9.281 @ 146.99
- Thread starter Alky V6
- Start date
I think you're right Bob. That weekend at Vegas, when I did this timeslip run, it was the first time out with a new combination of turbocharger, wastegate, and using the nitrous for initial spool up. The first run of the weekend was with the boost level set at 20 psi. Mind you, this was the first run with a new tuneup combination. The time was 9.726 @ 142.22. To say I was surprised is an understatement. The second run was with a boost level of 21 psi. The time on that run was 9.376 @ 145.2. I increased boost one psi and gained that much time? Again, to say I was surprised is an understatement. The third run produced the timeslip for this thread. It was with a boost of 22 psi, with the boost becoming erratic at high rpm and steadily dropping to around 20 psi by the end of the run. I had hit my rev limit by around 3/4 track and spent the last quarter PRAYING for the finish line.
I am certain that with a change in tire size or gearing AND a larger turbo, and better track weather, this thing is in the eights.
I am certain that with a change in tire size or gearing AND a larger turbo, and better track weather, this thing is in the eights.
Exhaust system
Designed and built by DRW
Flanges supplied by ATR.
Tubing supplied by Burns Stainless. Material 304 stainless.
Primary tubes are equal length at 29"
1.625" ID for 10". Stepped to 1.75" for a total length of 29".
Burns Stainless merge collectors with turbo slip joint provision.
Collector size 2.125" for an average length of 6", dumping into the turbo.
One bellows joint supplied by Innovative Turbo Systems.
Thermal wrapping used.
Designed to provide easy access to the spark plugs and the valve covers.
System tuned with the heads, cam and intake to provide maximum effect between 5,000 to 7,800 rpm.
Designed and built by DRW
Flanges supplied by ATR.
Tubing supplied by Burns Stainless. Material 304 stainless.
Primary tubes are equal length at 29"
1.625" ID for 10". Stepped to 1.75" for a total length of 29".
Burns Stainless merge collectors with turbo slip joint provision.
Collector size 2.125" for an average length of 6", dumping into the turbo.
One bellows joint supplied by Innovative Turbo Systems.
Thermal wrapping used.
Designed to provide easy access to the spark plugs and the valve covers.
System tuned with the heads, cam and intake to provide maximum effect between 5,000 to 7,800 rpm.
Attachments
i meant to say there is a lot more in it
If one pound of boost makes that much of a difference at your the level you are running 8's will be no problem. i am so impressed at the craftmanship of the car. i know you have a lot of time in it and it is nice when it pays off..............................BobEngine management
Electromotive TECII. Presently, Electromotive TEC3r.
Waste spark system.
Fuel methanol.
One 160 lbs/hr electronic injector per intake runner.
One nitrous port injection nozzle per intake runner.
Nitrous system HP level 200HP.
The fuel side of the nitrous system is about 80 lbs/hr, per intake runner, fatter than what is required by the nitrous oxide system. This was done to augment the electronic injectors, because 160 lbs/hr @ 85% duty cycle just wasn't enough. When the nitrous is activated, the electronic injectors are throttled back and used to trim the mixture. The nitrous oxide side of the nitrous system is shut down at 16 psi boost level. At that moment, the fuel side of the nitrous system remains on and the electronic injectors are again throttled back and used to trim the air/fuel mixture. It really isn't as hard as it sounds.
Ignition timing is very close to what is required for gasoline.
Electromotive TECII. Presently, Electromotive TEC3r.
Waste spark system.
Fuel methanol.
One 160 lbs/hr electronic injector per intake runner.
One nitrous port injection nozzle per intake runner.
Nitrous system HP level 200HP.
The fuel side of the nitrous system is about 80 lbs/hr, per intake runner, fatter than what is required by the nitrous oxide system. This was done to augment the electronic injectors, because 160 lbs/hr @ 85% duty cycle just wasn't enough. When the nitrous is activated, the electronic injectors are throttled back and used to trim the mixture. The nitrous oxide side of the nitrous system is shut down at 16 psi boost level. At that moment, the fuel side of the nitrous system remains on and the electronic injectors are again throttled back and used to trim the air/fuel mixture. It really isn't as hard as it sounds.
Ignition timing is very close to what is required for gasoline.
Transmission and torque converter
THM475 transmission. OEM gearset and ratios.
8 pack intermediate, 12 pack direct.
Pump modifications to control pump gearset pocket wear and control torque converter hydraulic feed rate and hence the internal hydraulic pressure inside the torque converter. This eliminates any chance of crankshaft thrust problems.
Mainline pressure 200 psi. Mainline is the working pressure supplied to the clutch packs, not the torque converter.
Stock input shaft and forward clutch drum. This assembly is a PM item changed out annually.
Pressurized lube feed to the extension housing bushing.
Hughes manual reverse pattern valve body w/transbrake.
3.5" diameter mild steel driveshaft with 1350 solid cross u-joints front and rear. Spicer front yoke.
Neal Chance bolt together 10" Pro Mod torque converter.
Mechanical diode.
Torque multiplication around 1.44.
Slip factor 5.8.
Converter capacity 204.
