boardkid280z Posted March 12, 2009 Share Posted March 12, 2009 What does EP stand for? Quote Link to comment Share on other sites More sharing options...
sickboy Posted March 16, 2009 Share Posted March 16, 2009 What does EP stand for? E Production (SCCA) Nice numbers Jeff, I've seen your car in action many times, no doubt it's dialed in. For comparison, my car dynoed 253 whp, 232 tq on a Mustang dyno. Specs: 12:1 cr, 3.1 L, N42 with moderate work, Rebello "road race" cam (specs unknown), Mikuni 44s, 3" exhaust, crankfire. So that puts me at 82 hp/liter and you at 96 hp/liter. I've been told by several people that Mustang numbers are consistently lower than Dynojets. There is a Dynojet nearby, so I think the next step is to take a few pulls there and compare them. Quote Link to comment Share on other sites More sharing options...
silver280zx Posted March 28, 2009 Share Posted March 28, 2009 E Production (SCCA) Nice numbers Jeff, I've seen your car in action many times, no doubt it's dialed in. For comparison, my car dynoed 253 whp, 232 tq on a Mustang dyno. Specs: 12:1 cr, 3.1 L, N42 with moderate work, Rebello "road race" cam (specs unknown), Mikuni 44s, 3" exhaust, crankfire. So that puts me at 82 hp/liter and you at 96 hp/liter. I've been told by several people that Mustang numbers are consistently lower than Dynojets. There is a Dynojet nearby, so I think the next step is to take a few pulls there and compare them. Ya mustang dynos supposidly read 15-20 percent lower than dyno jets, at least thats what the guys at Lethal injection in alpharetta ga said at a dyno day i went to. On the mustang dyno, my 79 l28e s130 with a stock motor and your average boltons, plus a ligt flywheel, put down 118whp and 129wtq, so ya if you put down 253whp on a mustang dyno thats impressive. A guy had a mazdaspeed3 turbo at the dyno day that put down 270whp on a dynojet, he put down 190whp on the mustang dyno. Quote Link to comment Share on other sites More sharing options...
Tony D Posted March 28, 2009 Share Posted March 28, 2009 Actually, Z-Ya, Webers and most other similar carbs can be tuned across the power range for partial throttle response and power. It's just that nobody is willing to pay for the time it takes to do that! Custom porting of emulsion tubes and then trial-and-error pulls and partial throttle runs... I have said it before, anybody who professes that 'carbs are easy' hasn't tuned one for competition! Our Weber Power Pulls were like felt-tipped marker sweeps on the dyno chart. The EFI was a bit...er...'notchy' with the same dyno settings (smoothing, etc.) As for engine variation---it exists. Engines produced with identical clearances WILL make different power. Sure, as you tighten clearances the variation should get smaller. Spec Racers are decidedly NOT what this discussion is about. They are PRODUCTION ENGINES and that is the POINT of the class. They have an accepted variation and the class lives within it. When someone wins too much, they tear it down or make him chage from a random pool of spec engines for the class. Wonder why they pick from a random pool of engines? Because statistically it spreads out the odds of the variation equally amongst contestants. Why? Because they know there will be engines in the lot making marginally more than others. But when you are not restricted by class rules (and E-P DOES have rules to comply with that a street engine does not...) then you by logic restrict the output of that engine. Any racing engine can make considerably less than it's street counterpart, simply from this restriction or that. EP Runs EFI, right? Quote Link to comment Share on other sites More sharing options...
Cobra_Tim Posted March 28, 2009 Share Posted March 28, 2009 EP Runs EFI, right? Nope... SUs Quote Link to comment Share on other sites More sharing options...
