Should I add nitrous or lighten up the truck and run without it?

[mtomac]

For the new DHRA heads up class next year:

You can run up to 2 turbos(any size), NO nitrous, and NO propane. The truck must weigh 15# per cubic inch or 5500#, which ever is greater. So I could weigh 6045#.

OR

You can run one turbo(any size), WITH nitrous, but NO propane. The truck must weigh 16.5# per cubic inch or 6200#, which ever is greater. So I could weigh 6650#.

Right now with a 1/4 tank of fuel my truck's race weight is 6600# without the spare tire and tailgate. A second turbo or a bigger single turbo isn't much of an option right now on the Duramax.

So, should I lighten the truck up 500# (which is do-able) and run my current set-up or should I add nitrous to what I have now? I can get a good ammount of smoke by stacking boxes so I'm thinking a mild shot of nitrous (50-100hp) to clear up the smoke would add some decent power without having to worry about o-ringing the heads.

Right now I'm running 12.8's at almost 104mph with the stock turbo, stock injectors, stock fuel system, without nitrous or propane, with just computer tuning, intake(airbox) & exhaust (muffler) mods on the motor. Anyone think the truck would be faster with the current setup weighing 500# less or at its current weight with a mild shot of nitrous?

Bigger injectors and a bigger shot of nitrous would make even more power but I would have to o-ring the heads for sure and I'm not ready for that yet...

[ratlover]

all motor has a nice ring to it IMO. I really dont know diesel performace to know what would be the best route though.

Were you going to shead 500#?

Taking weight off the nose and sheading some unsprung weight would definatly help the 60' times and 60' is were you make up or lose alot of ground.

Wonder if weld makes some 8 lug draglites? Bet she would look pretty slick. Mickey make load range E et streets? :confused: :rolleyes: :D

You look into changing out the 373's?

[Flyboy]

You seem to be the drag race expert here,but I think you should lighten it up first and try it. Do you have bucket seats? You could remove one as well as the back seat. That would get you some lighter. Can't think of what else could be removed that you haven't already removed.

[Max Power]

Peronally I like the all motor approach as well. I think it would be a lot easier for you as well. IMHO it would be a PITA stripping the truck between track and road. Plus then you have the extra get up and go on the road without having to remove your seats before you drag someone from the stop light. ;)

[sdaver]

I say lighten it up............then lite it up :D dave

[ 09-12-2003, 04:02 AM: Message edited by: sdaver ]

[McRat]

Weight is the key.

Lightening a vehicle does what adding power does except:

Easier on the driveline, easier on the tires, easier on the launch, easier on the motor.

Suggestions:

Single battery
lightweight front bumper
lightweight rims and tires
delete AC


Just some thoughts...

[ratlover]

I gota even better idea, how bout buying a reg cab? tongue.gif

I still cant believe you weight that little though. Heck I though my truck would come in close to that and its a reg cab. I thought these trucks were fatter than this.....I mean a tail gate and a spare cant weight that much?

[Kennedy]

Aside from the "Just say no to drugs" thing, there is something to be said about doing it drug free.

Then again, it should be VERY easy to rig up a temporary Nitrous kit and see what happens. Easily reversible. I've got a bottle and some doo dads here, and I've been meaning to do a quickie setup to try it, but likely will do injectors first.

I don't think it's practical to lighten mine up. I'm at 7660 last I checked full of fuel with me in it...

[DMAX Daddy]

How much would a composite bed lighten you up?

[mackin]

My suggestion is to just add the drugs .... Eventually you will, so just get it done .... Start with the pane, then you can mix a little in when you tow your tractors around cooling the EGT's a bit,off the track .....

Dissassemble,stripping your truck reassembling will get to be a pain in the arse .... After all you drive it to the track ....

Mac

[dmaxalliTech]

Hey Mike, we could take off the box, I have a few 2x4's we could use if you need to haul something, then we can take off the doors, maybe you should unhook the trailer that you tow your competition on.. LOL Thats the only way most of them can keep up!

