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sliding | What intake for high end 383? | ||
Senior Guru
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I wouldn't like this to become another pissing match about FI vs carb.
Rather than that, I'd like to hear your opinion in which way would you go if you were in my situation. So, without too much details, engine will be 383, Callies crank, Carillo rods, JE or Mahle pistons, AFR 210's, with ~7500 redline. Behind it will be full manual converted 700r4 with 2800 stall and 3.73 gears. I'll probably go with 3200-3500 stall later. Car will be about 50:50 street/road race car. I really don't care about any street stuff (comfort, A/C.........). Only thing that I won't from it on the street is for the engine to run good. Idle will be rough and it won't be very alive under 2500 or 3000 but I want it to be drivable. Now, with all that said, I'm considering which way should I go, intake wise? Intake manifold will probably be Victor Jr. in either case, but I don't know if I should go with road race preped carb or FI with 4bbl TB?! I know that FI has a lot of benefits, but I don't have any experienced tuner anywhere near and I don't feel like learning and doing it all by myself. It would take too much time and any mistake (and I'm sure that there would be some) could be very expensive. Also, FI is much more expensive. For $1000 I can get a state of the art carb, and with that money I'm not even near a good FI. Only FI that I've recently seen and looks interesting is FAST EZ-EFI: [URL="http://www.fuelairspark.com/ezefi/default.asp"]http://www.fuelairspark.com/ezefi/default.asp[/URL] But it's a new system so I'm not really sure how good it would work, especially with a seriouslly cammed engine. What do you guys think? What are your experiences or opinions? |
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Posted on: 2009/12/1 10:07
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'90 L98 auto with a lot of mods |
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anesthes | Re: What intake for high end 383? | ||
Master Guru
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I like EFI if it is in the budget. With that said, Fast EZ-EFI gives up power over a carb.. Why? No idea, probably has to do with the crazy throttle body.
A victor EFI with a 4bbl throttle body, can make tons of power if you know how to tune.. If you decide to convert a victor jr. to multiport, you need to make sure the injector angle is good otherwise you'll be dropping fuel on the floor of the port where there is not enough air flow to atomize it properly. Honestly, you should already know the answer based on your abilities. Tuning a motor is tuning a motor, the question is can you tune EFI and can you tune a carb. Given that WOT performance should be the same since your going to dial in whatever AFR gets the best power, it should be a simple matter of your comfort level in tuning and if you need some of the features EFI provides, such as IAC, FAN, and timing control under varried conditions. -- Joe |
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Posted on: 2009/12/1 11:28
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'79 Z28. 412 CID, NP 833 transmission, 3.73 10.5" rear end. |
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cuisinartvette | Re: What intake for high end 383? | ||
Elite Guru
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What size cam?
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Posted on: 2009/12/1 16:06
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sliding | Re: What intake for high end 383? | ||
Senior Guru
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Posted on: 2009/12/1 20:27
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'90 L98 auto with a lot of mods |
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rklessdriver | Re: What intake for high end 383? | ||
Senior Guru
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I would be using a 2925 Super Victor or similar sized intake on an engine that big, turning that many RPM (actully I am). A Victor Jr has too small of runner cross section and too low of a floor entry angle in the plenmum for a big motor with big runner low port cyl heads like the 210 AFR. If you've already got the Victor Jr - it can be ported to work OK but the 2925 or similar will always be a better choice.
An AED 750 or 850 HO carb on top of that 2925 intake is probally the easiest and cheapest option for power. On the EFI side of the house, you've got a basket full of electronics stuff to choose from. Accel DFI, FAST.... For the intake I'd recommend the 2925 intake w/injector bungs welded in the runner (like I have).... or the Pro Products Super Hurricane EFI, if you don't have anybody w/alum welding and machining/fabrication skills availiable. Its a pretty nice intake for the money and you can buy it turn key with fuel rails, lines and regulator. You have to watch for their "Chinese QC" but most of the time their intakes are OK. http://www.wotperformance.com/store/product.php?productid=16159 You have your choice with throttle bodies. A 4bbl base plate type is the easiest. Or you could have an elbow fabricated up and run a 90mm LSX type single blade TB (I wish I would have went this route). Or like me have an elbow fabbed up and run the stock type L98/LTX TB (I wish I would have NOT went this route)... One other thing. If your turning it 7500RPM your going to need more stall than 3500. I'd suggest a 38-4200rpm converter. Neither of those camshafts will come close to making any power above 6500RPM in a 380 inch engine. You need to look at something with at least 10* more duration (advertised and @.050). Will |
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Posted on: 2009/12/2 2:02
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1984 Corvette. 434 SBC with a Powerglide. Best pass - 8.48@160MPH 1.23 60ft on MT 275/60R15 Radials. 1972 Corvette. LS5 454 BBC with M20 4 speed. Best Pass - Doing good to just pass a gas station. |
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cuisinartvette | Re: What intake for high end 383? | ||
Elite Guru
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ANother vote for the Super Vic, fantastic intake.
