Why am i running a second slower with the charger?!!

S

SiK91LX

New Member
Apr 23, 2003
78
0
0
SF, CA
#1
A month ago i went to the tracks and i ran a 14.1 @ 99with all the bolt ons , headers, pullies, 65 throttle, h pipe, short shifter, a/c delete smog delete, alum driveshaft, cobra clutch....

I took out the pullies and the ac delete and threw in a SN-89 paxton charger, edelbrock performer, 1.7 rockers, 24lb injectors, 77mm MAF, bbk fuel pressure regulator... Ever since i installed my performer intake i've been having idling issues and car would feel slow as hell....

So last night i went to the tracks and i ran a 14.1 @ 100 - Everytime i would change gears my car would feel like its letting air out from somewhere and would sputter then power would come...

Guys looked @ my car and they said to throw in the STOCK INTAKE back on since im RUNNING stock heads and cam.... They said it should throw me back in low 13s easy because the edelbrock is sucking in wayy too much air and stock heads cant handle it...

So what do you guys say? Put the stock intake on and wait till the heads and cam come in?

My goal is to run low 13s with the paxton sn89 - the last owner was running mid 13s with the blower with a stock engine...

Thanks
 
#2
first check to see if there is an intake leak anywhere, grab some propane or carb cleaner and spray it allong the gasket seams and if the idle rises at any time youve got a leak.

many people run the edlebrock manifold on stock motors and have wonderful success so i dont believe that is the pitfall.

a friend of mine with a 1988 gt stock shortblock and heads with the edelbrock manifold, tb,maf, cai, lowering springs,headers, 2cat hpipe, DR's, 100 shot, ran 13.3 in the quarter in palmdale then after som finess and better rear springs, hit 12.6
 
#3
.It feels like the damm edelbrock is acting up even before i installed the charger - i will test it out.. Im gonna throw in the stock intake on and see what difference it makes...
 
#4
It sounds like you have a vacuum leak. If this has happend ever since you changed your intake i wouldnt doubt it. Your mainfold is fine with stock head and cam. Like the previous post above said spray the car down with some carb clean to look for a vac. leak.
 
#6
Do NOT waste your timing putting the stock intake on. Are you running an FMU with those tiny (not enough) 24lb injectors? Is your car tuned in any kind of way? You dont just add boost and expect it to be a rocketship all of a sudden. Please dont listen to the retards who said the performer intake is hurting you.
 
#7
The intake helps you. I bolted the charger onto my stock engine and went 8.71 in the 1/8th compared to 9.15 on motor. Added a 70mm TB, Typhoon intake manifold and 73mm MAF and went 8.12s. Then Swapped to 24lb injectors, changed the FMU disk and got a powerpipe and dropped to 7.80. Went to the 2.95 pulley... 7.42s stock longblock...
 
#8
AXIStang said:
The intake helps you. I bolted the charger onto my stock engine and went 8.71 in the 1/8th compared to 9.15 on motor. Added a 70mm TB, Typhoon intake manifold and 73mm MAF and went 8.12s. Then Swapped to 24lb injectors, changed the FMU disk and got a powerpipe and dropped to 7.80. Went to the 2.95 pulley... 7.42s stock longblock...
Click to expand...
nice :nice:
 
#9
you are fine with the 24# injectors, the sn-89 just doesn't make enough boost to require anything bigger, plus you are still running stock heads and cam. after upgrading the heads and cam, jump up to a 30#er, just to be safe. with injectors, bigger isn't always better. if i can run 24#ers in my car with my setup, you'll be fine. i wouldn't bother putting the stock intake back on either, it's helping if anything. do you have a boost gauge installed? it sounds like you either have a nasty vacuum leak or you're losing boost. you also didn't mention where your fuel pressure is at. if you are running the fmu, lose that and use the regulator and a decent pump to control fuel.
 
#10
Yea i am running a FMU Unit, im also running BBK Fuel Pressure Regulator...

Only VACUUM i think may cause this power loss is the one that goes onto the PCV valve.. I dont have a PCV valve to begin with.. When i bought my Performer the PCV was capped off so i left it sittin there and now the PCV hose from the intake is just sitting there with a breather @ the end of it...... I also have a breather as an oil cap...

Another vacum line that isnt hooked up is the FMU unit line.. The line that goes SOMEWHERE behind the upper intake? If i just take out the FMU then you guys think it will be safe?