[mtomac]

I was thinking of removing my goosneck hitch, receiver hitch, rear bumper (replace with rollpan), back seat (crew cab), and one of the batteries to get about 500#

I think the composite bed isn't much lighter than the steel one. I remember reading somewhere it was only 50# lighter.

I could just take off the bed but that would look silly, I don't really care for the cab & chassis look.

Propane is not allowed in the heads up Pro Street Class.

I would like to get the truck in the low 12's. I'm not sure if lightening it up 500# will do it. Likewise I'm not sure if I have enough unburnt fuel to get in the low 12's with nitrous. Maybe I'll just lighten up the truck first and see how fast it will run.

[Amianthus]

Doing whatever you have to do to try to get ahead of me, eh John? tongue.gif

New injectors, good lift pump, and twin turbos for me. You've got your work cut out for you. Oh, and I still have my LP on tap. :D

Just don't even think of getting me out on the track. With 300# more engine and at least 800# of other stuff, I couldn't even qualify let alone race in the DHRA. Not weighing in at a "svelt" 8200#. Although, if I take off every other lug nut... :D

BTW, Michael, get the Nitrous. You'll be facing people that WILL use it to win. You can always lighten it later.


Originally posted by kennedy:
Aside from the "Just say no to drugs" thing, there is something to be said about doing it drug free.

Then again, it should be VERY easy to rig up a temporary Nitrous kit and see what happens. Easily reversible. I've got a bottle and some doo dads here, and I've been meaning to do a quickie setup to try it, but likely will do injectors first.

I don't think it's practical to lighten mine up. I'm at 7660 last I checked full of fuel with me in it...

[zip]

I thought I saw an add on the TS Performance site where they said you didn't have to re-ring with their NOS kit. Some pretty awesome HP increases too.
http://www.tsperformanceproducts.com/gm/nos.asp
zip

[WhiteDuramax]

12.8 isnt fast enough for ya Tomac??? lol I finally ran my truck at IRP in Indianapolis. My fastest time was 14.9 running Predator only and weighing in around 7200lbs. I talked to a guy there that seems to be pretty big in the DHRA now, he is from circleville, In i believe, he has an 01 Dodge, Quad dually, he was practicing to get consistent, his fastest was a 14.6, but he had, box, injectors,tranny, and a hx40.

[mtomac]

At some point with enough nitrous you will need to o-ring the head(s) on any truck with a nitrous system. I'm thinking about using just enough to clear up the the exhaust from a stacked combo so I shouldn't have to worry about o-ringing it yet...

Single or Dual stage nitrous, which would be better for a smaller shot (50-150hp)

I'm just getting started. I'm waiting for our favorite big HP tuner out of TX to release a bigger aftermarket turbo (comming soon). Then I'll have to russle up a bigger set of injectors, pull the heads to o-ring them and while I'm at it do some head work for increased flow. Then I can hit it with a couple big shots of nitrous. At that point I'll need to add a roll cage, racing seats and a 5 point harness.

[More Power]

Hey MT,

I'm curious why the DHRA added weight restrictions?

I'm assuming this was to keep the class(es) open to the "average" diesel pickup owner.

Twin turbos (one for each bank of cyls) should really add a lot of power without increasing fuel/boost. The V-mounted turbo is a significant exhaust backpressure bottle-neck. Works well for packaging and for most normal uses, but.....

MP

[ 09-13-2003, 06:19 AM: Message edited by: More Power ]

[king D]

[QUOTE]Originally posted by Micheal Tomac:
[QB] At some point with enough nitrous you will need to o-ring the head(s) on any truck with a nitrous system. I'm thinking about using just enough to clear up the the exhaust from a stacked combo so I shouldn't have to worry about o-ringing it yet...


mike i think as long as you keep your shots down below 200 hp that o ringing isnt a major concern,it was my impression that o ringing is needed mainly when going to twin comppound turbos and the extra boost they produce,i could be wrong just my assumption...jess

[mtomac]

nitrous will increase cylinder pressure

[WhiteDuramax]

Hey Mike, did you talk to Clint about a bigger single yet, rumor is on there forums is that one is being tested right now and should be out soon.