IMO the Victor not so much (its not bad mby any means though), reposnds well to work though. |
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Posted on: 2009/12/2 2:55
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sliding | Re: What intake for high end 383? | ||
Senior Guru
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Well, I did put that 7500 redline here, but what I'm really
aiming for is ~6800-6900rpm peak HP and shift points arround 7200-7300 rpm. As I said, I'm not sure about the cam yet. I don't want the car to be totally useless on the street. If that means that I'll have to sacrifice a few hundred rpms on the top...... I know that even higher converter would be good, but I'm not into drag racing at all, and on the track my converter is locked most of the time anyway. And using 4000 stall TC on the street would be overkill (IMHO, correct me if I'm wrong). With rpm ranges above, weakest point is 1-2 shift where rpms drop from 7200 to ~3800 (check graph), and 2-3 and 3-4 shifts should keep revs over 4000. But anyway, all the tracks here are configured that way, that 2nd and 3rd gear are only thing that I can use. As for that 2925 super victor. Will that intake clear stock corvette hood? |
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Posted on: 2009/12/2 13:31
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'90 L98 auto with a lot of mods |
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rklessdriver | Re: What intake for high end 383? | ||
Senior Guru
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Quote:
With a sheet metal elbow it will clear fine. If you had a 3 1/2" or less thick 4bbl base plate style TB it would also clear but you'd have no room to run an air cleaner. Here is a pic of mine w/the elbow attached. [IMG]http://i50.photobucket.com/albums/f303/rklessdriver/Corvette/DSC00941.jpg[/IMG] If I could do it again, the only thing I would change is running an LSX TB instead of the L98/LTX style. That AS&M Mono Blade I have now is a nice peice but very pricey and there are LSX TB options out there that flow just as much (some more) - for half the cost. Will |
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Posted on: 2009/12/2 19:01
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1984 Corvette. 434 SBC with a Powerglide. Best pass - 8.48@160MPH 1.23 60ft on MT 275/60R15 Radials. 1972 Corvette. LS5 454 BBC with M20 4 speed. Best Pass - Doing good to just pass a gas station. |
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sliding | Re: What intake for high end 383? | ||
Senior Guru
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Will, how big is your cam and what power does your engine make? How high do you rev it?
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Posted on: 2009/12/2 19:44
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rklessdriver | Re: What intake for high end 383? | ||
Senior Guru
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The cam is a hyd roller and not really that big.
288/292 Advertised Duration 242/246 Duration @ .050 .620/.620 1.7/1.7 rockers 106 ICL with 110 LSA It makes peak HP @6800rpm. I turn it 7200rpm on the gear change (6spd) and the rev limiter is set at 7400rpm. The best power it made on a chassis dyno (Dyno Jet) was 478RWHP - SAE corrected. I have some dyno sheets scanned from some "trouble shooting" pulls we did right before I took the motor apart (it had a bunch of broke valve springs) and it still was making 440RWHP at only 5200RPM. The car ran well and had a lot of power - althou it was gradually loosing more and more. I never thought the engine made the kind of power it should have from the start and once we took it apart to make some changes, we discoverd the bad valve springs... Since then it has had the compression bumped from 10.6 to 11.66, the intake manifold was fully ported (orginally only port matched) and the valve springs were changed. I have not had it back on a dyno after these changes but need to... The intake and compression bump should be worth quite a bit of power. Will |
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Posted on: 2009/12/2 23:52
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_________________
1984 Corvette. 434 SBC with a Powerglide. Best pass - 8.48@160MPH 1.23 60ft on MT 275/60R15 Radials. 1972 Corvette. LS5 454 BBC with M20 4 speed. Best Pass - Doing good to just pass a gas station. |
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1989GTA | Re: What intake for high end 383? | ||
Guru
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"Mike Jones Custom hyd roller"
The secret is slowly getting out there. |
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Posted on: 2009/12/3 3:41
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BillH | Re: What intake for high end 383? | ||
The Stig Moderator
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Quote:
Just my $0.02, but most of the V8 roadrace cars here aren't reving that high. Most club racers want the motor to last a full season. One half hour race will see 350+ redlines (shifts). Plus whatever you run during practice and qualifing. Most are probably shifting at 6,800 or lower. We have the vintage Nascar shift lites set low like this to keep th rebuilds down. And we generally set the shift point to peak torque, not peak HP. Torque is responsible for fast laptimes not horsepower. Not using 1st is normal. Four speed manual cars may use 1st in one (maybe 2) corners on any given track but 6 speed cars never see 1st gear, depending on the track, you may not even get into 2ond. |
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Posted on: 2009/12/3 14:37
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Every man dies but not every man lives. |
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sliding | Re: What intake for high end 383? | ||
Senior Guru
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Quote:
What would that be on crank? ~550? If only I could copy/paste those numbers to my engine. And how do you rev it so high with hydraulic lifters? |
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Posted on: 2009/12/3 16:21
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'90 L98 auto with a lot of mods |
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cuisinartvette | Re: What intake for high end 383? | ||
Elite Guru
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Some use a trick lifter with a lot of spring for class racing reqiring a hydraulic cam. I am not being negative about WIll or is his motor as he knows his way around them but I would be petrified to run a HR that high, its a matter of time before you have a valvespring failure or encounter lifter pump up resulting in a tagged piston.
