I'm not sure what car you're driving, but I cruise at 3,200 RPM in 5th gear (4.56s ~75MPH) and can not achieve greater than 20MPG highway (23MPG city). When cruising with my 3.27s, I could get 25MPG all day long. My 98 would get over 28MPG highway.Kcobra99 said:
Driving at high RPMs - Question
- Thread starter paulk
- Start date
paulk said:
So do I, but be careful with modding and showing signs that you've been racing. Guess if you stay on the highway you'll be OK.
lemosley01 said:
I believe the reason that Ford went to DOHC and aluminum is weight-savings (ironically enough) and fuel economy. I'm also sure it also had alot to do with remaining credible as a manufacturer of up-to-date, competitive, performance cars (both street and track). Just look at some of the gas economy figures reported with Mod 4.6 motors...pretty damn good considering the HP they put out. This is definitely an "advance" over the older pushrod motors. Add in computer control and EFI and you can dial these motors in very precisely. Ford/SVT should definitely be lauded for this. One reason I bought my 2001 is because I could rationalize the decent gas mileage...really. Weight-wise, considering the extra weight of the DOHC setup, an aluminum block would be required. Now the 03/04 Fe block with SC AND DOHC is incredibly heavy....Ford had to go this way because they could not build a REALLY dependable Al block. Now we understand why they went the Incredible HP Route with the GT500...they have to compensate for the EXTRA weight!!! Not a problem if you like to go in a straight line, but weight, as you will read in the GT500 forum is a big concern. GT500 is still an awesome accomplishment.
quadcammer...we alluded to the "history" of Modular development earlier...you said 12 years, I said over 20....If you read about the 351 Cleveland (a 70's motor as in my 1970 Cyclone GT) in the corner-carvers.com forum you will hear how that motor ALSO had oiling problems on the track. Hence, Ford should have learned from that experience and applied it moving forward. And that problem has nothing to do with the DOHC setup, it's basic roadrace engine tech.
Here's my recommended solution to Ford/SVT....if and when you start developing the next Al DOHC N/A block put the damn thing in a Mustang/Cobra and run it around a racetrack - under G's - NON-STOP for a few WEEKS. Signup a bunch of Cobra/Mustang enthusiasts to do the driving....we'll be jumping over each other to be in on this test....won't cost you a dime in professional drivers. Now that's the kind of engine test Cobra OT/Roadracers would really benefit from. A 600-hour BENCH test is useless for a roadrace engine. You need G's!!!
serp, the ls1/ls6 is lighter than the 4v by quite a bit. its also a good bit smaller, but moving on.
I believe ford went to the mod motor for NVH and emissions reasons. they can leave them(the windsor motors) in suv's/vans and what not, but I don't think they could get them to pass for cars. I do not know this as fact, im speculating.
the wap/teksid difference is nonexistant when talking about 320rwhp vehicles. the blocks do not have durability issues until you start pushing serious power.
I believe ford went to the mod motor for NVH and emissions reasons. they can leave them(the windsor motors) in suv's/vans and what not, but I don't think they could get them to pass for cars. I do not know this as fact, im speculating.
the wap/teksid difference is nonexistant when talking about 320rwhp vehicles. the blocks do not have durability issues until you start pushing serious power.
Wow, every one on here must be completely oblivious because, the DOHC is far better then the old pushrods. Just look at how easy it is to add big power with a blower/turbo/nitrous! these cars flow so well and just dont make the kind of power n/a like the ls1 only because of the smaller displacement. Look at the cobra r with its 5.4L and it made 385.
I just am shocked some times at the replies I read on here.
Also, even though the 03/04 engine weighs so much, those cars handle pretty dam well...I mean if you want all out handling, go out and buy an Elise.
I just am shocked some times at the replies I read on here.
Also, even though the 03/04 engine weighs so much, those cars handle pretty dam well...I mean if you want all out handling, go out and buy an Elise.
ROTFL. the dohc is not far better. Its got twice as many valves, 4 times as many cams, and 2 long ass chains driving the valvetrain. Thats a lot more complexity. In stock form the headflow isn't terribly impressive either. 245 I @.5 valve lift/ 175 E @.5 isn't great. Compared to a stocker e7 sure its impressive, but considering heads like the afr 185s, 205s, and 225s, its nothing that can't be reproduced on an ohv motor. look at the ls7, 360cfm Intake on an OHV motor. The cobra R was pretty much a race motor with custom parts such as that intake and the heads (which are now more common).chuckstang said:
the ohv windsor motors are cheaper, lighter, smaller, and less complex.
take a 351w block, bore it out a bit, add some stroke and you are looking at 392 cubes. add some 225 heads, a decent rotating assembly and you are making some serious power. add some boost/nitrous and the power can be insane.
