Opps Overboosted

[HelloBozos]

I, Under WOT had the factory rubber boost line slide off the factory metel boost line, I saw 26psi boost out of a gt-71 on stock block steel head gaskets. The XFI cut the motor but not quite soon enough through one my bad karma moments.(the XFI was at max boost)Before i had piston pin come out,I'm guessing on the dyno with it being new the reason for me sleeving number 4 cylinder.After the line came off,I'd loose all the radiador fluid in 20 minutes of drive time,the car still had all it's power an had no leaks anywhere. What i did was Cracked the sleve...8^(...going chrome molly or new block if it is damaged.I'll have to take my billet mains out this one into a new one if i have block damage

 

[lilredss0287]

26 psi is considered over boosting for a stock engine? i figured around 30+ would be to much

 

[FastB]

I have a stock engine and hit 26#'s often..and it's even seen 28#'s a couple times with no knock..but I do have alky.

 

[Amelio]

ouch that sucks! so you did this on the dyno? or had hurt it before the dyno then sleeved it and hurt it again?

I always say any boost level can be "over boosting" if you dont have the correct fueling.

 

[HelloBozos]

Did this on the street,Hooked the line back up an drove home,I lost the pin on build before this one on the dyno,Then the sleeve went in

 

[HelloBozos]

Alky here to, GT-71 Persion turbo with 72inj.,RJC front mount, Custom XP R1 pump hot wired,stock block,steel mains, gn1 heads,steel head gaskets..psi is what i saw, could been more, was enough to crack the sleeve though...all by not 2 cent wire tieing the boost line on..8^/

 

[pdzz]

Alky here to, GT-71 Persion turbo with 72inj.,RJC front mount, Custom XP R1 pump hot wired,stock block,steel mains, gn1 heads,steel head gaskets..psi is what i saw, could been more, was enough to crack the sleeve though...all by not 2 cent wire tieing the boost line on..8^/

This is overboosting!!! Looks like the top of your piston is showing signs of detonation. I did this on C16 and 30psi plus!!! My bad too, had my gate set-up wrong... Live and learn. Phil.

 

[TurboBob]

Alky here to, GT-71 Persion turbo with 72inj.,RJC front mount, Custom XP R1 pump hot wired,stock block,steel mains, gn1 heads,steel head gaskets..psi is what i saw, could been more, was enough to crack the sleeve though...all by not 2 cent wire tieing the boost line on..8^/

you hit fuel-cut in the XFI with alky flowing?


There's your problem.....


Bob

(but shame on you for cheaping out on the tie-wraps.....)

 

[bison]

Having that line off with a turbo like that with low backpressure will resulting 35psi before you can blink. You saw 26psi on the gauge. Actual was likely approaching 40psi. Check for bent connecting rods

 

[TurboBob]

................... Actual was likely approaching 40psi. .................

now that could be a problem too......

B

 

[GNVenom]

Little too much boost:

Cracked Head

 

[Phoneguy]

Here is mine, way past 30psi on 93 and ALKY. Boost controller went crazy...

 

[HelloBozos]

View attachment 145517This is overboosting!!! Looks like the top of your piston is showing signs of detonation. I did this on C16 and 30psi plus!!! My bad too, had my gate set-up wrong... Live and learn. Phil.

Water was spraying in that cylinder reason for all the discoloration, others are fine. I was running 93/alky an set 22psi of boost. You Massivly over boosted! My XFI saved me ,sort of, If i had it set correctly, My motor still be in the car...8^(

 

[HelloBozos]

Having that line off with a turbo like that with low backpressure will resulting 35psi before you can blink. You saw 26psi on the gauge. Actual was likely approaching 40psi. Check for bent connecting rods

Yeap having everything checked, This only thing found visuly so far,Updates to follow.The car Ran Great after,just loss water.The actual dead on boost i created would be the max limit you can set on the XFI.

 

[HelloBozos]

you hit fuel-cut in the XFI with alky flowing?


There's your problem.....


Bob

(but shame on you for cheaping out on the tie-wraps.....)

I hit the max boost limit cut-off on XFI. It Cut the ignition,Everything is being checked,It has the stroker kit.The car still ran Great after (less water loss),I smoked twin super-charged BWM m5 the next day on top end.I'm hoping just new sleeve,I'll update whats found next..;^)

Enjoy!

 

[TurboBob]

I hit the max boost limit cut-off on XFI. It Cut the ignition.........

Thats not good if you are running a stock ignition system, as it will desynchronize the ignition system and you could get up to 5 cylinder events firing the wrong cylinder when the xfi re-enables the ignition output.

 

[HelloBozos]

The Thottle went dead tottaly,i guess my set-up cut ignition an fuel all at once.I cut the key off an stopped,fired it back-up an sounded like big cam big block, i then popped the hood,found the factory boost line off, hooked it back up, re-fired the car, an it was fine. (Less the now cracked sleeve)I think my bacon was saved this round

 

[Amelio]

here is mine, way past 30psi on 93 and alky. Boost controller went crazy...


View attachment 145518

holy crap!!!!!!!

 

[HelloBozos]

I not only cracked the sleeve, i cracked the block!!!



New block on order