http://www1.ls1tech.com/forums/showthread.php?t=553334

With only a 220/224 baby cam!!

Check out link above....

Owner doesn't post on Tech so I thought I would share this rather unorthodox combination that really worked out extremely well.

Customers goal was to make as much power and torque from idle to 5000 RPM's, with upper RPM horsepower a very secondary concern. This was an exercise in building the ultimate SOTP pump gas 402 essentially. Of course everyone likes to see a decent power figure so we opted to port a FAST 78 intake to keep costs down (he already had a ported factory TB) and also I recommended opening up the combustion chambers of the 205's to better take advantage of the larger 4" bore whiched helped increase the low and midlift airflow for even better breathing (still retaining the small ports for high velocity enhancing low RPM and part throttle TQ). Note the gains in low and midlift flow also helped the engine "hang on" long after the smaller cam with this displacement should have signed off. It practically carries peak power for 1000 RPM and is still making a decent number as late as 6600! Honestly, the numbers came in exactly where I hoped, but the way the top end charge hung on surpassed my expectations. Plus, I really wasnt focusing at all on optimizing this combo past 5500....although some of the decisions I made aided both peak and area under the curve power which this combo was really being aimed at. The owner rarely races and was looking for a daily driver stump puller that would also hold its own if an occasional opportunity presented itself.

The guys at EPP did an excellent job with the install and tune, not to mention took the time to document and take pictures of the whole process. I highly encourage you guys to take a look at all the pics and documentation of this build which you would be directed to in the link above.

Toward the bottom of all the EPP pics and information is the dyno sheet and then a comparison to his 346 which ran the exact same 205 heads (sans the chamber work) and of course a small cam somewhere in the mid teens @ .050. The overlay of the two graghs is the very meaning of "area under the curve" and simply has to be seen. Also, from what I hear from the guys at EPP who drove this car and the owner himself, the part throttle surge is incredible. Tim (the owner) tells me you can come around a slow corner in third at low RPM and give it a little gas and the car just starts to haul booty.

I would have loved to seen this car on a typical DynoJet....my guess is 500 ft/lbs/ 480 HP....not to mention these numbers are thru a power robbing 4.10 Moser 12 bolt.

Bob....anyway of posting the dyno curve and the overlay in this thread directly? I'm sure alot of people would like to see it that might be too lazy to start clicking on the links etc.

Hope you guys enjoy the info....Im sure this exercise gives more than a few of us some things to think about. You dont need a big cam to make big power....just a well thought out combination with the right parts and taking the time to hit the details. (But I certainly would have liked to see what 20 more degrees of intake and exhaust duration would have brought to the table!!....LOL). Maybe CTM (Cap'n Torque Master) will untie my hands a little next year and be in search of more of the all mighty high RPM ponies. It will start with a face like this.... and a nagging thought in the back of his head that says....what if we added 5 or 10 more degrees of duration....what if I swapped my 78 for a 90 mm FAST.....

Gotta love the mod bug!

Regards to all,
Tony M.

PS....Although Tim already had a set of long tubes I suggested (strongly....LOL) that he purchase the 1.75 QTP's with the merge collecters. I honestly feel these are one of the best headers on the market currently for an F-Body....especially a 346 or a larger motor that wants to place an emphasis on low and midrange power which is obviously the case here. I'm confident that header was a contributing factor which helped us achieve the results we did.

 

Impressive as normal!

 

very nice tony and the car sounds real good

 

First i'd like to say Congrats to the Tim (the owner) & EPP crew considering it was on Mustang Dyno & thru a power robbing 4.10 Moser 12 bolt & mainly on the tiny CAM

As usual tony plenty of valuable info & facts that most of LS1TECH.com members lacking for & personally i really appreciated Tony cause everyday i learn more & more from the knowledgeable ppl like you on this great forum so keep it up gentlemen & way to go

BTW Bob it's your turn to post the waiting Graph !!!

peace

 

what if the duration was in the 240/244 range woud the lift stay the same?? or would you run a little more lift like .595/.602 and lsa 110? ?? how do you think this would have changed the results as far as power and tq? would it have carried thru the higher rpms? im looking for something similar the results that were gained in the mid range but i do wrap my car out to redline and would like to see the power stay on up to redline? any suggestions?

