Interesting conversation going on here but if everyone thinks the issue is just with the size of the exhaust valve or high boost pressure acting on the valves then you better do a re-think. Why would you want two superchargers or twin turbos if the heads were a limiting factor or if high boost was keeping the valves open? My 4.6L 2 valve produces over 500 HP at the rear wheels. I use SVO heads that are not ported/polished (review what Steve posted as exhaust flow #'s for these heads). Can this be? Can I get my level of performance with heads that flow less on the exhaust side than the stock Lightning heads. I have a friend that uses the same basic combination and produces over 560 HP at the rear wheels. I run with 14 lbs. of boost and my friend has close to 20 lbs. of boost. Here is a clue I tried to use the 41 lbs. Lightning injectors and they would not support my fuel demands. I use 93 lbs. injectors and my car is as tame as can be. One more clue I use the 1999 Mustang GT cam and it is the same basic one as the Lightning. I think that you can get my drift.
P.S. Chet, I am sure your HP issues will be resolved even before you go to the better heads and new motor. I think you stated where your problem was when you said " the motor is not turning above 4800 RPM's" Just ask yourself why or I will tell you when you call.
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BABolt
SVT#290




[This message has been edited by BABolt (edited 12-23-2000).]

 

Hi BaBolt
I thought about what you just said,and I have a question. First of all, 8 41 lb injectors (at a BSFC of .5)should cover at least 500 Hp maybe more. I know guys in the buick world that cover more than 500 Hp with only 6 42lb injectors. So my question is, is it the fuel injectors? or is it something else? Fuel pumps maybe? Maybe he just needs an adjustable fuel pressure regulator. Does the lightning have a boost referenced fuel pressure regulator? I've never bothered to look.
Dale

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Black 00'
13.21 @ 105.24 so far
full weight, stock tires

 

Great reply! WE have TWO fUEL pumps, a super cool adjusting fuel regulator and a mechanical gauge installed that surprised us all and never fell below 60psig, Steady as a rock? We have played the fuel game and we have gone no where, Thanks for the suggestions!!!!

 

Hello,
My point is not that two blowers or twin turbos is a bad idea (I think that both ideas are great and have merit and I also know why Chet chose his setup, it keeps the basic Lightning concept intact). Is there an issue with the cylinder heads when you are trying to gain high flow levels. Yes, but I think that you can get to at least 500 HP at the rear wheels. I also don't think that it is "just" an exhaust valve issue. If you want to change the valve spring go right ahead and when you find the right ones please tell all of us about it. Maybe "Fox Lake" has some information they are now doing cylinder heads for "mod motors" Please take a close look at these heads or cut a cross section through one and you will see for yourself. Also if you want to replace them your choice is limited. Want to run the 4 valve head,you can kiss your supercharger goodbye at least with the current intake manifold design. What is left, port and polish the Lightning head or the SVO head. Check with "Fox Lake" on the two Ford heads they are known for high quality work and you can check with Edelbrock too they design, cast and machine and their quality speaks for itself. What I have been geting at is that I "think" (that is the operant word and I can be wrong) that the source of Chet's lower then expected HP readings is on the air/fuel delievery side. As he stated he cannot rev over 4800 RPM. If you look at Lightning dyno plots you will see that peak horsepower is acheived at about 5000 to 5200 RPM's. That is why most Lightning drag racers try to run through the traps at just a little over 5200 RPM's at least the smart ones do. Additionally, look at Chet's engine setup there is parasitic drag to contend with, two superchargers and was the A/C running and did he get the expected 30 degree drop in intercooler temperature. Here is another idea for you. When Nascar wants to limit HP they use a restriction plate, the air/ fuel ratio is still correct you just can't get enough of it. Please do not read any of this the wrong way. I have just expressed some of my thoughts, can I be wrong of course I can. Good analysis has to start with a hypothesis and then testing. I appluad Chet for what he is doing as many of us can only wish to get to this level.

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BABolt
SVT#290

 

Never taken the wrong way Bolt I may not post much here but Ive been here for a long time..long enough to enjoy getting into discussions with the best of you ! I applaud him as well. I too believe 500 hp is attainable ...and on that note i wish all of you a merry christmas and great new year!
peace,
seb@NLR

 

n20boy
I agree with you about the turbochargers that is a kill way to make BIG power,but I also agree with BaBolt on maintaining the Lightning concept. I have visions of a streetable Lightning with an Enderle bug catcher sticken out of the hood.(are you listening HighRisk) LOL. I also agree with BaBolts analogy of the NASCAR restrictor plates. I think 38TopGuns problem is air/fuel related or lack there of,but that can come in almost any form. I've looked at the port flow numbers that SilverBullet provided and If the numbers were at a pressure drop of 28"H20 then even the stock heads should get you over 500 HP.
So here is another restriction for you. How about the manifold adapter? It hugs the top of the supercharger real tight then rises up and makes a total of a 180deg turn before it drops the air onto the rotors. Not only that but the back edge of the manifold is clipped at about a 45deg angle for firewall clearance. Might be worth a look. I'm not talking about a port and polish job on this piece, it will take a total rebuild (a cut and fab project) to get more air around that corner.
Happy Holidays
Dale

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Black 00'
13.21 @ 105.24 so far
full weight, stock tires

 

Just a few photos, I've posted these before but you can see that I have cut open and revised many of the Lightning engine components.