woldson Posted March 29, 2009 Share Posted March 29, 2009 Actually, Z-Ya, Webers and most other similar carbs can be tuned across the power range for partial throttle response and power. It's just that nobody is willing to pay for the time it takes to do that! Custom porting of emulsion tubes and then trial-and-error pulls and partial throttle runs... I have said it before, anybody who professes that 'carbs are easy' hasn't tuned one for competition! Our Weber Power Pulls were like felt-tipped marker sweeps on the dyno chart. The EFI was a bit...er...'notchy' with the same dyno settings (smoothing, etc.) As for engine variation---it exists. Engines produced with identical clearances WILL make different power. Sure, as you tighten clearances the variation should get smaller. Spec Racers are decidedly NOT what this discussion is about. They are PRODUCTION ENGINES and that is the POINT of the class. They have an accepted variation and the class lives within it. When someone wins too much, they tear it down or make him chage from a random pool of spec engines for the class. Wonder why they pick from a random pool of engines? Because statistically it spreads out the odds of the variation equally amongst contestants. Why? Because they know there will be engines in the lot making marginally more than others. But when you are not restricted by class rules (and E-P DOES have rules to comply with that a street engine does not...) then you by logic restrict the output of that engine. Any racing engine can make considerably less than it's street counterpart, simply from this restriction or that. EP Runs EFI, right? 10 yrs, or so ago, did not Mercedes develop a legal push rod engine for there cars that was whooping competition? Even though it was legal they ended up outlawing it. Had something to do with the fact you could run lager displacement, due to the inferior design of the push rod engine that they over came?? Quote Link to comment Share on other sites More sharing options...
z-ya Posted March 30, 2009 Share Posted March 30, 2009 Actually, Z-Ya, Webers and most other similar carbs can be tuned across the power range for partial throttle response and power. It's just that nobody is willing to pay for the time it takes to do that! Custom porting of emulsion tubes and then trial-and-error pulls and partial throttle runs... I didn't say it can't be done. It just takes a lot of expertise, and a lot of time. My point is that there will most likely be an area in the powerband where the optimal AFR cannot be achieved without affecting other areas. So typically for a racer you will focus on WOT tuning, because for the most part, that is all that matters. Quote Link to comment Share on other sites More sharing options...
Tony D Posted April 1, 2009 Share Posted April 1, 2009 Nope... SUs I think judging by your ending symbol, you got my point. Quote Link to comment Share on other sites More sharing options...
Cobra_Tim Posted April 1, 2009 Share Posted April 1, 2009 I think judging by your ending symbol, you got my point. Latest EP motor off the dyno Quote Link to comment Share on other sites More sharing options...
M.Creer Posted April 3, 2009 Share Posted April 3, 2009 Nice Car. Your engine is clean. I like how it looks. Quote Link to comment Share on other sites More sharing options...
Daeron Posted April 3, 2009 Share Posted April 3, 2009 Nice Car. Your engine is clean. I like how it looks. Heh, not his car. I *think* that is one of Greg Ira's cars.. but Tim has gone out of town for the weekend so unless someone else who knows Ira con confirm/deny that.... Quote Link to comment Share on other sites More sharing options...
M.Creer Posted April 4, 2009 Share Posted April 4, 2009 My mistake I meant Monzter's car and especially the motor. Quote Link to comment Share on other sites More sharing options...
Gollum Posted April 16, 2009 Share Posted April 16, 2009 Regarding the Carb discussion - I'd say that very few carb setups that are street driven will ever reach max power potential like EFI can. Sure you can tune a carb for max power, but it WILL be a sacrifice somewhere else. Even companies like sunbelt, robello, etc won't be giving you an engine with carbs that are tuned perfectly for peak power. They're going to give you what you paid for - a good street motor in most cases. I don't see the torque figures that unbelievable. Sure the cam isn't too extreme, but we all know it's not just about cams. MONZTER has shown well enough that he has an engineer's mind and loves to think things through. Just look at his head, how many people have welded chambers on a street driven Z?.... Also, lets not forget that he's running very low rotating mass. Do you know your rear wheels weights MONZTER? If he's running a R180, with light wheels, with the flywheel and clutch setup he mentioned in this thread he could be putting a very good percentage of his power down to the ground. Also, let's say the dyno might be slightly off (which MONZTER admitted might be possible), if it's only 5% off that would be over 10hp at that level, which adversely affects the estimated crank numbers. Oh, and I've seen well over 100 03' Cobra dynos and you'd be amazed at the factory variances. Engines DO vary, regardless of how tight the tolerances are. That's why many crate engines come with a dyno sheet. Ford rated the Cobra at 390HP, yet there were guys putting over 350 to the ground stock on the same dyno that others on the same day put 340 to the ground on. Everyone in the know admitts that SVT underrated the engine a bit, but most tend to agree it's due to the variables, and they didn't want to get caught in what they'd gotten caught in before, which was people filing lawsuits against Ford because their precious cobra came with 10HP under the rated HP. I would be willing to bet people at sunbelt and rebello feel the same way. It's better to take off 5-10% of their best numbers so that the small variations don't come back to bite them. My personal conclusion though is that with a head and intake as custom as MONZTER's it's apples to oranges to most engines with the same cam. He's running around 11:1 compression correct? He also has insane amounts of quench. Could it be that his flame propagation is just that much better that he's just squeezing a tad more efficiency out of it? I think both dynos prove his torque range though, which to me seems perfectly acceptable for the engine. The fact his rev range seems so good considering the cam is pretty special though. I'd be interested to find out the concrete reason why, but I'm sure it exists. Quote Link to comment Share on other sites More sharing options...
