98 GT dyno numbers

98-GT · 02-02-2007, 11:09 PM

I have a full pi swap, 75mm tb/plenum, underdrive pullies, catted h pipe and flowmaster catback. I ended up with 230 rwhp and 290 rwtq. Im happy with the torque especially since i got all of it by 3500 rpms but am dissapointed by the hp. The car seems to give out at 4500.

spike_africa · 02-03-2007, 08:57 AM

auto or manual? regardless those numbers are low. But it doesnt matter. What matters is what it runs at the drag strip.

If it does feel like its crapping out could be a few things:
1-shitty tune
2- cam timing is off

98-GT · 02-03-2007, 07:35 PM

its manual. the car feels fine driving its just on the dyno graph you can see that its really not making much power after 4500.

White04GT · 02-04-2007, 07:25 AM

Well from what I've heard on the 96-98 GT's if you do a full pi swap you usually see nice gains and better numbers then the 99-04's..numbers seem low specially from the mods you have listed.

98-GT · 02-05-2007, 09:38 PM

do u think i could be running out of fuel at high rpms? I no i dont need bigger injectors but maybe a stronger pump? Im not expecting it to give me much power but it sounds like it might help.

spike_africa · 02-06-2007, 07:04 AM

did you get your a/f ratio logged? if so that would really tell you if fuel is a problem or not.

98-GT · 02-08-2007, 09:22 PM

yea i did get my a/f, and it seems fine i guess fuel isnt a problem.

spike_africa · 02-09-2007, 06:51 AM

If its not that only things i could think of are cam timing is off or shitty tune. Having the cam timing off ca cost you up to 20hp or more if its really bad. i mean there are alot of small things can make it happen.

98-GT · 02-09-2007, 04:48 PM

if the cam timing was off would i notice it while driving, because the car seems to run fine to me but i might just be missing somthing.

r3dn3ck · 02-28-2007, 01:43 PM

no... you wouldn't if they were retarded several degrees but otherwise in sync. I'll betcha your cams aren't timed correctly. You should be making like 20+ more hp minimum.

*03gtmustang* · 02-28-2007, 07:40 PM

Post the graph if you can please.

98-GT · 02-28-2007, 07:44 PM

ok i'll try to post it tomorow night. Also if the timing is off a bit would this damage the car at all?

spike_africa · 03-01-2007, 06:12 AM

Yeah i would still say the cam timing would have to be off for such low numbers.

Wheat · 03-01-2007, 10:02 AM

I'd like to see the graph, too. Stock PI engines typically peak the torque at 4000 RPM and power at 5000 RPM.

98-GT · 03-01-2007, 10:54 AM

i should have the graph up tonight

*03gtmustang* · 03-07-2007, 01:25 PM

Quote:

Originally Posted by 98-GT

ok i'll try to post it tomorow night. Also if the timing is off a bit would this damage the car at all?

Could result in bent valves.

98-GT · 03-10-2007, 09:55 PM

I finnally got to scan my dyno sheets, let me know what you guys think

98-GT · 03-10-2007, 10:02 PM

I cant seem to get the right size of that first one ill try to post it up again later

spike_africa · 03-11-2007, 07:05 AM

Thats one of the worst a/f ratios i have ever seen. It should run right under 13:1 for best n/a power.

r3dn3ck · 03-11-2007, 08:22 AM

big bad lean until 4K rpm. That's a proper maf transfer function away from a much better performance. I'd be surprised if it's not pinging at 3500rpm.

jjtgiants · 03-11-2007, 05:33 PM

Quote:

Originally Posted by spike_africa

Thats one of the worst a/f ratios i have ever seen. It should run right under 13:1 for best n/a power.

I agree....could even run closer to 12:5 and bump up the timing

98-GT · 03-13-2007, 11:15 AM

so is that a/f somthing mechanical or is that in the tuning?

r3dn3ck · 03-13-2007, 12:07 PM

there's exactly 1 way to "properly" tune air fuel ratios. That's the MAF transfer function. You tinker with that with a custom tune.

*03gtmustang* · 03-13-2007, 08:31 PM

http://forums.modulardepot.com/uploa...487d4a5cf6.jpg

Thats what your a/f should look like. Yours is terrible and thats why you're down on power. Find a new tuner.

r3dn3ck · 03-14-2007, 09:48 AM

much better. Nice and smooth.

02-02-2007, 11:09 PM	#1 (permalink)
98-GT Member Join Date: Jan 2006 Location: New Jersey Posts: 56	98 GT dyno numbers I have a full pi swap, 75mm tb/plenum, underdrive pullies, catted h pipe and flowmaster catback. I ended up with 230 rwhp and 290 rwtq. Im happy with the torque especially since i got all of it by 3500 rpms but am dissapointed by the hp. The car seems to give out at 4500.

02-03-2007, 08:57 AM	#2 (permalink)
spike_africa Administrator Join Date: Sep 2004 Location: Orlando,Florida Posts: 6,657	auto or manual? regardless those numbers are low. But it doesnt matter. What matters is what it runs at the drag strip. If it does feel like its crapping out could be a few things: 1-shitty tune 2- cam timing is off __________________ Dustin 2002 GT Mustang 5-Speed Drag Radials,Sprayed,Powershifted WOOO HOOOO!

02-04-2007, 07:25 AM	#4 (permalink)
White04GT Procharged Join Date: Sep 2005 Location: Kingwood, Tx. Posts: 901	Well from what I've heard on the 96-98 GT's if you do a full pi swap you usually see nice gains and better numbers then the 99-04's..numbers seem low specially from the mods you have listed. __________________ 2004 White GT just another Procharged GT. 370rwhp/396rwtq 8#'s. Gator boots, with the pimped out gucci suit.