motor is a LS2 403, 4" eagle, H-beam eagle rods 6.125, diamond pistons -11cc total, i was told by the builder if i were to use LS6 heads NONMILLED compression would be 10.8:1. Going in a '04 Z06

Precision Porting and Coatings
Dart 225 stage 3
Intake runner = 225 CC
Exhaust Runner = 80 CC
Comb chamber = 62CC Coated
Intake valve = 2.055" Coated
Exh Valve=1.60" Coated

intake
296@.550
305@.600
exhaust
227@.550
229@.600


Springs = CC 918- i know with the springs that are in the heads going with more than a .600 lift ill need to upgrade the springs.
Seat Press = 135 LBS

LS6 unported intake and ported TB will be used
this is a budget set up, so the headers will be TSP 1- 3/4, already have a bassani Xpipe that will be cut to fit to the headers and a corsa indy cat back, no cats.

 

Good thing that engine did not have 243,s or some patriots or we would be looking for the horsepower left on the table because the cheap heads just do not work.

 

wow he gained almost 100tq all the way through the mid-range. that looks promising for the LS2 guys. good work!

 

Tony,
Can you give use more info about these custom 205 heads? They mention that Tim sent the heads back to you to be reworked. What was the final intake port size after you reworked the 205 heads? Also what was his static compression ratio with the pictured flat top pistons and 205 heads...did you enlarge the combustion chambers?

 

Nice setup Tony.I would love to see what the 225's would do on that motor. I just went over a graph we have here.Pretty much the same motor -408ci with your AFR 225's and a 218/230 Cam on a 114 duration.The graph look identical to your's but our's is only 8.5-1 compression and a LS6 intake. Bet the 225's will give it some more across the range

 

The majority of the work I did was focused in the chambers reshaping them and unshrouding the valves in the process to take better advantage of the 4" larger bore. This made a big improvement in the low and midlift flow and the exhaust flow carried most of the gains all the way to .600 lift. The port volume didnt change at all which obviously kept the airspeed high. The chambers did increase in volume (approxmately 68 cc's finished) from the work which also put our CR exactly where we wanted it to be at about 11.0 to one.

Don (Slowhawk)....I think with the chamber improvement made to the 205 the difference in usable airflow with this particular engine wouldn't have been that much, plus there is no question the part throttle performance would have suffered with the larger runner and the SOTP part throttle TQ is really what Tim (the owner) was after. Would it have made slightly more power everywhere with the 225's at WOT??....probably so, but there is no question in my mind that the 205's were just what the Dr. ordered for Tim's goals. Considering a much larger more "typical" cam (say a 244/248) would have easily added 40-50 HP upstairs (probably giving up 10-15 ft/lbs peak), that would have put the output of this engine approaching 550 RWHP with the 205's (albeit reworked a little with the ported FAST to compliment). Either way you slice it this project was a homerun in every sense of the word and ultimately Tim got the package he craved now.....if his goals change a year from now he's a camshaft swap away from making stupid power with all the same components.

Good stuff....I wish I could have had the opportunity to drive this thing. Tim PM'ed me over the weekend and he says less than half throttle starts the tires squealing in first now matter what RPM he squeezes the trigger at....he seemed pretty jazzed to say the least. I bet with some sticky tires this car would go high tens in decent air....for a car that drives around as docile as a stocker with immense TQ available at almost any RPM it really may be the ultimate pump gas 402 combination for anyone truly in search of a real driver that can still haul the mail. Hell....I bet it still gets low mid twenties MPG cruising down the freeway if you could manage to keep your foot out of it for a couple of hours in a row....but with all the usable TQ this thing has that would be a serious exercise in self control!!



Later,
Tony

 

hmm. why 1.75 headers?? I lost a ton of tq on my setup when I swapped to them. honestly, that doesn't seem to be that flat of a tq 'curve'. I would have expected damn near a straight line. kinda dissaointing to me

 

that set up sounds bad ***......so what kinda power would you expect out of the same motor with a bigger cam and 225's?