zclubhouse Posted April 16, 2009 Share Posted April 16, 2009 Latest EP motor off the dyno Haha very cool, but good luck getting that one past tech! How does that thing run? Quote Link to comment Share on other sites More sharing options...
Mack Posted April 16, 2009 Share Posted April 16, 2009 I hope that my car will put down similar numbers and I have a 2.8L! I have a very similar delta regrind cam and a maxima N47 head with high quench, giving me a cr of 11.5:1 with flat tops. I just got done with my intake manifold and it will be welded by toimorrow! 41MM (weird I know) ITB set up. and the head is port matched to it. also have a header and 2.5" catless exhaust. Ill be running it with MSII, and I hope to make it to tune it on tuesday next week, right before I leave for MSA. cutting it close I knwo..... ha ha! Quote Link to comment Share on other sites More sharing options...
Tony D Posted April 16, 2009 Share Posted April 16, 2009 "Just look at his head, how many people have welded chambers on a street driven Z?...." I guess I make that at least 2 people here in the USA... In Japan? Back in the 80's almost every hot performance engine making power had a welded N42 in it... I could pick them up in the scrap heap after a spark plug electrode let loose and scarred a chamber, etc, for 3000 yen (scrap value, about $15 at the time!) Got an idea where I got my welded head from??? Quote Link to comment Share on other sites More sharing options...
Gollum Posted April 16, 2009 Share Posted April 16, 2009 "Just look at his head, how many people have welded chambers on a street driven Z?...." I guess I make that at least 2 people here in the USA... In Japan? Back in the 80's almost every hot performance engine making power had a welded N42 in it... I could pick them up in the scrap heap after a spark plug electrode let loose and scarred a chamber, etc, for 3000 yen (scrap value, about $15 at the time!) Got an idea where I got my welded head from??? You booger. You get my point. People with welded chambers are in the minority these days, and you don't see such work advertised with people like rebello. It seems that any time I go to an event with lots of Z purists and they wear "rebello" engine on their sleeve it's more of a bragging right and they can't give you a single detail of their engine other than displacement and what spark system they're running. I'm not mad, upset, angry or anything, my point is that with a custom chamber like that I don't think his head can easily be compared to other engines out there. The head makes the power, and the fact he's making power at such a high rpm with that cam should show how well the head's been worked and matched so that all the parts in the system are working very well together. Quote Link to comment Share on other sites More sharing options...
JustinOlson Posted April 16, 2009 Share Posted April 16, 2009 I want to try the N47 head with high compression piston and E85 for the street. It would be great fun running around with 12:1 + CR. Quote Link to comment Share on other sites More sharing options...
rsicard Posted April 16, 2009 Share Posted April 16, 2009 Robello is not about to give away their secrets when it comes to engine building. If you have been following the threads about quench/squish some of the secrets have already leaked out. Robello is not the only ones to know the secrets of good fast combustion without attendant knock. Quote Link to comment Share on other sites More sharing options...
Tony D Posted April 16, 2009 Share Posted April 16, 2009 It was kind of what I was getting at earlier in the thread as well. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.