02-06-2007, 07:04 AM	#6 (permalink)
spike_africa Administrator Join Date: Sep 2004 Location: Orlando,Florida Posts: 6,657	did you get your a/f ratio logged? if so that would really tell you if fuel is a problem or not. __________________ Dustin 2002 GT Mustang 5-Speed Drag Radials,Sprayed,Powershifted WOOO HOOOO!

02-09-2007, 06:51 AM	#8 (permalink)
spike_africa Administrator Join Date: Sep 2004 Location: Orlando,Florida Posts: 6,657	If its not that only things i could think of are cam timing is off or shitty tune. Having the cam timing off ca cost you up to 20hp or more if its really bad. i mean there are alot of small things can make it happen. __________________ Dustin 2002 GT Mustang 5-Speed Drag Radials,Sprayed,Powershifted WOOO HOOOO!

02-03-2007, 07:35 PM	#3 (permalink)
98-GT Member Join Date: Jan 2006 Location: New Jersey Posts: 56	its manual. the car feels fine driving its just on the dyno graph you can see that its really not making much power after 4500.

02-05-2007, 09:38 PM	#5 (permalink)
98-GT Member Join Date: Jan 2006 Location: New Jersey Posts: 56	do u think i could be running out of fuel at high rpms? I no i dont need bigger injectors but maybe a stronger pump? Im not expecting it to give me much power but it sounds like it might help.

02-08-2007, 09:22 PM	#7 (permalink)
98-GT Member Join Date: Jan 2006 Location: New Jersey Posts: 56	yea i did get my a/f, and it seems fine i guess fuel isnt a problem.

02-09-2007, 04:48 PM	#9 (permalink)
98-GT Member Join Date: Jan 2006 Location: New Jersey Posts: 56	if the cam timing was off would i notice it while driving, because the car seems to run fine to me but i might just be missing somthing.

02-28-2007, 01:43 PM	#10 (permalink)
r3dn3ck Wowbagger hates me too! Join Date: Nov 2005 Location: Magrathea/California Posts: 6,513	no... you wouldn't if they were retarded several degrees but otherwise in sync. I'll betcha your cams aren't timed correctly. You should be making like 20+ more hp minimum.

02-28-2007, 07:40 PM	#11 (permalink)
03gtmustang Super Moderator Join Date: Jan 2005 Location: Northern Va Posts: 3,098	Post the graph if you can please. __________________ D&D Auto Detailing -Dan

02-28-2007, 07:44 PM	#12 (permalink)
98-GT Member Join Date: Jan 2006 Location: New Jersey Posts: 56	ok i'll try to post it tomorow night. Also if the timing is off a bit would this damage the car at all?

03-01-2007, 06:12 AM	#13 (permalink)
spike_africa Administrator Join Date: Sep 2004 Location: Orlando,Florida Posts: 6,657	Yeah i would still say the cam timing would have to be off for such low numbers. __________________ Dustin 2002 GT Mustang 5-Speed Drag Radials,Sprayed,Powershifted WOOO HOOOO!

03-01-2007, 10:02 AM	#14 (permalink)
Wheat Member Join Date: Feb 2007 Location: Northern Virginia Posts: 49	I'd like to see the graph, too. Stock PI engines typically peak the torque at 4000 RPM and power at 5000 RPM.

03-01-2007, 10:54 AM	#15 (permalink)
98-GT Member Join Date: Jan 2006 Location: New Jersey Posts: 56	i should have the graph up tonight

03-10-2007, 10:02 PM	#18 (permalink)
98-GT Member Join Date: Jan 2006 Location: New Jersey Posts: 56	I cant seem to get the right size of that first one ill try to post it up again later

03-11-2007, 07:05 AM	#19 (permalink)
spike_africa Administrator Join Date: Sep 2004 Location: Orlando,Florida Posts: 6,657	Thats one of the worst a/f ratios i have ever seen. It should run right under 13:1 for best n/a power. __________________ Dustin 2002 GT Mustang 5-Speed Drag Radials,Sprayed,Powershifted WOOO HOOOO!

03-11-2007, 08:22 AM	#20 (permalink)
r3dn3ck Wowbagger hates me too! Join Date: Nov 2005 Location: Magrathea/California Posts: 6,513	big bad lean until 4K rpm. That's a proper maf transfer function away from a much better performance. I'd be surprised if it's not pinging at 3500rpm.

03-13-2007, 11:15 AM	#22 (permalink)
98-GT Member Join Date: Jan 2006 Location: New Jersey Posts: 56	so is that a/f somthing mechanical or is that in the tuning?

03-13-2007, 12:07 PM	#23 (permalink)
r3dn3ck Wowbagger hates me too! Join Date: Nov 2005 Location: Magrathea/California Posts: 6,513	there's exactly 1 way to "properly" tune air fuel ratios. That's the MAF transfer function. You tinker with that with a custom tune.

03-13-2007, 08:31 PM	#24 (permalink)
03gtmustang Super Moderator Join Date: Jan 2005 Location: Northern Va Posts: 3,098	http://forums.modulardepot.com/uploa...487d4a5cf6.jpg Thats what your a/f should look like. Yours is terrible and thats why you're down on power. Find a new tuner. __________________ D&D Auto Detailing -Dan

03-14-2007, 09:48 AM	#25 (permalink)
r3dn3ck Wowbagger hates me too! Join Date: Nov 2005 Location: Magrathea/California Posts: 6,513	much better. Nice and smooth.