At that point Id go solid, just an opinion |
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Posted on: 2009/12/3 17:02
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sliding | Re: What intake for high end 383? | ||
Senior Guru
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I'll go solid for sure. I was just wondering, because
it sounds really high for hydraulic. But either way, I'm impressed with numbers. Will, how is that car on the street. I know that you have manual, but how is drivability? At what rpms does it become alive? How many miles do you have on it, and how much do you expect to make with it? |
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Posted on: 2009/12/3 17:43
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'90 L98 auto with a lot of mods |
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rklessdriver | Re: What intake for high end 383? | ||
Senior Guru
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Quote:
What would that be on crank? ~550? It's a bit more than that but how much more I don't know for sure. The HP numbers I have from our Stuska engine dyno where it was dyno'd with an AED 750HO carb and regular distributor/MSD box ignition, open headers ect are kinda worthless to compare by. I do know even little things like tire pressure can vary chassis HP numbers as much as 20 or so HP on a street car.... IMO it was some where around 570-580HP as installed in the car before the valve springs took a dump but thats just a guess. Quote: how do you rev it so high with hydraulic lifters? Crusin is correct. I do have special lifters mfgr'd by MOREL and a lot of valve spring. I also have an AFR Hydra Rev Kit that we modified to fit the MOREL lifters. The hyd cam was a "learing experiment challenge" for me to see for my self just what was possible and I wouldn't recommend anyone try to do what I'm doing without knowing that it cost me a LOT OF MONEY, time, heartbreak and probally will for every day I run it. Quote: Will, how is that car on the street. I know that you It actually pretty docil at low RPM. I drive it around all the time. Even in DC traffic its fairly easy to drive. Some cam surge until 2500 or so RPM but my tuner did a great job with pulling timing out of it at low throttle angles so it cruises in 6th gear at 1800rpm on the hyw perfect. You can't tell anything about how much motor it has until you get past about 1/2 throttle. Once you pass that point with the throttle its like someone clicked a light switch. The car just wakes up and you can tell you've done something. Power is explosive at WOT. TQ is about 300ftlbs @2500RPM, then 350ftlbs@3200rpm, then 405ftlbs@3800, then table top flat 405ftlbs till it falls off. It really has more power than a stock LTX at any RPM so it's "alive" anytime you open the throttle but around 3500rpm it takes on its tire destroying personality. With the 6spd I've lugged it below 2000RPM in 3rd and 4th gears just to see if it would be a dog or what - and it's not. It pulls cleanly and smoothly until it comes up on the cam then explodes with power and pins you in the seat. So far I've tried a 4.11 rear gear, a 3.90 rear gear (currently in the car) and the stock 3.45 rear gear and can't tell much difference except oddly with the 4.11 you can go WOT in low gear over 400RPM and the car don't seem to spin the Drag Radials until the gear change and then settles down quickly once in 2nd gear... with the 3.90 and 3.45 I can feel it wheel hop a bit then just spin them for a good while once in 2nd gear... odd but thats what it does. Regular radials are a joke. So far I have about 1500miles on the motor since the repairs/upgrades. I expect it go around 500RWHP once its re-tuned for the compression bump, monoblade and ported intake. Might not make 500 but it will be darn close and I'm fine with that at this point. Will |
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Posted on: 2009/12/4 0:17
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_________________
1984 Corvette. 434 SBC with a Powerglide. Best pass - 8.48@160MPH 1.23 60ft on MT 275/60R15 Radials. 1972 Corvette. LS5 454 BBC with M20 4 speed. Best Pass - Doing good to just pass a gas station. |
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anesthes | Re: What intake for high end 383? | ||
Master Guru
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Quote:
Which is really a solid roller, but he's running hydraulic lifters and some crazy springs and a rev kit to keep it together.. -- Joe |
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Posted on: 2009/12/4 1:16
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sliding | Re: What intake for high end 383? | ||
Senior Guru
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Thank you Will for such detailed post.
I was hearing a lot of stuff that engine that turns 7200-7300 won't be streetable at all, and that it won't last very long. Well, I don't expect to put too many miles on it, but with my 3000 miles/year average, I think that it'll last for quite a while, with good maintenance of course. |
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Posted on: 2009/12/4 15:38
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_________________
'90 L98 auto with a lot of mods |
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cuisinartvette | Re: What intake for high end 383? | ||
Elite Guru
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It will last fine, dont listen that that hogwash. Good parts/machine work etc...Plenty of DDs out there turning over 7k on occasion. Not all day but you get the idea.
Obviously a motor that turns less rpm is prone to last longer but what the hey, ones you can spin up there can be fun. |
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Posted on: 2009/12/4 16:47
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sliding | Re: What intake for high end 383? | ||
Senior Guru
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Quote:
Exactly! |
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Posted on: 2009/12/4 18:32
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'90 L98 auto with a lot of mods |
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