The stall speed with the new engine (lower static compression from 11.27 down to 9.0) is 2750 rpm at 0 boost.
Stall at 3 psi boost is 3250 rpm. Nitrous activation is at 3300 rpm.
It takes a little less than one second to go from 2650 rpm @35% throttle to 3250 rpm @ WOT.
After nitrous activation at 3300 rpm, the engine rpm increases to 3600 rpm and manifold pressure to 16 psi in about .4 seconds.
A typical staging goes like this;
I stage the car at 2650 rpm or so, and WOT on the first amber light. By the time the last amber lights, it's time to release the transbrake and a split second later the nitrous comes in. This strategy causes the driveline backlash to be taken up under a lighter load, before the nitrous hits. Less fatigue on driveline components.
THM475 transmission. OEM gearset and ratios.
8 pack intermediate, 12 pack direct.
Pump modifications to control pump gearset pocket wear and control torque converter hydraulic feed rate and hence the internal hydraulic pressure inside the torque converter. This eliminates any chance of crankshaft thrust problems.
Mainline pressure 200 psi. Mainline is the working pressure supplied to the clutch packs, not the torque converter.
Stock input shaft and forward clutch drum. This assembly is a PM item changed out annually.
Pressurized lube feed to the extension housing bushing.
Hughes manual reverse pattern valve body w/transbrake.
3.5" diameter mild steel driveshaft with 1350 solid cross u-joints front and rear. Spicer front yoke.
Neal Chance bolt together 10" Pro Mod torque converter.
Mechanical diode.
Torque multiplication around 1.44.
Slip factor 5.8.
Converter capacity 204.
The stall speed with the new engine (lower static compression from 11.27 down to 9.0) is 2750 rpm at 0 boost.
Stall at 3 psi boost is 3250 rpm. Nitrous activation is at 3300 rpm.
It takes a little less than one second to go from 2650 rpm @35% throttle to 3250 rpm @ WOT.
After nitrous activation at 3300 rpm, the engine rpm increases to 3600 rpm and manifold pressure to 16 psi in about .4 seconds.
A typical staging goes like this;
I stage the car at 2650 rpm or so, and WOT on the first amber light. By the time the last amber lights, it's time to release the transbrake and a split second later the nitrous comes in. This strategy causes the driveline backlash to be taken up under a lighter load, before the nitrous hits. Less fatigue on driveline components.
Unbelievable craftsmanship Don. I have a feeling you work more on the car than transmissions:tongue: I have a question for you, and if you don't want to answer I completely understand. How much personal time(hrs) and $$ do you think you have in just the drivetrain alone? I know what was involved with my project(only half as nice as yours) and can only imagine what you spent to get where you are....Where is the magazine coverage???
-scott wile
When you have great guys working with you, you need to find something to do with your time. I still get my hands dirty when an interesting job comes around or a part needs to be fabbed up for a job that one of the others is working on. Really, I started on this adventure in 1991 when I bought my first Stage II off-center block from Kenny. Available money always kept things at a snails pace. The first project engine kinda followed what everyone else was doing (except for the methanol :biggrin: ) and when that one blew in 2001, my new vision required me to learn some new skills and aquire some new tools, so that slowed me down some too.
As far as $ involved, in parts alone, throughout the whole project, somewhere over 70,000. That doesn't include the labor for the parts I made and the other assembly labor. I have absolutely no idea how much time I've spent on this car. Some people that know me well would probably say I spend 24/7 on it. I hope it really isn't that much. I've thought about getting ahold of a magazine. When I feel she's ready, I guess.
When I get a chance, I'll post some tuning numbers and interesting characteristics to watch out for when tuning your engine using 100% alcohol.
One scary deal is called 'lean runaway'. It's a really wierd deal. My friend Murl, who had much more tuning experience than me with all types of fuels, including nitro, would just sit there and smile when I first experienced 'lean runaway'. I guess he thought it was cute watching the confused expressions on my face.
One scary deal is called 'lean runaway'. It's a really wierd deal. My friend Murl, who had much more tuning experience than me with all types of fuels, including nitro, would just sit there and smile when I first experienced 'lean runaway'. I guess he thought it was cute watching the confused expressions on my face.
Engine configuration, accessory mounting
This is a front view of the engine on an engine stand, showing the accessory mounting. I'll post a picture of the timing cover alone later. It came out pretty cool.
This is an older picture. There are lightening holes in the trigger wheel now.
This is a front view of the engine on an engine stand, showing the accessory mounting. I'll post a picture of the timing cover alone later. It came out pretty cool.
This is an older picture. There are lightening holes in the trigger wheel now.
Attachments
Had to use stock parts somewhere. It's a fairly rigid part, so it helps keep things out of the belts. I believe the radiator is the other stock part.....all those nice custom parts and technology but you're still using the ugly, stock, oil return line!
- Joined
- Jun 18, 2001
You have to take the converter into consideration. Right now you are at 7.6% efficiency which is pretty good. If you go with smaller gear and taller tire you may kill the efficiency. We went from a 3.70 gear and 28.5 tire to a 3.50 gear and 29.5 tire adn the efficiency went from 6.5% to 18% on the big end. We've since switched to a tighter converter and a VSC to solve that problem and it has worked VERY well.