[JoeyD]

Go with the Nitro.
Does anyone know if Clints truck blew the motor or had any motor trouble. I was reading somewhere it had some trouble.

[Joe.G]

Advice: 100 lbs off your weight equals 1/10 of a second in the quarter mile. If you are running 12.80 in the quarter and drop 500 lbs, then you should be able to run 12.3. This works, believe me!

[mtomac]

Joe.G, I know the 1/10 second per 100# formula works on cars but does it work on these trucks? At some point increased drag and wind resistance against the less than ideal aerodynamic shape and large square inch surface area of the truck will start to work against it. I think a lighter truck would only be so much faster to a point. At that point more hp will be needed to push the truck faster.

[ 09-15-2003, 04:35 PM: Message edited by: Micheal Tomac ]

[Big_Blue]

Originally posted by Micheal Tomac:
nitrous will increase cylinder pressure As I am getting ready to install my PS2000 and am already thinking about nitrous. What is the stock cylinder pressure and how much can it take? How much do each of these mods add alone and combined?

Thanks

Brad

[mtomac]

traction problems? so far with 4wd and a set of BFG AT's there have been no traction problems

[Elowe65]

Mike L.

Is that the truck that was at Palmdale???

Rolling Big Power (rollingbigpower.com) has a 2wd stake bed that runs some decent numbers at Irwindale.
Talking with the main guy at RBP, he says GM directly, did work on their trans for testing purposes. Trying to find more info on that.

I wish I had a trans that would hold up to all the power I have in the garage (NOS, LP, slicks, etc.)... Just need to come up with funds.

Tomac, good luck on your quest. McBride tells me your hardcore...12.8's definitely sounds like you are.
I'd go for the spray. You can go fast, but you can always go faster with oxide....

[a64pilot]

Michael,
The .1 for 100# rule works for a 3,000 lb. car, for a 6,000 lb# truck I think it's more like 200# for a tenth. But as you know lite makes right. I don't know of a two stage 50hp shot, 50 is really small.
Something you might want to try, as you know N02 is just more air to the motor, like boost is. I think that any problems you might have would come from too much N02 while at high boost. How about launching with a 100 shot then dropping to a 50 shot at say 25 psi or so? I know this is backwards from gas engine practice, more RPM = more N02. My only experience with N02 similar to this was from building turbo drag bikes about 25 yrs ago. We would use the N02 until the turbo built boost to try to eliminate turbo lag, the motor wouldn't stand boost and N02.
BTW I'm for lightening and running N02. of course it's not my truck on the line, and anybody can be an arm chair quaterback :D
Good luck, I'm rooting for you, low 12's will be hard IMHO, but I'd bet money that a 12 sec pass with only programming wasn't possible either until you did it.

[zip]

a64pilot- Is the reason for re-ringing the heads due to too much gas trying to get out of the engine and having nowhere to go?
zip
By the way,MT-hope you can do this thing without gas. Man that would open some eyes.

[a64pilot]

Zip,
The stock cyl. head gaskets failure point was lower than the peak cyl. pressure so the gasket would blow out. On the bikes the answer was to cut a ring in the top of the cylinders 10 thousands deep and tap 20 thousands copper wire in it. That combined with a solid copper head gasket would hold up to 25 lbs of boost with a 8 to 1 compression engine. Sounds low compared to our diesels dosen't it?
The failure point of the engine on the bikes was the crankshaft. The old Kawasaki's used a roller bearing crank that was pressed together, first they would twist so we welded them. Anyway with the N02 and the turbo spooled the cranks would break.
Eventually with all motors there is a weak point, usually it's the rods or the crank. I'm amazed that the Dmax has held as much as it has. People like King D have I believe basically doubled the power output and haven't found it yet, but they may be close :D
Sorry about rambling it's just I really like high performance stuff.