So, I had my shop build, install, and tune a new 408. Drove it for about 1000 miles before having them do a nitrous tune with a 150 wet shot using a plate system. Broke multiple pistons on the dyno. Turns out the injectors were dirty, at least that's the explanation they are providing. Since they are trying to do the right thing by taking care of me, I decided to have them rebuild the 408 which is being installed soon. I agreed to pay for parts. Do think that's reasonable and fair? Am I being too nice? Have been a customer here for years and they've always done a decent job up until now.

No need to tell me to find another tuner, I have already done that and plan to take the car there as soon as I get it back.

 

Oh wow that sucks So if the injectors were clogged how come it didn't show up when the tuned it n/a?

 

That sucks, but I guess I fail to see how it was the dyno shops fault. If all you did was dyno the car there, why would they be liable? Sounds like your issue should be with whoever did the engine work or the tuner.

Edit: From reading it again, it sounds like this shop did everything? I'd find another shop if I were you.

 

Not sure why it didn't show unless the tune compensated for the clog? My other question is that since this was a wet shot why didn't the fuel side of the nitrous system prevent damage even if there was a slightly lean condition caused by the injectors?

 

They have a machine shop that does the short block and they take it from there. But in the end, I am paying them for the whole package.

 

Sounds like they fucked up in the tune, or jetting..or something, and gave you a line of BS to cover their ***..

 

I'm sorry to hear that happened to you. I agree someone screwed up and I highly doubt it was a dirty injector. What were the air/fuel readings on the dyno run? What about timing?

 

LOTS of unanswered questions, but one possibility is the engine limiter was hit before the nitrous limiter. You can imagine 150hp fuel for 700hp combo is lean. Do you know what the engine and nitrous limiters are at?

spark advance? plugs used? plug pic? fuel type? AFR during n/a and nitrous run? datalog? scan of OBD2 port for problems? fuel solenoid verified as working? jetting? line pressures fuel and nitrous...

 

Sounds like they are blowing smoke up your BUTT

 

Maybe you should go forged this time lol

 

Forged wont make a bit of difference if whoever is tuning this thing, hasnt got a clue how to.

I put my buddys Z28 together last year, cam only 853 headed stock bottom end car...and its made just south of 675rwhp and had 20 bottles through it...not a single issue.

My Hugger orange vert was smacked with 250 all the time, never an issue.


I plan on spraying 400+ at my SS, and going after the stock internal nitrous record....

forged parts are just going to hurt the pocketbook more when this builder/tuner grenades this guys **** again. The labor for an engine build/tune isnt that crazy...Id be getting my **** OUT of there...and going somewhere else.

 

I was just teasing lol

 

How did multiple injectors clog all at the same time? I can see fuel pump failure or regulator take out more then one piston but not multiple injectors to clog at one time. Like every one els said, make them give you a tune file and data log and post it up here.

 

Sorry to read about your engine issues. I'd be curious to see the tune/log files if you're willing to relay them.

 

I'll just say that it is really hard to hurt an engine on the dyno.
The pulls are so short and you never get the true load the car puts on an engine.

I'd probably find a new builder and tuner.

Just sayin.

 

Can we get some info on the tune up? What jets were in it? how much timing pulled? Where were you pulling fuel from? What spark plugs were in it? Also, do you have an aftermarket fuel pump?

 

All great questions, many of which should have answered before spraying but I don't think they took the time to check it.

 

I'll post the NA tune this weekend, I doubt it was changed much before running the car on the dyno. As far as the log, somehow I doubt I'll ever get ahold of it... Nitrous/fuel jets were 62/33. I am running a Walbro 255 in tank pump. Injectors are 42lb. Not sure about plugs and I don't know how much timing he pulled before spraying, but will see what I can find.

The motor let loose at about 5200 RPMs and never hit the rev limiter. Nitrous is a window switch that I believe was set at 6200.

This is a forged motor for someone who asked in a previous post.

 

How much power did it make on the motor?

 

Right around 400 at 6k rpms on a conservative dyno. I was running 11.5 quarters NA.