detonation

[victor]

my car is mostly stock and im having a detonation problem. i got my novi 1000 and installed it about a month ago. if i run my timing at 10* thats when i get detonation, but if i back it off to about 7* its ok, but im not getting full power with the timing that low. I have stock injectors stock fuel pump, and fuel presure is at 34 pounds. will off road H pipe make the car run lean with my combination. and also were would be the best place i could get a bypass valve for the best price. anything info would help guys thanks. also do i need a boost retard with ony 5 pounds of boost.

[frank woodall]

no a h pipe will not effect air/fuel ratio on a near stock combo. However YES you most certainly , absolutely DO need a boost retard of some type. then you can advance your timing to 10 - 12 where it should be at. I use a Vortech boost retard. you can use a MSD6al btm or a paxton retard box or a vortech retard box. By the way i live in Bradenton,Fla and a good friend has a Vortech boost retard for sale for $50.oo Its the cockpit adj. unit. get a by-pass valve (charge air) for a 2000 Saab A4 Turbo its about $35.00

[victor]

thanks frank

[victor]

thanks frank

[root]

Are you using the FMU?

Ian

[victor]

yes im using the fmu

[Chuck]

first of all raise your fuel pressure to 40 psi that may help.

It is supposed to be 40 psi with the vacuum line to the regulater disconnected, is that how you check it?

a BTM can be of great help I would suggest going and getting the MSD 6BTM is has solved alot of probs for me like spark blowout and detonation.

I just installed it yesterday and I am very pleased with it.

[Doug]

Originally posted by frank woodall
no a h pipe will not effect air/fuel ratio on a near stock combo.

Actually an Off road H-pipe will affect your air fuel ratio. If you free up the exhaust, you will in turn lean out your motor because it becomes more efficient. You will need to add more fuel after you do this. As far as your detonation is concerned, add more fuel. Get a BTM and then you can play with your timing. Always tune your motor a little on the safe side so you don't have to change the headgaskets or worse burn a piston.
Doug

[468LC]

When is the pinging happening? Is it at WOT or part throttle but goes away with WOT.

How many miles on the motor.

[victor]

the car has 140 thousand and it only pings under wide open throttle. thanks

[Chuck]

I would suggest at least backing the timing off until you get a btm.

You could also use colder spark plugs that can help keep the combustion chambers cooler.

Try an autolite 24 or colder yet 23

[frank woodall]

to be technical , yes an H-pipe will theoretically make an engine run slightly leaner. but this guy has a bone stock engine with the exception of 5lbs. of forced induction and an H-pipe. Ford's EEC-4 computer will naturally make a stock engine run at about 270 to 280 pts. on a long term block integrater (Snap-on 2500 scanner)thats the EEC-4's way of using long term engine telemytry to naturally richen the engine. In other words its a built in safe guard to protect the engine in a wide variety of malfunctions that could possibly occur. I just didn't want him to think the H-pipe was causing his problems so he wouldn't over look the more
obvious. Carbon build-up on the pistons or combustion chamber area , or a vacuum leak , or a stretched timing chain with 140,000 miles are more prone problems to cause engine detonation.

[speedytang]

His problem is the stock fuel pump with probably 100k+ miles on it can't keep up even with the FMU and is going lean. FMU is not a magic fix with out enough fuel to block at the return line.

[victor]

thanks guys the motor has 140 thou. but the fuel pump only has about 5-8 thou. lots of carbon build up is a good thought and that may be the problem. I have good vacuum its about 19 psi.

[speedytang]

The pump is new but if it is still a stock replacement your way to small. You need at least a 190 lph pump but for the few dollars more get the 255 lph