pump timing?

H

hotrod250

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Joined
Sep 4, 2010
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Just wondering how much advanced pump timing people are running with similar mods. I've got a good idea on how to do it; just want to get a idea on where to start.
 
16-18 is a good setting for a light modded street truck. I wouldn't go much over 18 if you do not have the head studded/over torqued and o-ringed. Just remember the higher you go, the more turbo lag you will have, but with a stock hx35 it shouldn't be too bad.
 
I set buddies trucks at 18*, I set my daily driver around 20*. I can't have buddies with faster trucks than me!
 
Big Blue24 said:
I set buddies trucks at 18*, I set my daily driver around 20*. I can't have buddies with faster trucks than me!
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Do you have stock bolts/hg on your DD? Mine is all stock but I want to bump the timing, I was thinking around 18 but was worried about the stock gasket and bolts.
 
kino_fab said:
16-18 is a good setting for a light modded street truck. I wouldn't go much over 18 if you do not have the head studded/over torqued and o-ringed. Just remember the higher you go, the more turbo lag you will have, but with a stock hx35 it shouldn't be too bad.
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i always though the higher you advanced the timing the faster it spooled? i thought thats why everyone advanced it?
 
Gasoline Sucks said:
Do you have stock bolts/hg on your DD? Mine is all stock but I want to bump the timing, I was thinking around 18 but was worried about the stock gasket and bolts.
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I have stock gasket with stock headbolts torqued to 145 ft lbs, never loosened just torqued up in steps of 5 ft lbs with an initial start of 120 ft lbs. Some moved at 120, some didn't. By 130 ft lbs, all bolts were moving on each torque step.

TRUBBS said:
i always though the higher you advanced the timing the faster it spooled? i thought thats why everyone advanced it?
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Higher timing slightly reduces bottom end torque+horsepower and slightly increases top-end torque+horsepower.

Higher timing means the fuel is injected earlier in the cycle. Earlier fuel burns sooner and therefore more completely burns before going out the exhaust system. Late burning fuel in the exhaust system helps to spool the turbo on the bottom end.

As RPM increases, there isn't sufficient time to fully burn most of the fuel before the exhaust valves open. Advanced timing gets the fuel into the cylinder earlier thereby giving it more time to burn before the exhaust valves open, this is how increased timing increases power.
 
I'm at 19 and change. It rips from 2700 on up, but there's definitely a loss in bottom end. I'm running a new head casting, stock headgasket, untouched block, stock bolts and stock torque on the bolts. Have seen 70+ drive pressure and 50+psi boost. (not ideal numbers, I know, still tuning the vgt setup) I think in 'normal driving, 16.5* was more fun overall, but having the ass-end come unglued above 3200 in 4th is pretty damn sweet....I read on here that you're missing out on the fun of a p-pump if running stock-ish timing with 4k springs. I'm a believer now:)
 
truck in sig is daily driver. I had it at 16.5 for almost 2 years it worked out good.
 
i drive 16,5
last summer i have 21 timing.
what temperature you are there in the winter.
Higher timing means bad starting cold days
 
18 degrees in mine. If I had the setup hotrod250 has I'd go with 16-16,5. Good overall performance, I had the timing there before I installed the twins and all the related stuff. Fast spooling and good performance with the HX35. 40psi max.
 
21 last year on the old motor, Now 24 on stock bolts re torqued.

Mods: 4k gsk, Airdog150, DDP 90's, super hx40, no plate, afc mods, racked barrels, 60lb springs, stock delivery valves

Last year this setup produced 456 hp on the same injectors that were pretty out of whack. Now I have a cam, 24*, newer motor, and the injectors freshened up. Hopefully that puts me over 500

Hope that helps you decide
 
I've always generally set trucks to 16.5 17 and never heard a complaint....a buddies got his at like 25 and its a bear to start in the cold
 
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