Have you dynoed that motor at all to see were that cam makes power? A 108 LSA seems tight especially with a cam that size. On an engine dyno a 232/232 cam was starting to fall off after 5900 rpm. THe same cam specs with a 244/244 duration was better but still started to fall off after 6200rpm and killed our TQ numbers all together. We are getting ready to try another round of cam testing but on a chassis dyno this time. I currently have a DLS 236/236 and I'm waiting on a new grind to show up.
Bottom line, figure out what your trap rpm and mph need to be and gear your car accordingly then spend the rest of your life trying to find the right cam and converter for that perfect combo
You have to take the converter into consideration. Right now you are at 7.6% efficiency which is pretty good. If you go with smaller gear and taller tire you may kill the efficiency. We went from a 3.70 gear and 28.5 tire to a 3.50 gear and 29.5 tire adn the efficiency went from 6.5% to 18% on the big end. We've since switched to a tighter converter and a VSC to solve that problem and it has worked VERY well.
Have you dynoed that motor at all to see were that cam makes power? A 108 LSA seems tight especially with a cam that size. On an engine dyno a 232/232 cam was starting to fall off after 5900 rpm. THe same cam specs with a 244/244 duration was better but still started to fall off after 6200rpm and killed our TQ numbers all together. We are getting ready to try another round of cam testing but on a chassis dyno this time. I currently have a DLS 236/236 and I'm waiting on a new grind to show up.
Bottom line, figure out what your trap rpm and mph need to be and gear your car accordingly then spend the rest of your life trying to find the right cam and converter for that perfect combo
The 7.6% efficiency figure you came up with, did you include tire growth? After including tire growth, I calculated it to be in the high 8s. I'm just curious. I want to make sure I'm not missing something in my calcs.
You're correct about the higher gearing or taller tire deal. The sim doesn't like it. It does like 4.33s, but that makes my trap rpm worse. At least, that would be the case for the 1/4 mile anyway. Have to get back to work. We'll talk cams later.
- Joined
- Jun 18, 2001
I checked out the site. The formula is very simplistic. It does not take into consideration tire growth. At 150 mph, the tire growth can be 5-8 percent. A pro stock application can be 10%. A top fuel application, 20%.
If you want to check out some top notch calculators, go to Performance Trends site.
Chris. When you are trying different cams on the dyno, are you using matching exhaust headers with each different cam to take advantage of gas pressure pulse tuning? This is very critical with long duration/high overlap cams. The wrong pulse tuning with a long cam can be killer. The whole gas flow package should be looked at as one system. The exhaust headers that are typically used on the Buick V6 these days is absolutely horrible, from the stand point of pulse tuning. Small cams with little or no overlap are not hurt by bad pulse tuning. The story is vastly different when you start exploring larger cams. If you're trying to match a cam to your intake and exhaust manifolding, then that's one story. If you're looking for more HP, you will find it with larger cams, if you're willing to tune the rest of the engine to match the needs of the cam.You have to take the converter into consideration. Right now you are at 7.6% efficiency which is pretty good. If you go with smaller gear and taller tire you may kill the efficiency. We went from a 3.70 gear and 28.5 tire to a 3.50 gear and 29.5 tire adn the efficiency went from 6.5% to 18% on the big end. We've since switched to a tighter converter and a VSC to solve that problem and it has worked VERY well.
Have you dynoed that motor at all to see were that cam makes power? A 108 LSA seems tight especially with a cam that size. On an engine dyno a 232/232 cam was starting to fall off after 5900 rpm. THe same cam specs with a 244/244 duration was better but still started to fall off after 6200rpm and killed our TQ numbers all together. We are getting ready to try another round of cam testing but on a chassis dyno this time. I currently have a DLS 236/236 and I'm waiting on a new grind to show up.
Bottom line, figure out what your trap rpm and mph need to be and gear your car accordingly then spend the rest of your life trying to find the right cam and converter for that perfect combo
To answer your question, Chris. I have not dyno'd the engine or car. All the performance figures I've come up with have been calculated from 1/8 and 1/4 mile performance, along with matching sims to the performance indicated by the time slips. The estimated peak HP rpm for the cam I'm using is around 6,700 rpm. Even so, the engine's pull does not let up all the way to 8,100 rpm, even though the sim states hp should be dropping off after 7,200 rpm. This is accomplished with a relatively small valve head.
The fact is, this complete engine configuration was first done on an engine analyzing program. Every single specification of this engine was figured out first on a simulation program with all individual systems optimized with the heads limitations at the core.
You are absolutely right about long duration killing low to midrange torque. Hence, the use of torque in a bottle. Once you get the engine up on the cam (and headers) and boost to around 18 psi, the gates of hell open around you.
The fact is, this complete engine configuration was first done on an engine analyzing program. Every single specification of this engine was figured out first on a simulation program with all individual systems optimized with the heads limitations at the core.
You are absolutely right about long duration killing low to midrange torque. Hence, the use of torque in a bottle. Once you get the engine up on the cam (and headers) and boost to around 18 psi, the gates of hell open around you.