CobraRed01 said:
Yep, I'm familiar with the posts on CC about the DOHC engine woes that several of the guys have had. I subscribe to the theory that it depends on who screwed it together, not that there is anthing fundamentally wrong with it.
Yes, mine is an early (Teksid) block - but I don't know that it is stronger - read about the blocks here: http://www.mustangweekly.com/2003/January/Block/block-1.asp
I'm only making 280rwhp - I think that helps keep it in one piece
Hey Daron,oz98snake said:I'm only making 280rwhp - I think that helps keep it in one piece
Didn't know you haunted this place too
wat about ppl with forged internals?
badboycali_559 said:
That's a good question, but the same should still hold true, although an engine with forged internals may or may not hold up better.
Maybe someone has some insight into WHAT exactly would wear out. Other than a rod or piston failure outright, what else are we wearing out 'faster' when driving at high RPMs? Rings, piston bores? More fatique in the connecting rods and pins? How about journals and bearings, although they *should* be riding on the oil cushion and not making contact. Once the engine is started and you have oil pressure, there is really very little metal-to-metal contact.
I can see the accessories wearing out faster since they are turning at a higher rate of speed, but I've never really THOUGHT about what in the engine would wear out faster.
oz98snake said:Yep, I'm familiar with the posts on CC about the DOHC engine woes that several of the guys have had. I subscribe to the theory that it depends on who screwed it together, not that there is anthing fundamentally wrong with it.
Yes, mine is an early (Teksid) block - but I don't know that it is stronger - read about the blocks here: http://www.mustangweekly.com/2003/January/Block/block-1.asp
I'm only making 280rwhp - I think that helps keep it in one piece
That's an excellent link...thanks. I hear the Teksid block is stronger and better for really high HP applications. I was wondering if "oil starvation under G's" was also an issue with these blocks. If not, the WAP block was a step backward in that area as well.
the internals on these 320rwhp cars is not the problem. the two main problems with these cars is cooling and oiling. the drivers side head has the cooling problem and although it will run cool on the street, they can get mighty hot on the track. this can lead to less power and inevitable damage.
the oiling system is not horrible, but the pump design is a little questionable. It rides on the flats of the crank and the pump gears can rock around a little bit causing wear (especially with billet gears). with the stock pan, running 6 quarts while road racing is another reason why some motors spin bearings (and possibly then throw rods). the oil pump pick up can be uncovered pretty easily in high G situations, so either run more oil or get a bigger pan.
its not the blocks fault, its the pans fault. it doesn't have any baffles and like any other wet sump, the oil will just run away unless you have enough in there.
the oiling system is not horrible, but the pump design is a little questionable. It rides on the flats of the crank and the pump gears can rock around a little bit causing wear (especially with billet gears). with the stock pan, running 6 quarts while road racing is another reason why some motors spin bearings (and possibly then throw rods). the oil pump pick up can be uncovered pretty easily in high G situations, so either run more oil or get a bigger pan.
its not the blocks fault, its the pans fault. it doesn't have any baffles and like any other wet sump, the oil will just run away unless you have enough in there.
Oli as the voice of reason. What would they say at BON?quadcammer said:
All the problems with the stock 4v can be solved with the proper application of parts and money. I think the one important thing to realize is that these blocks were still designed for street use. Why do you think Ford will void our warranties if they are raced? The cars are not designed to be raced (frequently or for long durations). Sure the car can handle the occasional sprint up to high speeds but it's still a $30,000 vehicle. There are lots of constraints that need to be placed on the build to keep the price reasonable. A wet sump, non-baffled pan is one of those solutions. Why does the GT[40] have a dry sump pump? It's designed for race conditions.
You just have to learn what are the pitfalls of a motor, and, unfortunately, it's going to take some people losing theirs for the general population to realize what changes need to be made.
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yeah, the pan is fine for a stock vehicle (especially with an extra .5 to 1 quart more oil), but its just not gonna cut it for a heavily OT'ed cobra.
I would class my Cobra as a "heavily OT'ed Cobra" it's on the track 20+ days a year! And driven damn hard too. Now until recently, I always used MAx performance street tires like the Kumho MX - and one of the reason I did that is because as soon as I up the Gs by running on race tires, I know I am going to have oiling issues.