 

The results are anything but disappointing....LOL

Find another pump gas 402 that makes close to 450-460 RWTQ @ 2900 RPM! (corrected approximation for typical DynoJet #'s). I would say the average 402 almost makes close to that peak some 2000 RPM later. A 1.875 header would have given up 30 ft/lbs at that RPM. Don't forget our mission here was to maximize performance from off idle to 5000 RPM's. In hindsight looking at the gragh and his goals I should have put more advance in the cam, although I would leave it just the way it is. The perfect daily driver and still able to pull big numbers and not fall off a cliff at high RPM. Even at 6600 long after you would have anticipated this combo to run out of breath it is still within 40 HP of its peak number.


The reason it doesn't look more like a table top is the pull was started much lower than most (2000 RPM's) to see how well we did at producing low RPM TQ (our goal) where its difficult for any pump gas engine to exhibit much TQ regardless of displacement. It makes within 25 ft/lbs of its peak TQ output (approx 505 ft/bs. DynoJet corrected) for just about 2000 RPM's between 3400 and 5300, exactly where a guy like Tim will use it the most with spirited around town type driving.

I could show you the dyno gragh of my highly optimized 383 which has a very flat TQ curve and the funny thing is I will see a gain of almost 60 ft/lbs to my peak TQ figure if I compare 3500 and 5500....Even as early as 2900 Tim's combo is only about 45 ft/lbs from his peak which occurs around 4600 or so.

Bottom line is its kind of an optical illusion regarding not being a flat curve...eliminate the 2-3000 part of the pull and the curve would appear to be very flat....especially because it would be stretched out. And the larger tube headers would have knocked the bottom right out from under this combo only to show a few more peak HP....both average power and TQ would have been much lower if you were to evaluate the numbers from say 2 to 6K.

I'm going to see if Bob @ EPP can repost the gragh starting from say 3000 RPM's, what I would consider more typical of the graghs you usually see.

Thanks,
Tony

 

Tony,I'm definitely on the same page as you.What alot of people don't see is part throttle power.The smaller Cam,small runner head setup would provide a killer throttle/low rpm power.The car has kickass AVERAGE power. After doing a few Strokers like this myself which most had FI added to I'm definitely interested in doing a small Cam/head/408ci motor in my wifes truck

On a side note,the 408 I listed above peaked at 5400rpm but also makes 800hp/800tq to the wheels (by 4500rpm)with a Turbo (15lb's) on 100% 93octain and gets beat to crap daily --never a problem

 

It's a com'n.

 

I'll see what we can do, Tony. Bob

 

From Tim Farrell, the owner of this Firehawk.



Hi Bob!
I've driven it around town a bit now and this thing is a total monster. There is so much power on tap in 2nd and 3rd gear that I don't think you could really have any more power and have it be real streetable. It is the perfect combination of torque, power, and low rpm driveability that anyone could want. Man, when this thing is in second gear and at about 20 mph it feels like you could beat a superbike. I couldn't be more happy. Thanks for all the work you guys did. If you could give a special thanks to Brent for me I would appreciate it. Also, I've been following Tony and your threads...Pretty awesome....People seem to be pretty impressed with the project. Take care Bob. Anybody asks me about a performance shop I'll be sending them your way.

 

TQ!!! good lord that is a beast...

Congrats to the owner!

 

Well Tony you have got me thinking about my cam selection again. Should I go bigger (G5X4) for more peak hp, or should I get you to suggest something to Lou (Gigliotti) on the smaller side and make more power sooner for a longer time?? These cam choices are very confusing. What works on one may not work on mine. I know the G5X3 is a proven monster, and everyone that has the G5X4 say its even better. I really want to see 500 rwhp using the G5X4 and your ported 90/90 setup. Don't know if my car will be able to make the tq early on with a small cam like the the 402 guy did. I've only got the 346. This post may sound like I am rambling, but I am just confused as to the direction to take. As for now, I am probably staying with the G5X4, or something custom that Lou Gigliotti specs out for me. Any input is welcome.

Thanks for a good read Tony, as usual full of good info.

 

sorry Tony, brain fart on my end. for some reason I was thinking 1.75 was 1 7/8 completely agree with you on the header sizing.

I see your point on the 'optical illusion' you can take almost any graph and and change the scaling and rpm shown to make it look flatter or peakier.