---

But listen to this.. I ran the car WITHOUT THE CHARGER BELT and i ran a 14.8 with a 2.1 60ft // I ran a 14.1 with the stock intake before......

---

May i be running too reach or lean? And no, i havent gotten the car tuned... The timing is still STOCK and i have STOCK spark plugs since last August..

SOme told me to bump timing back to 9* and change spark plugs and set the fuel pressure.. Right now it sits @ 45PSI ignition on..

Thanks Guys
 
#12
You can take off the FMU but it is risky. If you blow up your engine, dont come in here blaming us guys. If you have a good ear and know what to listen for, keep running it at that 45psi until you can have it tuned. I dont understand what your are saying about the FMU line, but either bypass it, or hook it up to the FMU. Get some new spark plugs tomorrow and a heat range colder, Autolite 24s. Gap them to .35. Timing is too high, set at 5-7*, not 9*. If you run spout out, it is way safer and torquier, run 21-24*. On the timing start at the lowest number, then increase until power is not picked up or pinging occurs then back off a degree. Also, do you have a bypass valve and is it hooked up and working properly?
 
#13
RydeOn said:
You can take off the FMU but it is risky. If you blow up your engine, dont come in here blaming us guys. If you have a good ear and know what to listen for, keep running it at that 45psi until you can have it tuned. I dont understand what your are saying about the FMU line, but either bypass it, or hook it up to the FMU. Get some new spark plugs tomorrow and a heat range colder, Autolite 24s. Gap them to .35. Timing is too high, set at 5-7*, not 9*. If you run spout out, it is way safer and torquier, run 21-24*. On the timing start at the lowest number, then increase until power is not picked up or pinging occurs then back off a degree. Also, do you have a bypass valve and is it hooked up and working properly?
Click to expand...


No i dont have a bypass valve... I have a feeling the charger is only pushing about 20-30 horses extra so doesnt really need a bypass.. I having the boost guage installed this thursday so see how much it really puts out.. As of now im not gonna drive it till i get everything right..Period...
 
#16
Before you go buying anything, or changing anything you need to have someone look at the car. Sounds like you have some huge vacume leaks. You can't just leave hoses unkooked. They need to be capped, or connected. If you don't know where a hose goes, then you need to find out. I'm sure there are plenty of guys in the ca area that know what they are doing that are willing to help you out. For the minimal amount of boost your running, you don't need a bypass valve either. The sn89 is an old blower, I would guess your only seeing about 5psi.

Make a post looking for guys in you area, maybe one of them can come and look at your ride. Maybe PM groverdill. I'm not sure how close to you he is, but I know he would gladly take a look at it for you.
 
#19
Yes i bought the blower used and no it was in running perfect condition and i even went for a ride inside the car that had the blower installed and it was pulling 5x quicker then mines with less mods...

Only vacuums i can think of iare those 4 small hard tubing vacum lines that are near the passenger side fenderwall.. All 4 of thoe broke last year but my car still ran fine... And the next leak would be the PCV vacuum line - I dont have a PCV valve or the hole behind the lower intake and everytime i capp off the vacuum line the whole car dies :mad: So i left it hanging there with a breather...

And there isnt any more leaks......
 
#20
I bet you that 5 psi you SHOULD be seeing....equates to 20-30 hp right.....So how much Hp do u think you motor is using to spin that old a$$ blower? ..just a thought, its a well know fact that centifrugal superchargers take anywhere from 20-50 fwhp spin the impeller. Whats the point of 5psi? My 02, but also sounds like u have some vacum leaks that need to be addressed.
 
You must log in or register to reply here.

Similar threads

1
Engine 91 mustang 302 Low acceleration car backfires pops and acts like it doesn’t want to take fuel
Replies
16
Views
971
Fox 5.0 Mustang Tech
1991Fox5.0
1
Dontknowchit
Forced Induction Bypass valve backwards?
Replies
3
Views
326
Fox 5.0 Mustang Tech
JD1964
JD1964
2
Running very very rich
Replies
4
Views
317
Fox 5.0 Mustang Tech
Noobz347
Noobz347
S
Fuel ‘88 GT Runs Rich Cold — Fixes Itself When I Unplug Sensors (ECT, MAF, O2, etc.)
Replies
12
Views
756
Fox 5.0 Mustang Tech
Mustang5L5
Mustang5L5
T
First Car, what should I do for power??
Replies
7
Views
221
1996 - 2004 SN95 Mustang -General/Talk-
580HP*428Cj
5
Top Bottom
Back
Forums
Menu