Re: Race Engine reality, what works
[Re: Cab_Burge]
#2734320
01/18/20 09:19 PM
01/18/20 09:19 PM
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Joined: Mar 2006
Posts: 9,985 MI, usa
dvw
OP
master
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OP
master
Joined: Mar 2006
Posts: 9,985
MI, usa
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What I know works: less weight, more compression, make the engine as big as you can. So I started out with making my car as light as I could while maintaining the look I wanted. 3350 with me ready to race. Then it got a 15-1 572. The 5th full pass the car ran 9.3x. Since that time (630 passes) it has had engine maintenance parts. But still has the same heads, compression, cam,& rockers, headers, carbs and intake. Learned what lives and what doesn't. Pac valve springs, Isky bushed lifters, Landrum rear coil springs, Molnar crank, US gear pro gear have fixed any problems that have occured. Maintenance is very low. Same type tires (M/T 10.5Wx31) and overall weight. Swapped rear gear from 4.10 to 4.30 no real change. Aluminum high drum replaced a billet steel unit along with lightening the sun shell. This was worth nearly a 7lb reduction. It was also worth close to .10 in the 1/8th. Various converters picked up .20 putting the car in the 9.0x range. Shocks and springs have helped consistency but really haven't made the personal best any better (1.25, 5.72@121, 9.00@150). Though they sure have helped to put the car in the winners circle. In ways I'm a lazy tuner. Never really chased jetting, lash, timing. We've moved it a little with no real improvement. However nearly every trip to the track for us is a race. Our testing is usally limited to put the car on index or adjust for poor track conditions. We are focused on that. Cant win with a car that won't repeat. Doug
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Re: Race Engine reality, what works
[Re: TRENDZ]
#2734327
01/18/20 09:40 PM
01/18/20 09:40 PM
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Joined: Nov 2015
Posts: 898 Missouri
jwb123
super stock
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super stock
Joined: Nov 2015
Posts: 898
Missouri
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This most likely falls outside of the original topic, but there is no single more important part to having a fast car, than the torque converter. I will totally agree with the converter. couple times I did things that I knew should have picked up the car, but it was like it had a governor on it,. changed the converter and boom several tenths improvement. And I will also say that while I always give all the info asked to the converter companies, I never get the same recommendations from different companies. If the science was good I should get the same basic setup recommendations from every company, but every company gives me a different take on what the car needs. So in my experience you simply have to buy several and sell the ones that don't work out. For example I have asked for advice on camshafts from several companies and the grinds are usually very similar, so I trust those recommendations and just go with the best service. But to answer the post, if you want to see big changes better cylinder heads and more cubic inches, most other things are usually just small increases in performance. And in my experience many times the small things you change may not show quicker ET slips, but I see improvements in consistency, which tells me there was an issue that needed to be fixed.
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Re: Race Engine reality, what works
[Re: Harry's Taxi 2]
#2734339
01/18/20 10:54 PM
01/18/20 10:54 PM
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Joined: Jan 2003
Posts: 5,487 SoCal
Brian Hafliger
master
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master
Joined: Jan 2003
Posts: 5,487
SoCal
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This most likely falls outside of the original topic, but there is no single more important part to having a fast car, than the torque converter. I strongly second this one. I second second this!
Brian Hafliger
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Re: Race Engine reality, what works
[Re: Brian Hafliger]
#2734340
01/18/20 11:01 PM
01/18/20 11:01 PM
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Joined: Jan 2003
Posts: 5,487 SoCal
Brian Hafliger
master
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master
Joined: Jan 2003
Posts: 5,487
SoCal
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I sealed my 6PK scoop to my carb... worth a tenth and 1.5mph. Removed it and jetted down, lost everywhere...jetted back up and gained some, sealed and gained all back. Jetted up from there with it sealed and lost. Working on the car, specifically the front and rear suspension, and launch were the biggest gains.
Brian Hafliger
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Re: Race Engine reality, what works
[Re: Brian Hafliger]
#2734345
01/18/20 11:36 PM
01/18/20 11:36 PM
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Joined: Mar 2003
Posts: 2,541 PA
moparacer
master
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master
Joined: Mar 2003
Posts: 2,541
PA
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I sealed my 6PK scoop to my carb... worth a tenth and 1.5mph. Removed it and jetted down, lost everywhere...jetted back up and gained some, sealed and gained all back. Jetted up from there with it sealed and lost. Working on the car, specifically the front and rear suspension, and launch were the biggest gains. Found the same exact thing with my air pans. Guaranteed 1-1.5 on both cars I tested them on that have 6 pack scoops. The hemi scoops would probably pick up 2 tenths lol. Never picked up so much for so cheap.
