Question: Built Motor & Trans How Much NOS Can it Safely Take

prostreeter600

Street rodder
Jul 18, 2010
893
7
18
Dallas Tx
Hoping someone on here has gone where I’ve yet to go . So far I have sprayed it with a 62 jet thru a Zex Solenoid that came with my 300 HP Zex Diesel NOS System which their chart says a 62 jet will give me 150 HP . I gained a tenth in the 1/8th with the 62 jet which netted me my best ever 1/8th at 6.19 straight fuel it ran a 6.29 which is also a best on straight fuel . I want to put the truck in the 5.90s with NOS but not at the risk of blowing it up . My Sig shows everything that I’ve got . What is the biggest NOS jet and or systems that anybody on here has personally run on a built engine . On my 6.19 with 62 jet run there is still extra fuel left to be burned off so at this point I’m tempted to throw the kitchen sink at it and run a 125 jet which shows to give it a 300HP boost if the extra fuel is there obviously. I’m also hoping to put it in the 1.3s 60’ . Any help would be appreciated. Thanks in advance for your help .
 

Evan@InglewoodTrans

yerp
Vendor/Sponsor
Aug 5, 2010
3,118
65
48
39
Western MA
There is no answer to your question with the level you’re already at without the nitrous even anything can and will let go unfortunately on any given pass. The majority of trucks haven’t even made it through what you’ve already done.
 

Chevy1925

don't know sh!t about IFS
Staff member
Oct 21, 2009
21,065
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Phoenix Az
call your engine builder. it will depend on piston to wall clearance and piston to head clearance. If your still on the stock crank and stock block, i dont see it being able to hold much more reliably. if you dont mind pushing it till it breaks, i would bet 300-450 shot could be had assuming the pistons had the clearance.
 

S Phinney

Active member
Aug 15, 2008
4,011
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28
Quncy, Fl
Running the pistons you are they should have .008 or better depending on how loose he set it up. You should be fine with those clearances. Piston to head would be something to consider but I don’t see him setting it up with less than .030 quench. Anything can happen but I think you could use more than you have without any more damages than you are already playing with.


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prostreeter600

Street rodder
Jul 18, 2010
893
7
18
Dallas Tx
Everything being said sounds logical. I would not be maxing it out every time out just when the need arrises . I just wondered if the lower compression ratio played into the equation at all .
 

S Phinney

Active member
Aug 15, 2008
4,011
18
28
Quncy, Fl
It does play into it. That’s adds a little more cushion on cylinder pressures. Have you did a compression test to see where the static compression number is at?


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Chevy1925

don't know sh!t about IFS
Staff member
Oct 21, 2009
21,065
4,736
113
Phoenix Az
Everything being said sounds logical. I would not be maxing it out every time out just when the need arrises . I just wondered if the lower compression ratio played into the equation at all .

Its just one part to a whole equation but the lower CR helps
 

JoshH

Daggum farm truck
Staff member
Vendor/Sponsor
Feb 14, 2007
13,582
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Texas!!!
FWIW, I ran two stages of spray, an .062 and an .051 jet, on a totally stock LBZ.
 

prostreeter600

Street rodder
Jul 18, 2010
893
7
18
Dallas Tx
I have not done a static compression test . Josh the difference might be that I was already seeing 85–100# of boost on straight fuel . I did not check it on the NOS run . I’m gonna hit it with more next time out and watch the boost gauge. :D:D
 

torqued2dmax

Member
Mar 26, 2017
646
1
18
Brookville, PA
Had a wastegate on it initially, nothing but problems with leaks . I did away with it . Haven’t had one on it for a good while .
It is great reading your posts and the fact that you have figured how to make these slugs go faster than about 90% of the people on here is amazing , keep up the great work in helping us learn from your testing ! I will never have a truck as fast as yours but it is fun watching your progress over the years ! Good luck and thanks !
 

prostreeter600

Street rodder
Jul 18, 2010
893
7
18
Dallas Tx
I appreciate the kind words Torqued2dmax. I’m just out to have a little fun on occasion to get that adrenaline rush . I have 2 street rods in the garage as well , 1 I’ve had running before and it never went as fast as this Diesel on my Sig . It’s a ton of fun blowing the doors off these gassers . I’m wanting to push the truck to a 6.0 or 5.9s . We shall see if these tracks stay open a little longer into the year