Fastest 231ci Buick?

[Chevota]

After reviewing the data log and looking at parts my tune was dead on. No signs of detonation anywhere.

 

[Alky V6]

After reviewing the data log and looking at parts my tune was dead on. No signs of detonation anywhere.

Throughout your rpm and boost range, have you calculated what the cylinder pressures were at every relevent rpm/boost/nitrous point?

 

[Alky V6]

What was your boost to rpm rise? How much nitrous was in the mix during the midrange? What is your static CR?

 

[Chevota]

What was your boost to rpm rise? How much nitrous was in the mix during the midrange? What is your static CR?

N2O was turned off at 10psi by XFI. It was not a factor.

 

[Alky V6]

THANK YOU Scott! You made me revisit something in my upcoming tuneups. You saved me. A tuner needs to know what his/her limit is with cylinder pressures for the type fuel and mixture being used. Unfortunately, you usually need to break something to find or get an idea on that limit. My Vegas blow up gave me some invaluable data on that subject that has allowed me to set some limits.

 

[Alky V6]

N2O was turned off at 10psi by XFI. It was not a factor.

The nitrous was not a factor in my Vegas blow up either.

What was your boost ramp up like, related to your rpm rise?

 

[Chevota]

The nitrous was not a factor in my Vegas blow up either.

What was your boost ramp up like, related to your rpm rise?

1.Foot brake to 3200rpm first bulb- 0psi. 2.Roll into 2nd bulb with t-brake-5psi about 4500rpm. 3. Go wfo with n20. 4. Launch at 20-25psi about 5500rpm. Steps 3 and 4 in about 2/10's. Used a 60-70shot depending on bottle psi.

 

[Alky V6]

1.Foot brake to 3200rpm first bulb- 0psi. 2.Roll into 2nd bulb with t-brake-5psi about 4500rpm. 3. Go wfo with n20. 4. Launch at 20-25psi about 5500rpm. Steps 3 and 4 in about 2/10's. Used a 60-70shot depending on bottle psi.

Let's concentrate on the 4500 to 5500 rpm range where you went from 5 psi to 20-25 psi. Map out an exact graph of what the boost was at each 100 rpm step between those two rpm points.
Also, include at each of those points the fuel mixture strength and the timing setting. What is the static CR?

 

[Alky V6]

Include the exact point that the nitrous shut down.

 

[Alky V6]

What was the octane of the fuel?

 

[Alky V6]

Also, the efficiency level of the compressor during that range and were you icing?

 

[Chevota]

Also, the efficiency level of the compressor during that range and were you icing?

I will have to get back to you regarding the graph and points. The laptop is at the shop with the log. Fuel was q16(117oct), and IAT was 48deg(yes,ice).

 

[Alky V6]

If you really want me to be accurate about this I'm going to need cam specs too. PM or email me them if they're topo secreto.

 

[Alky V6]

I will have to get back to you regarding the graph and points. The laptop is at the shop with the log. Fuel was q16(117oct), and IAT was 48deg(yes,ice).

Oh Boy!! Get all that info to me Scott.

 

[Chevota]

If you really want me to be accurate about this I'm going to need cam specs too. PM or email me them if they're topo secreto.

I'd rather confide in you with the future engine build then focus on the past. The cam was nothing special. 236/232, 114lsa,@50, and around .640lift with 1.65 rockers. You will like the next motor.:biggrin:

 

[Alky V6]

I'd rather confide in you with the future engine build then focus on the past. The cam was nothing special. 236/232, 114lsa,@50, and around .640lift with 1.65 rockers. You will like the next motor.:biggrin:

So far everything is pointing to an excessive cylinder pressure problem. Get me all that info and I can show you what your limit is for that fuel and maybe some things that can be done to avoid a future rod folding incident. It's always best to learn as much as possible from a past incident. Then you're more tuned into what to avoid with the next engine.

If you want, send me as much info on the new engine too, and I'll start putting together a test model for you.

 

[forcedfedv6]

Truck by itself is under 3,000 pnds, it maybe 3,000 with Him on the drivers seat.

 

[Chevota]

So far everything is pointing to an excessive cylinder pressure problem. Get me all that info and I can show you what your limit is for that fuel and maybe some things that can be done to avoid a future rod folding incident. It's always best to learn as much as possible from a past incident. Then you're more tuned into what to avoid with the next engine.

If you want, send me as much info on the new engine too, and I'll start putting together a test model for you.

What software do you use Don?

 

[Alky V6]

Engine Analyzer Pro v3.5 by Performance Trends.
Drag Racing Pro v2.0 by Performance Trends.

They're more than worth the price if it saves you an engine.

 

[Alky V6]

I think Dons is 224ci and weighs around 3300. Not too many guys opt to run a 231 when the classes allow more ci. A really fast 231 would be in the 8.40-8.50 range at 3500lbs. That would basically be a TSO car with a 231ci engine.

The car weighs 3160lbs. fueled, and with me in it. I weigh 165.