67 Barracuda street/bracket car 11.27-119 68 Dart 502 BB 8.70s-152 414 cid SB Dragster 7.65-174
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Re: Race Engine reality, what works
[Re: dart games]
#2734358
01/19/20 02:17 AM
01/19/20 02:17 AM
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Joined: May 2019
Posts: 722 Lake Villa Il
INTMD8
super stock
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super stock
Joined: May 2019
Posts: 722
Lake Villa Il
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just throw it together like i do,only people that make over 6 digits can aford dynos and be so anal about everything,im a average working man,i cant spend all that big money You may have had good results without, and I suspect you have based on your response but wouldn't say dyno time is only for rich people. Isn't that expensive to baseline your combo and do testing from that point on.
69 Charger. 438ci Gen2 hemi. Flex fuel. Holley HP efi. 650rwhp @7250 510rwtq @5700
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Re: Race Engine reality, what works
[Re: dart games]
#2734359
01/19/20 03:15 AM
01/19/20 03:15 AM
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Joined: Aug 2003
Posts: 43,748 Bend,OR USA
Cab_Burge
I Win
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I Win
Joined: Aug 2003
Posts: 43,748
Bend,OR USA
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Isn't the track the best dyno? It took me awhile to figure out I could not make drag race motors get the best tune on a engine dyno sitting still inside a dyno room
Last edited by Cab_Burge; 01/19/20 03:51 PM.
Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)
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Re: Race Engine reality, what works
[Re: Cab_Burge]
#2734368
01/19/20 08:34 AM
01/19/20 08:34 AM
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Joined: Jan 2003
Posts: 2,987 A shed in England
Tig
master
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master
Joined: Jan 2003
Posts: 2,987
A shed in England
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Cam tming. We experimented with a symetrical pattern comp cam around .740 Lift with 1.6 arms. We retarded it 4 degrees and picked a solid 1 1/2 tenths no other changes. Easy enough to do with a Jesel belt drive. FWIW the Indy CM3 (Asymetrical) in there now is best straight up. Don't ask me how I know
'74 Challenger..9.46 @ 145.9 1/4, 6.001 @ 118 1/8 so far. 4023lb !!! # N/A, Marsh performance 655ci, Indy Maxx, T/R, Indy 600-13 X's, Street legal, pump gas, full interior, Cal-Tracs, mufflers, 3:73's and real 10.5 radials. 9.51 @ 142.4 1/4, 6.003 @ 114 1/8 with our old mule KB, 572-13, 580 wedge. RHD '68 Barracuda Fastback 323ci street/strip. Best ET 13.88 @ 99.03
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Re: Race Engine reality, what works
[Re: sasquatch]
#2734370
01/19/20 08:50 AM
01/19/20 08:50 AM
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Joined: Apr 2003
Posts: 1,633 anywhere@ anytime
actionange
top fuel
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top fuel
Joined: Apr 2003
Posts: 1,633
anywhere@ anytime
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Best bang for the buck is Take Weight out of the car, followed by take more weight out of the car, and finally remove weight from the car...... I agree overall light is right, but placing weight in the correct areas will be a benefit. I got a few of those weight tubes added lead shot and scaled the car. Got the car to 49% front 51% rear. More consistent 60 foots and a tenth better et.
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Re: Race Engine reality, what works
[Re: Tig]
#2734372
01/19/20 09:01 AM
01/19/20 09:01 AM
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Joined: Jan 2003
Posts: 8,082 Tulsa OK
Bad340fish
master
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master
Joined: Jan 2003
Posts: 8,082
Tulsa OK
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I agree with the converter comment very much. Also the 727-904 swap is worth ET every time.
If the converter is correct it almost washes out rear gear choice. I went from 3.91 to 4.56 when I broke my 3.91s. The time slip didn't change hardly at all, it was spinning lots more RPM in the traps but that's it. I have seen other people with a good converter do the same type changes and net nothing ET wise. But a car without "enough" or "the right" converter will usually move a fair amount of ET with gear changes.