I have been running on R compounds this year, and have been closely monitoring the gauges for any sign of pressure dips when cornering - so far so good - but I do run an extra 3/4 quart of oil at the track. Changing the pan is a major pain in the butt, and for about the same money, you can install an accumulator, so I think this is the way I will go for added insurance against oil starvation.
I have been running on R compounds this year, and have been closely monitoring the gauges for any sign of pressure dips when cornering - so far so good - but I do run an extra 3/4 quart of oil at the track. Changing the pan is a major pain in the butt, and for about the same money, you can install an accumulator, so I think this is the way I will go for added insurance against oil starvation.
Sounds like an accurate oil pressure gauge, a high capacity,baffled oil pan and an accumulator would be a major step toward provding some protection under G's. Any recommendations on best parts to use? Any "streetability issues" doing this upgrade?
Deal is... I only see myself doing a few OT track events a year....2 or 3 max. But that sounds like that's just enough to lunch a motor, based on the corner-carvers thread. I was planning on keeping the car forever, so the oiling upgrade investment might be worth it. Of course, I should figure on saving up for new motor, cause it sounds like I might need it. Too bad SVT doesn't have the same bulletproof, out-of-the-box motor solution for the "high G-guys" as they do for the "Low ET-guys" (03/04/GT500). Improving the oil pan and adding an accumulator is something I would expect to have to do anyway...but the overheating problem and some oil return problems inherent in the basic engine takes significant time and "green"
to fix. We spends our money and we takes our chances.
Deal is... I only see myself doing a few OT track events a year....2 or 3 max. But that sounds like that's just enough to lunch a motor, based on the corner-carvers thread. I was planning on keeping the car forever, so the oiling upgrade investment might be worth it. Of course, I should figure on saving up for new motor, cause it sounds like I might need it. Too bad SVT doesn't have the same bulletproof, out-of-the-box motor solution for the "high G-guys" as they do for the "Low ET-guys" (03/04/GT500). Improving the oil pan and adding an accumulator is something I would expect to have to do anyway...but the overheating problem and some oil return problems inherent in the basic engine takes significant time and "green"
to fix. We spends our money and we takes our chances.
paulk said:
:lol: hahahaha.
Ok... cruise in 5th, and then DOWNSHIFT to 3rd when you want to blast to the redline, it isn't that difficult Unless you suck at driving a stick of course.
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CobraRed01 said:
If you are only doing 2 or 3 OTs a year, then you should be just fine sticking in an extra 3/4 of oil for each event - and making sure it's freshly changed before each track weekend as well - especially if you are running on street rubber. Of course, good gauges are always added insurance.
An oil pan like the Canton is a bitch to install - unless you are a doing a K member upgrade, then it's easy and worth the expense while you have access. Canton also makes the Accusump Accumulator - both items will set you back about $350 each, and are quite streetable.
For cooling, I run 80/20 water/antifeeze plus water wetter in the stock rad with a 180deg high flow stat - and with no underdrive pulleys. I do plan to upgrade the water pump to help with the TX summer heat - probably use the V10 pump like the old Bondurant school Cobras used to - then I should be able to run the underdrive pulleys again. The "cooling mod" that adds an outlet to the back of the driver side cyl head is definately worth doing to any mod motor, but especially a car that sees the track. This is not a difficult mod to do - whether you use DIY parts, or one of the "kits" that are being offered - but it does require that the tranny be pulled for access to the rear of the cylinder heads.
Another good mod for keeping the temps under control are a set of headers - getting those lumps of heat soaking cast iron off of the heads makes a big difference - and of course headers have other more obvious benefits as well
what is water wetter? I have heard of it before but have no idea what it is or what it does???? thx
oz98snake...thanks for the info...again!! Real useful recommendations for anybody considering OTing their Cobra. Changing to headers to reduce head temperatures is something I would not have considered...probably a real "head saver" for the Cobra motor. Do you have a link to a how-to-do resource for the "cooling mod" you recommended? How many times do you track your car a season?
CobraRed01 said:
I didn't consider it either until it was pointed it out to me - and then of course it becomes obvious and I wonder why I didn't think of it myself.
Hmm, I have info, but not one definative link comes to mind - there is plenty about it on the forums and in various archives if you hunt around a little. Maybe this one will help - it is for a "kit" for the 03/04 Cobra - but if you wanted to do it yourself, the picture paints 1000 words
http://www.modularfords.com/forums/showthread.php?t=24580Users who are viewing this thread