Dyno plot and you can see the power peak.

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BABolt
SVT#290




[This message has been edited by BABolt (edited 12-23-2000).]

 

I agree also..wasnt trying to say thats not the case.. Man Bolt looks like my kind of christmas hehehe.

 

Hi BaBolt
I have kept an eye on what you are doin,I've seen these pictures over at Zing. And I want to say that you do very nice work! I've been wanting to tell you that for some time but I just recently came out of the closet and started posting. Some peaple on this board get kinda Pi$$y or jealous when they see pictures like that. Hell I can't get enough of it, I wish you and 38Topgun would post more often. It keeps life around here interesting.
Thanks
Dale

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Black 00'
13.21 @ 105.24 so far
full weight, stock tires

 

Nice looking stuff on the inlet side!! MY comment on the 4800 rpm was only just that the motor is dynoing to 5400 rpm but not making much power. I would prefer not to spin the motor to hard. I am investigating both sides of the motor for losses and would agree that the inlet could be contributing also. I won't comment until I measure things. Babolt definitely has spent way more time on this side then I have with the stock parts. Time will tell,when in doubt more boost!!!!!!

 

Finally a great discussion for Christmas. First off, I’m no Ford Engineer. With that said I believe the basic formula for horsepower is:

ENGINE HP = [Injector flow rate (@ 43.5psi)]*[# Cylinders]*[Injector Duty Cycle]/ BSFC

Assuming a 41lb/hr injector flow rate, 8 cylinders, an injector duty cycle of 80%, and a BSFC of 50%, one calculates only 524 HP. This is NET ENGINE HP potential, not RWHP. Now Chet has stated that he has bumped his fuel pressure up to 60+psig. The increased fuel pressure effectively increases the flow rate of the injectors by approximately the square root of the fuel pressure ratios. So we would then have an effective injector flow rate of 41*[(60/43.5)^.5] = 48 lb/hr. Therefore Chet’s motor has the potential of making 48*8*.8/.5 = 614 netHP. The problem as I see it is Chet has TWO superchargers to turn. According to Eatons website, the M112 requires almost 45HP to make 8psi (a pressure ratio of 1.54) at 4800 engine RPM. I don’t know what the Paxton consumes. And I don't know what Chet's current configuration is for PR's on each blower. But let’s conservatively assume a total of 75HP to spin both superchargers, and assuming Factory Techs previously posted 11% for drive train loses, we end up with 479 RWHP. This seems pretty close to the 460HP wall Chet saw. My numbers probably have some holes in them (shoot away). Looks like more fuel will be required to get over the hump. For now I guess I stand corrected on the exhaust valve side of things (although I do stand by my previous atatement that the valve seat pressure/spring has nothing to do with Chet’s HP wall).

 

I love you engineers and all that calculating stuff!! Just got off the phone with Mike and tossed around some ideas. Fuel seems to be major offender at this point. We are going to pursue this asap. Also, we are building a blower dyno for Paxton as we speak with all kinds of trick data acquisition stuff. Seat of the pants belief is that the Paxton in all of it's glory is slurrping down 75 ponies to turn the thing? We shall see. Thanks for the help and the xxxl's are on the way!!!!!!!!!! Do me a favor and walk by Desisto with the shirt on! Looks like he is going to be awfully busy in the near future.

 

Chet,
When we spoke you stated that the fuel was still on the rich side. I went back and looked at the photo of your setup and just wondered if air flow is not the issue. If you are running a K&N 7 inch filter under that aluminum cover you would be killing your air flow. The K&N has a chrome cover over the end and with the aluminum cover over the filter element you would be asking the air flow to do some pretty strange tricks. Even with a Big Mouth filter you will not pull enough air through the fender opening to give you the flow to support your intended horsepower levels. Ford did change the size of the fender opening for 2001. Pull the cover and go for a ride. If it is a K&N filter replace it with a Big Mouth. The Levi Dyno will give you a quick indication. Oh yea, let us know.

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BABolt
SVT#290




[This message has been edited by BABolt (edited 12-23-2000).]

 

Just had to add a little story. I had mentioned this once before. When I did my initial dyno testing over a year and a half ago I added the Pro-M air meter with the K&N filter. In my haste to continue testing I did no completely remove the plastic wrap from the K&N filter. I found out real fast what an obstruction can do to air flow. I saved that dyno info too. Thank you for the chance to converse with all of you and Merry Christmas too.

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BABolt
SVT#290

 

The novi-2000 is capable of 27psi and 1000hp, by itself, so in the words of that plant in "The Little Shop of Horrors" FEED ME