68 Barracuda Formula S 340
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Re: Race Engine reality, what works
[Re: Cab_Burge]
#2734377
01/19/20 09:38 AM
01/19/20 09:38 AM
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Joined: Oct 2015
Posts: 570 UK
rb446
mopar
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mopar
Joined: Oct 2015
Posts: 570
UK
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What worked best for me back in 1991, my '69 Cuda 3300lbs with home built 446ci motor, 6pk bottom end, Team G, 850DP, 9.8:1, 4800 stall, stock 906's, ran a best of 11.2@118+. Did nothing else but bolt on some 2.14/1.81 906's mildly ported to around 260cfm with HS r/rockers and went 10.7@125 first pass NA. Was running the old MCandless .650"/290@.050 sft cam, and they say it needed 12.5:1 to work, how much faster would it have gone@12.5:1, not that much more I doubt, perhaps a 1/10th?...and there was quite a lot wrong with the car, too loose front end, would top out and not enough air in the 32's to name but 2, would've been a 10.5 car with those sorted.
Last edited by rb446; 01/19/20 09:45 AM.
1969 'Cuda 446ci, best 9.96@133.9 in 1990 1971 340 'Cuda, best 11.01@122.8 in 1987
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Re: Race Engine reality, what works
[Re: INTMD8]
#2734381
01/19/20 10:02 AM
01/19/20 10:02 AM
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Joined: Jan 2003
Posts: 15,439 Val-haul-ass... eventually
BradH
Taking time off to work on my car
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Taking time off to work on my car
Joined: Jan 2003
Posts: 15,439
Val-haul-ass... eventually
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just throw it together like i do,only people that make over 6 digits can aford dynos and be so anal about everything,im a average working man,i cant spend all that big money You may have had good results without, and I suspect you have based on your response but wouldn't say dyno time is only for rich people. Isn't that expensive to baseline your combo and do testing from that point on. I learned things on the dyno that wouldn't have been nearly as obvious if all I was going by was an ET slip, a really good example being valve train instability issues. I learned things on the track that the dyno wouldn't reveal, in one example being two carbs that dynoed virtually identical, but the one that had better shift recovery on the track being worth .1+ MPH and .1+ quicker.
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Re: Race Engine reality, what works
[Re: dvw]
#2734385
01/19/20 10:23 AM
01/19/20 10:23 AM
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Joined: Jan 2003
Posts: 15,439 Val-haul-ass... eventually
BradH
Taking time off to work on my car
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Taking time off to work on my car
Joined: Jan 2003
Posts: 15,439
Val-haul-ass... eventually
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The OP mentioned straightening the lifter bores... Assuming he means bushing them along with blueprinting their locations, I understand the oil control benefits. But is there a measurable performance improvement?"
EDIT: This is of interest to me because my current block has had the lifter bores corrected bushed, but it's "tired" and the cylinders couldn't take anything more than a re-hone during the last rebuild. I've got a freshly machined block to replace it, but the one job the shop that did the work wasn't equipped to do was the lifter bores. Not sure if I should plan to haul it somewhere else to get that done, or build it as is.
Last edited by BradH; 01/19/20 12:03 PM.
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Re: Race Engine reality, what works
[Re: rb446]
#2734391
01/19/20 10:35 AM
01/19/20 10:35 AM
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Joined: Apr 2005
Posts: 2,128 Salt Lake City
camastomcat
top fuel
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top fuel
Joined: Apr 2005
Posts: 2,128
Salt Lake City
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Well, straight push rod angles, 55mm cams, vacuum pumps, dry sump systems, rocker arm geometry, heavy vs lightweight crankshafts, steel vs aluminum rods, ring packs, ect. all effect longevity IMO. If you want to make more power, add CI, heads, camshaft, compression, and fuel system that works with the CI you choose. Then match the converter to that combo. Weight of the car is always a factor as the old saying goes, "less is more". That said, lightweight crankshafts only RPM faster. They don't really make more power unless you're a comp eliminator guy and use 7" converters and even then the improvement is minimal. A center counter weighted crankshaft weight a lot more than a non center counter weight weighted crankshaft, but it is much less prone to cause main cap chatter. Look at the stock/super stock/comp eliminator guys. They get the most out of their parts, and they are pros at picking the right converter for their combo. That is the key as mentioned early in this thread. JMO By the way OP, this is the best post I've seen hear in a long time!
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Re: Race Engine reality, what works
[Re: camastomcat]
#2734415
01/19/20 11:48 AM
01/19/20 11:48 AM
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Joined: Jan 2003
Posts: 12,815 Benton, IL.
DaveRS23
Master of nothing...
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Master of nothing...
Joined: Jan 2003
Posts: 12,815
Benton, IL.
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they are pros at picking the right converter for their combo. That is the key as mentioned early in this thread. JMO By the way OP, this is the best post I've seen hear in a long time! Yes and yes.
Master, again and still
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