustang Dyno which i hear is the most accurate real world rwhp/tq chassis dyno, it was a humbling experience to say the least.
357 w/10:1 Venolia pistons
aluminum GT40 heads with 2.02/1.6 valves
FMS B-303 cam with Crane 1.7 RR's
351 Lightning GT40 lower (non-ported) Tubular GT40 upper (non-ported)
75 mm TB
Pro-M 77 mm mass air
AMS 4" power pipe
30lb injectors
Long tubes
2.5" off-road H-pipe
2.5" flows dumped
A9L computer, car was tuned in 1995 using fuel pressure regulator and timing light (old-school)
MSD ignition
Aluminum driveshaft
Tremec 3550 5 speed
RESULTS:
268rwhp @4700 rpm, 333 tq @ 3200 rpm
The motor made 300 ft/lbs @ 2100 rpm and stayed above 310ft/lbs up till 4500, then it dropped off. I was expecting the motor to be a little torquey due to the small heads/intake
But I was praying for 300+hp.
*I was unable to get an air/fuel reading because Iam running turndowns and they hang a bit too low so the air/fuel probe would not fit correctly*
I think I am running a bit rich, and my fuel pressure was @ 44psi throughout the entire run.
Should I have expected these numbers?
In Your Opinion, how much power COULD a tune provide?
How much more power could I have made with properly sized H/C/I?
I registered my car as a 3300 lb car, 1988 GT w/full interior, it was a guess
Sorry for the multiple ?'s
What a reality check!!!!

 

[tannerc91gt]

seems to me that a more aggressive cam and a port job on that intake would make a hell of a difference..dynos can be depressing

 

[$uperstang]

seems to me that a more aggressive cam and a port job on that intake would make a hell of a difference..dynos can be depressing

Agree, also those injectors should be at least 42#s

 

[tannerc91gt]

i think 30s should be sufficient, i didnt see a power adder

 

[bobwb]

seems to me with all your mods it should be putting out at least 350 rwhp? i was thinking about doing about the same mods as you, hoping for at least 350hp, mabye ill think about going to looking at the 2003 cobras again, sure like my 86 gt looks better though.

 

[rbonella]

the injectors are fine,
with 10:1 cr, I've taken myself out of the force induction idea....not worth the money with minimal boost levels
as for nitrous, well I have done a few nitrous cars and I don't think I will be spraying this car in the near future.
This car is for weekend fun, cruisin with the car club, and the occassional 1/8th mile blast.
Any opinions to my ?'s

 

[rbonella]

Bobwb, I was thinking the same thing....at least 325hp? This car has been untouched since 1995, and I know a professional tune would not hurt, but how much could it help. The tuner at the dyno shop quoted me $300-500 for a SCT chipped tune, but would not "guesstimate" on the results due to the fact that we took no air/fuel measirements. Hell, they might be spot on so the gains could be minimal?
Anyone running a 357 with better results? If so, what's the combo?
One member of our club was running a 9.5:1 357 with otb vic jr's, tfs stage 3 cam, super vic efi intake and CLAIMED 385hp, but thats hear-say?
Who friggin knows?!!!

 

[tannerc91gt]

obviously, youd make more power with a tune, but how much is unclear. you really need to get some tailpipes so you can get an A/F reading.
as far as a better matched H/C/I, are those aluminum heads GT40x? the intake and cam are the weak points (b-cam isnt the most aggressive, and the gt40 would do much better with a port) you definitly should be making more power than you are though. you're over 300 crank id say, but theres definitly a potential for more

 

[89stang1]

im surprised your numbers werent a little better but to wake her up id ditch the GT 40 heads and ford cam.......nice set of heads and a custom grind cam even some off the shelf cams by Comp or Anderson would make a big difference especially with a good SCTII tune on the dyno, my stang was dynoed on a mustang dyno too ive seen anywhere from 5 to 15% lower numbers than on a dynojet. Good Luck

 

[rbonella]

I need to trim a little off the turndowns for the probe to fit, not a big deal. I know you're right about the gt40 performing better with a port job, but I feel that a ported upper/lower GT40 is still too small for the motor and I plan on doing a H/C/I as I have posted threads pertaining to that but funds are limited and those parts will have to wait. But 268hp? I was pissed! I might be answering my own question here, but my theory is the intake is running out of flow right when the cam is starting to roll. my parts are not in harmony with each other which is a problem. Dont get me wrong, the car is fun on the street with its flat torque curve (would be a great truck motor haha) but when you want to ring it out, who wants to shift @ 4700? Not me!

 

[89stang1]

ive heard of 50 HP found with a good tune my stang made 30 more HP after Rick tweeked my tune on the dyno

 

[rbonella]

89stang1, the dyno was brutal, a guy with a procharged 4v spun 545rwhp on a dyno jet, yesterday he produced 485rwhp on the mustang dyno...the combo was the same on both dynos. Im not questioning the mustang dyno by any means,

 

[tannerc91gt]

there are definitly much better options for a 351w than the gt40, you may look into an eddie of TFS one

 

[GTA_V6_Mustang]

Seems like some good port work would really help it out. My HCI 302 put down 302RWHP with my old ser-up on a mustang dyno so a larger higher compression engine should do much better.

 

[89stang1]

89stang1, the dyno was brutal, a guy with a procharged 4v spun 545rwhp on a dyno jet, yesterday he produced 485rwhp on the mustang dyno...the combo was the same on both dynos. Im not questioning the mustang dyno by any means,

no doubt but if u dont mind the numbers seems most of the better tuners around use mustang dyno or DynoDynamics

 

[rbonella]

we had a 91 lx with stock block tfs top end kit 302 pull 311 rwhp on the mustang dyno....that's when I freeked out!

 

[rbonella]

89stang1, I hate the numbers haha, but yea...I have always heard the mustang dyno is the most accurate in measuring RWHP/TQ, dynojets are usually more generous.

 

[89stang1]

i got real lucky my combo turned out great my numbers were real good NA on a mustang dyno to the point i havent gone back for my NOS tune yet and its been a year my NOS kit all hooked up minus a tune put on my 4 bank chip. My car has really good power low end tractions been my biggest problem no use spraying and making it a bigger problem also with my smallest shot a 75HP one puts me in not so comfortable numbers with block

 

[90lxcoupe]

Well you are using a cam thats designed for a 302 that is out of date technology wise and an intake that is also way to small for the size of the motor, i'd say the heads are too small too but you should be able to make decent power with those. the fact that it only makes power to 4700 says it all.

Re-think the combo and make use of what you can but get rid of the parts that were designed for 50 less cubic inches with technology thats 20 years old. I dont think that alphabet cams are bad, they are great on a budget, but they have their place

 

[281pony]

we had a 91 lx with stock block tfs top end kit 302 pull 311 rwhp on the mustang dyno....that's when I freeked out!

i pulled similar numbers (300/320) out of my stock bottom ended tfs kit (old casting tfs heads, stage 1 cam, u/l intake.) since i have switched to a new n/a powerpipe and systemax upper. i know it picked up atleast 10 sotp horses

your numbers seem on the low side for sure.