Injector Question

[Rick539]

We are currently in the buliding stages of my son's 6bolt. The current engine he is using needs the injectors replaced. I have a set of new 650's that is going on his new setup. Will be controlling with a MAFT. Can we use the 650's on the current stock engine with the MAFT and tune them down some. It would save him a few buck from having to buy a new set of stocks to only use for a couple of months. Thanks for any input.

 

[xveganxcowboyx]

Should be just fine using MAFT. I run ~620cc injectors using only MAFT. Works fine. Just be prepared to fine tune it some. You probably won't be able to get away with just setting the thing for 650 and leaving it.

As with any similar compensation that high you may see some higher timing advance, but others get away with it all the time.

 

[Spoolin98]

If I remember correctly, the MAFT manual has information in there on how to set it up to use it with different size injectors. Do you have a datalogger to tune with?

 

[Street Surgeon]

Ah, are there no dsm'ers around your area that would lend you a pair for the break-in period? Those injectors are really common around here just sitting on shelves etc.

 

[Spoolin98]

Oh and to answer your question, you can use the 650's on the current stock engine, that will be fine. I suggest using 450's to break in your new motor.

 

[JayRolla]

Why use small injectors to break the motor in???

 

[Spoolin98]

Well from my understanding, you want to break a motor in under stock boost. You don't need larger injectors to run stock boost.

 

[fourreGsixty3]

Never heard of a MBC? And since when do injector's raise your boost level's. Use what ever injector's you want for the break-in, but make sure you have a way to tune the car.

 

[xveganxcowboyx]

Never heard of a MBC? And since when do injector's raise your boost level's. Use what ever injector's you want for the break-in, but make sure you have a way to tune the car.

Exactly. Using 650's or hell, 1000cc injectors will not change your ability to run stock boost. It just means you'll have room to turn it up L

 

[Spoolin98]

Never heard of a MBC? And since when do injector's raise your boost level's. Use what ever injector's you want for the break-in, but make sure you have a way to tune the car.

First off, when did I say injectors raise your boost level? I didn't, if you want to correct me because you think your way is better, thats fine, but you don't need to be a dick about things.

And by the way, Jackson Auto Machine is the company who told me to break my motor in under stock boost with the STOCK INJECTORS. I'm going to believe a reputable shop that broke in many motors over someone like you who I don't even know. If you would like me to call them to find out exactly why, I will.

 

[dnhieu]

first, this guy is the coolest dad ever!

second, the reason why they say stock boost, and stock injectors is so you dont run rich during break in. the first few hundred miles of a motors life is needed to let the piston rings. if you run rich during this stage you run the risk of washing your rings way (very bad)...

i wouldnt advise running 650cc injectors for the break in unless you have a wideband. this will let you know your correct afr and allow you to lean the car out so you dont wash the rings away...

hope that helps
david

 

[Spoolin98]

first, this guy is the coolest dad ever!

second, the reason why they say stock boost, and stock injectors is so you dont run rich during break in. the first few hundred miles of a motors life is needed to let the piston rings. if you run rich during this stage you run the risk of washing your rings way (very bad)...

i wouldnt advise running 650cc injectors for the break in unless you have a wideband. this will let you know your correct afr and allow you to lean the car out so you dont wash the rings away...

hope that helps
david

Thank You...This is from the break in sheet I was given: "Your new engine must have proper spark and air fuel mixtures to prevent cylinder wash down and or detonation".

 

[TSIMonsteR]

I wouldn't break in a freshly machined motor on nice injectors or a nice turbo. Little metal shards from the machining process can reek havoc on turbine blades and injector heads. Grab a cheap 14b and some 450s for the break in. It will be good to have the 450s around for a backup anyhow.

 

[dnhieu]

I wouldn't break in a freshly machined motor on nice injectors or a nice turbo. Little metal shards from the machining process can reek havoc on turbine blades and injector heads. Grab a cheap 14b and some 450s for the break in. It will be good to have the 450s around for a backup anyhow.

good info ^^^^^. i forgot about using a small turbo for break in also. yeah a new motor can destroy a new turbo...

 

[selmerguy]

I dont think the motor is fresh, reading his first post. It sounds like the "build" is bolt ons. And IMO if you are using lager injectors and not tuning them with a wideband monitoring afr, you are wasteing you time. Running a stock setup during break in is fine, however the stock ECU runs pretty rich and you still risk ring wash. If you have the capibility to tune then go ahead and run the 650's.

 

[Spoolin98]

I wouldn't break in a freshly machined motor on nice injectors or a nice turbo. Little metal shards from the machining process can reek havoc on turbine blades and injector heads. Grab a cheap 14b and some 450s for the break in. It will be good to have the 450s around for a backup anyhow.

I agree also.

 

[Spoolin98]

I dont think the motor is fresh, reading his first post. It sounds like the "build" is bolt ons. And IMO if you are using lager injectors and not tuning them with a wideband monitoring afr, you are wasteing you time. Running a stock setup during break in is fine, however the stock ECU runs pretty rich and you still risk ring wash. If you have the capibility to tune then go ahead and run the 650's.

I understand what your saying, but what will you run richer with? 450's or 650's, the answer is obvious. Now if you had a freshly built motor, it would be a lot easier and smarter to break it in with 450's and not have to tune the motor during the break in period. The initial startup and break in is most important, IMO, its not worth taking the chance of running too rich for the initial break in.