[German Engineered]

I'm doing a buildup of an ABA short block for my 92' digi 8v. I want to run nitrous, but I was wondering who has blown the most with a built bottom end? I'm not planning on getting too crazy, but I would like to safely run 75-100 shot. If anyone has any details that would be great. Oh, by-the-way, If you can include the specs on your motor that would also be helpful!
Thanks
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[gearhead455]

Re: How much NOS has anyone blown? (German Engineered)

I'm about to blow in 80HP "wet" worth but it should take 100 - 120HP safely. Need to use an N20 activated ignition retarder or knock the base timming down 2 degrees. Also need 100+ octane gasoline. I calculate that the CIS pump should be up to the task.
I recomend using a fuel pressure cut-off switch, and N20 systems that are wet for safety.
Stock rods, crank, ballanced with ARP rod studs. 10:1 Cast pistons but may need forged for a bigger shot. 40X33 head, crane 272, headder, lightened F wheel, bla bla bla....

 

[German Engineered]

Re: How much NOS has anyone blown? (gearhead455)

I was thinking about going with a lower compression ratio to reduce the amount of detonation. I figured that the few horse power that I would loose due to the lower compression will be non noticeable. If I reduce the ratio then I will be able to run pump gas without a problem. I though about not messing with it but I figured that the cost and the availibility of the fuel would be too much of a hassel. The motor will have a ABA short block with polished rods, forged pistons (Velocity) and ballanced everything. The Head is in the process of an extensive P&P with a Autotech G Grind, TT springs, stock followers, valves turned and polished with port matching all around. The Intake is being ported as well as the Exhaust manifold, but the Exhaust manifold id going to be high polished for less carbon buildup. I figure I would go with ARP for the whole engine for safety sake.
Thanks for the info.
Keep The Advice Comeing
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[German Engineered]

Re: How much NOS has anyone blown? (German Engineered)

By the way, cool looking Rabbit!! http://****************.com/smile/emthup.gif

 

[raylomas26]

Re: How much NOS has anyone blown? (German Engineered)

When I monkeyed with the non adjustable 125hp plate in my Chrysler 300 (383 bigblock) I experienced one or more ground straps on the spark plugs glowing red hot as indicated by a car shaking backfire through the intake and completely mangled air cleaner. At 75-100 hp, consider 1 step lower heat range in spark plugs
Lou

 

[cthulu703]

Re: How much NOS has anyone blown? (raylomas26)

I haven't blown any N2O, but I've sucked plenty of it.

 

[German Engineered]

Re: How much NOS has anyone blown? (cthulu703)

Bump!

 

[German Engineered]

Re: How much NOS has anyone blown? (cthulu703)

Bump!

 

[gtibunny8v]

Re: How much NOS has anyone blown? (German Engineered)

With forged pistons the 100 shot would be fine (I hope this is a wet kit). Just use colder plugs and retard timing on pump gas. After the first time you use it pull the spark plugs and look and see if there are any specks of silver on them. If not then your good. If you do then retard the timing some more. I dont see needing to lower the compression. I used a 50 shot wet in a stock ABA, stock chip for timing and one step colder plugs.

 

[rbr20]

Re: How much NOS has anyone blown? (German Engineered)

I ran a 75HP shot and went through two 10LB. bottles worth of juice, with no problems. Bump it up to a 100 Hp shot and after 5LBs. lost my head gasket. But after taking the head off found out that it had a cheap head gasket. Pistons valves look great with no sign of detonation. On the 100 shot I pulled out 4 deg. and on the 75 shot 2 deg. of timing. Both times I was running 110 octane fuel. As far as the rest of the engine goes its 11:0 to 1 comp. cast pistons stock bottom end 1.8L 8V. One more thing to look at is your clutch N2O is instant torque and very unforgiven.Good Luck.

 

[German Engineered]

Re: How much NOS has anyone blown? (rbr20)

Bump!!!!!!!

 

[German Engineered]

Re: How much NOS has anyone blown? (German Engineered)

More information needed.
Thanks
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[gearhead455]

Re: How much NOS has anyone blown? (German Engineered)

What else woud you like to know? The bottom end will hold together just fine with a 200 HP shot with ARP fasteners. That is not the issue, what your worried about is melting down the pistons, lifting the head and detonation. The "safty part" is installing the kit correctly. Making sure all of the fuel pressures and n2Ojet/Fueljet ratos are correct. And making sure the ignition is retarded according to HP. Most likely if you squeez more than 160 HP into it will gernade the trans / blow head a gasket and may melt down some pistons (if not forged), before the lower end comes apart.


[Modified by gearhead455, 9:19 PM 2-14-2002]

 

[viciousvento]

Re: How much NOS has anyone blown? (cthulu703)

I'm runnin a 75 wet shot & everything has been fine

 

[Vwsport.com]

Re: How much NOS has anyone blown? (viciousvento)

on my 2.0 16v I have ran a single 50 direct 80 and now direct 100 so far no problems. its running old CIS, stock compression (10.8:1??) stock spark plugs (didn't find colder ones fast enough) and stock timing w/ the knock box. I guess I was lucky I didn't break anything, but yes be sure to get a better clutch, it was sliping every now and then. I used it in 2,3, and 4th. I also once used it at 2.5k rpms (I didn't know too much at the begining) but vw engines are nice and strong. I also used my a/f meter and egt meter to keep an eye on things. it never went out of the rich area.
Dan