Ford Mustang Forums banner

1 - 12 of 12 Posts

·
Registered
Joined
·
472 Posts
Discussion Starter #1
Spent most of the day getting this swap done. It wasn't really difficult, but not being throught it before set me up for several mistakes along the way. My only issues to solve for tomorrow are that my stock hood will not close, and that the 'elbow' i have doesn't join the Powerpipe to the JT inlet. It's too small on the end that used to go to the S-trim. Can't wait to see how it feels on the street!! I won't make it to the track until the 55#s are in and it's tuned. That could take a little while. Need more $$. I'll have to keep my eye on the boost gauge until then!

Dave
 

·
Registered
Joined
·
771 Posts
awesome, congrats man. :D I cant wait to hear what you think of it, this will be my next upgrade. :D

Question for ya though, why was your car only making 13psi with the 2.80 pulley? Do you loose that much boost through the SHM intercooler? :) Just wondering.
 

·
Registered
Joined
·
472 Posts
Discussion Starter #3
You know, i don't really know the answer to that. I previously had a 2.62" pulley from SHM and was seeing 16-17psi but i was shredding too many belts. The 2.80 RR pulley was Cobra killer's idea and it stopped the belt wear immediately. But the gauge read 3 psi less on the larger diameter. The Intercooler is supposed to be a low resistance one. I've heard you lose about 2 psi. I've heard alot of people seeing higher boost levels with much larger pulleys than mine. I can't figure it out. Unless, my heads, intake, and cam specs flowed better with less resistance and thus less boost. I wish i knew.

dave
 

·
Registered
Joined
·
1,558 Posts
What size pulley you running?
 

·
Registered
Joined
·
1,558 Posts
IMO I wouldn't run the car hard once you swap blowers until you get that retune Rammer. The JT blows out A LOT more air then an S-Trim. You will probably be running pretty lean once you swap it out.
 

·
Registered
Joined
·
472 Posts
Discussion Starter #7
rancid, so you think that even if i lay off before 10psi, i could be risking a lean condition? I thought that with my FMU still on, my fuel pressure should rise according to boost levels in the intake. If the JT flows more air throughout, i should be reaching 10psi much earlier in the rpm band, and need to shut down at say 4500rpm rather than 5500 so i don't max out my 42#s. Am i missing part of the equation here? I definitely don't want to f*&*^k things up. I won't be able to get my tune until mid August.

dave
 

·
Registered
Joined
·
751 Posts
Dave,

Altough the JT does pump a lot more air, you still should be fine for driving (NOT racing). Your FMU and mass air will adjust accordingly (to a point) for the bigger blower. Yes it should give you more power throughout the midrange, and build 10 psi faster than the S trim did, but if you keep it under 5000 rpm, you should have more than enough fuel to keep things safe. I drove your car for a weekend, so I know the tune is safe enough to do this. My .02 of course. Have I ever steered you wrong before rammer........ummmmm, don't answer that!

Scotty
VT
 

·
Registered
Joined
·
1,558 Posts
What was your A/F looking like before the swap? If it was tuned for safety purposes before you shouldn't have a problem then I wouldn't think. You may want to PM David Posea on these boards he does tuning and can give you a definite answer.
 

·
Registered
Joined
·
472 Posts
Discussion Starter #10
I just e-mailed Scott a copy of my A/F graph. Scott, feel free to post it here if you can, since i don't know how.

dave
 

·
Registered
Joined
·
771 Posts
rammer said:
You know, i don't really know the answer to that. I previously had a 2.62" pulley from SHM and was seeing 16-17psi but i was shredding too many belts. The 2.80 RR pulley was Cobra killer's idea and it stopped the belt wear immediately. But the gauge read 3 psi less on the larger diameter. The Intercooler is supposed to be a low resistance one. I've heard you lose about 2 psi. I've heard alot of people seeing higher boost levels with much larger pulleys than mine. I can't figure it out. Unless, my heads, intake, and cam specs flowed better with less resistance and thus less boost. I wish i knew.

dave
Hmmm......very weird. :) I am putting the 2.80 RR pulley on next week (if it arrives). Right now the belt slips on the low end but i see 15-16psi at 6200 with the 2.87 Vortech pulley and a paxton intercooler.
 
1 - 12 of 12 Posts
Top