STD Tuning Engine overboost protection

overboost protection

overboost protection

 
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bricktron
'77 240D

174
08-28-2014, 11:57 PM #1
on my om617 i have no switchover valve but do have a manual boost controller and pyrometer. i found i could peg the 15 PSI boost gauge and i'm not sure if i should switch to a 30 PSI gauge or turn the boost down! as long as i keep the EGTs in range (say, <= 1100 F), how high do you all think i should set the controller?


english red rat rod 1977 240D, OM617.952 burning B99.9, iron 4-speed & 2.88 diff, 195/60/R14 on alloys, 5mph bumpers, battery in the trunk, 25mm swaybar, 4x ECE H4 lamps, double brake lamps, deleted sunroof, export zoll & california blue plates




bricktron
08-28-2014, 11:57 PM #1

on my om617 i have no switchover valve but do have a manual boost controller and pyrometer. i found i could peg the 15 PSI boost gauge and i'm not sure if i should switch to a 30 PSI gauge or turn the boost down! as long as i keep the EGTs in range (say, <= 1100 F), how high do you all think i should set the controller?



english red rat rod 1977 240D, OM617.952 burning B99.9, iron 4-speed & 2.88 diff, 195/60/R14 on alloys, 5mph bumpers, battery in the trunk, 25mm swaybar, 4x ECE H4 lamps, double brake lamps, deleted sunroof, export zoll & california blue plates




Torkey
Dirty Diesel

220
08-29-2014, 12:21 AM #2
I think your EGTs will be fine. Diesels are different from gas engines in that the more boost you give them the lower the EGTs are. The extra boost might give you a little more HP but you really need more fuel to get the all added performance from the boost.

79 300CD
82 300SD
Dirty Little Freaks Racing
Torkey
08-29-2014, 12:21 AM #2

I think your EGTs will be fine. Diesels are different from gas engines in that the more boost you give them the lower the EGTs are. The extra boost might give you a little more HP but you really need more fuel to get the all added performance from the boost.


79 300CD
82 300SD
Dirty Little Freaks Racing

bricktron
'77 240D

174
08-29-2014, 01:24 AM #3
thanks Torkey. i know about the fuel issue but not sure at what level boost fuel starts to be a bottleneck on the 617.

with regard to the pistons staying intact - the overboost protection was there for a reason, right? (it didn't get carried over in my swap and i'm hoping the MBC suffices.)


english red rat rod 1977 240D, OM617.952 burning B99.9, iron 4-speed & 2.88 diff, 195/60/R14 on alloys, 5mph bumpers, battery in the trunk, 25mm swaybar, 4x ECE H4 lamps, double brake lamps, deleted sunroof, export zoll & california blue plates




bricktron
08-29-2014, 01:24 AM #3

thanks Torkey. i know about the fuel issue but not sure at what level boost fuel starts to be a bottleneck on the 617.

with regard to the pistons staying intact - the overboost protection was there for a reason, right? (it didn't get carried over in my swap and i'm hoping the MBC suffices.)



english red rat rod 1977 240D, OM617.952 burning B99.9, iron 4-speed & 2.88 diff, 195/60/R14 on alloys, 5mph bumpers, battery in the trunk, 25mm swaybar, 4x ECE H4 lamps, double brake lamps, deleted sunroof, export zoll & california blue plates




cho
GT2559V

183
08-29-2014, 03:29 AM #4
hi mate

14psi with unmodified pump is max you need
if you just peg to 15 nothing wrong can happen....I have no OB protection
solenoid also...no problem there.... you can tweak MBC to open tad sooner
so the peak is 14...

cheers

500SEC euro gen II powered by OM617a stolen from 84 300SD .... with 280se transmission now Smile
----------------------------------------------------------
.
cho
08-29-2014, 03:29 AM #4

hi mate

14psi with unmodified pump is max you need
if you just peg to 15 nothing wrong can happen....I have no OB protection
solenoid also...no problem there.... you can tweak MBC to open tad sooner
so the peak is 14...

cheers


500SEC euro gen II powered by OM617a stolen from 84 300SD .... with 280se transmission now Smile
----------------------------------------------------------
.

Torkey
Dirty Diesel

220
08-29-2014, 10:31 AM #5
I agree with cho. 14psi is all you need with an unmodded pump.

I wouldn't spend too much time worrying about damage from 14psi. We've been racing with 22psi boost for 3+ years and haven't had any issues. However, the back pressure is high ~42psi.
This post was last modified: 08-29-2014, 10:48 AM by Torkey.

79 300CD
82 300SD
Dirty Little Freaks Racing
Torkey
08-29-2014, 10:31 AM #5

I agree with cho. 14psi is all you need with an unmodded pump.

I wouldn't spend too much time worrying about damage from 14psi. We've been racing with 22psi boost for 3+ years and haven't had any issues. However, the back pressure is high ~42psi.


79 300CD
82 300SD
Dirty Little Freaks Racing

Simpler=Better
PORTED HEAD

2,127
08-29-2014, 10:34 AM #6
x2 to turn it down a little, once you start making extra boost without fuel you're just throwing away energy

Newbie-read this: Cheap Tricks
617.952-220k-Getting built up
larsalan I guess I need to look at this stupid ass drip shit. What you have to like mess with those elements on the pump? What a fucking hassle. then use some wire to hold the throttle open or some shit?
Simpler=Better
08-29-2014, 10:34 AM #6

x2 to turn it down a little, once you start making extra boost without fuel you're just throwing away energy


Newbie-read this: Cheap Tricks
617.952-220k-Getting built up
larsalan I guess I need to look at this stupid ass drip shit. What you have to like mess with those elements on the pump? What a fucking hassle. then use some wire to hold the throttle open or some shit?

bricktron
'77 240D

174
08-29-2014, 10:12 PM #7
sweet. thanks everyone, i will set the MBC to 14 PSI and enjoy life sans solenoid!


english red rat rod 1977 240D, OM617.952 burning B99.9, iron 4-speed & 2.88 diff, 195/60/R14 on alloys, 5mph bumpers, battery in the trunk, 25mm swaybar, 4x ECE H4 lamps, double brake lamps, deleted sunroof, export zoll & california blue plates




bricktron
08-29-2014, 10:12 PM #7

sweet. thanks everyone, i will set the MBC to 14 PSI and enjoy life sans solenoid!



english red rat rod 1977 240D, OM617.952 burning B99.9, iron 4-speed & 2.88 diff, 195/60/R14 on alloys, 5mph bumpers, battery in the trunk, 25mm swaybar, 4x ECE H4 lamps, double brake lamps, deleted sunroof, export zoll & california blue plates




 
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