utvolman99 Posted March 3, 2006 Share Posted March 3, 2006 I have a 73 240 355 project about half way complete. I am regaining some of the itch to finish it. One thing though that I have really been wondering is if I made the right decision with this car. I am seeing more and more very quick L6 cars with a 280ZX Turbo engine. I think that swap would of been much easier and much much cheaper! I was wondering though about performance? I know we are all one big happy family here and am not looking for a V8 vs. Turbo thread. What I am looking for here is what kind of performance/drivability should I have verses the performance/drivability I would of gotten with a turbo Six... Here is my setup... 355 Chevy small block Dart Iron Eagle 215 Heads with a quick home port and polish Competition Cams Xtreme Energy solid lifter 256/268 Victor Jr. Intake Holley 750 Vac secondary Eagle forged rods Hypereutectic pistons 9.3 - 1 compression ratio Stock 700R4 with Stock Lockup converter R200 Diff with 3.73 gears My desk top dyno tells me that I should be pumping out about 420 HP and around 440ftlbs of torque... give it to me straight... Quote Link to comment Share on other sites More sharing options...
Lason Posted March 3, 2006 Share Posted March 3, 2006 I dont see being able to get that kind of power reliably out of a turbo I6. If you already got the SBC conversion underway I would stick to it IMO. Quote Link to comment Share on other sites More sharing options...
280zwitha383 Posted March 3, 2006 Share Posted March 3, 2006 I've got almost the same setup except mine's stroked and it runs 10:1 compression. I couldn't tell you how close the cam is to yours; but the engine is in my 280zx with a 3.90 rearend and it's pretty ballsy. I don't know how well those heads are going to run on a 355 with 9.3 compression though. They're a bit much I would think but with the 3.70 rearend and an overdrive you might just love it. Let us know how it comes out! Quote Link to comment Share on other sites More sharing options...
nazar Posted March 3, 2006 Share Posted March 3, 2006 desktop dynos lie, dont get too excited Quote Link to comment Share on other sites More sharing options...
utvolman99 Posted March 3, 2006 Author Share Posted March 3, 2006 I dont see being able to get that kind of power reliably out of a turbo I6. If you already got the SBC conversion underway I would stick to it IMO. I do want to clear one thing up about my HP numbers. That is 420 HP at the flywheel so I am estimating somewhere between 315 and 345 RWHP and 335 - 370 RWft-lbs of torque. I know that on the L6 board they are saying that the L28T is good to around 400 RWHP... Quote Link to comment Share on other sites More sharing options...
Lason Posted March 3, 2006 Share Posted March 3, 2006 yeah but dollar for dollar I can say that it is easier to get more power out of larger displacement motors. If you want to make it even then throw a hairdryer on your SBC and turn the knob a lil if you ever get bored. Quote Link to comment Share on other sites More sharing options...
Scottie-GNZ Posted March 3, 2006 Share Posted March 3, 2006 I dont see being able to get that kind of power reliably out of a turbo I6. HUH? Why on earth do you think an L28ET with the proper mods (bolt-ons) would be unreliable at 315-345rwhp? Quote Link to comment Share on other sites More sharing options...
Guest T1 rider Posted March 4, 2006 Share Posted March 4, 2006 I have a talon right now capable of 450 whp. I drive it around at about 320whp and put 10,000 miles on it Quote Link to comment Share on other sites More sharing options...
tfreer85 Posted March 4, 2006 Share Posted March 4, 2006 HUH? Why on earth do you think an L28ET with the proper mods (bolt-ons) would be unreliable at 315-345rwhp? Ditto (I agree), if you've never really looked into the mid-to-high powered L28ET's out there then don't make blanket statements that they are not reliable or as reliable. There are several members in the 315-345rwhp that use their cars as daily drivers. I think Tim Z is putting down 500rwph and is going to be using his as a daily. You're looking at 2 completely different engines with two completely different combustion characteristics, head design, etc. The reliability of any engine relies on the parts and dollar. Its like SuperDan has said in his signature: You can choose any two: 1) Cheap 2) Reliable 3) Fast Tyson Quote Link to comment Share on other sites More sharing options...
JMortensen Posted March 4, 2006 Share Posted March 4, 2006 Scottie mentioned BOLT ONS, treefr85 is talking about TimZ's engine, which has a lot more than bolt ons. I think Scottie is right though, 350whp out of the stock L28ET longblock is not hard to do. The main difference that I can see is going to be driveability. If you're pushing the boost to get max hp you're probably going to have a big turbo on there, and as a result you'll be "suffering" from turbo lag. Might not matter in a drag race situation and some people actually like the feeling of the turbo kicking in, but for a daily driver or even more so in an autox or road course car I'll take the NA V8 that makes 400 hp over the L28ET that makes 400 hp anyday. I have never seen a fast turboed Z at an autox. That doesn't mean they don't exist, just that I haven't seen them, and I've seen probably more than 10 of them now both VG30 turbos and L28ETs. What that means to me is that it's hard to make a turbo Z as fast as an NA Z at an autox. If you're comparing boosted to boosted, I'll take the V8 running 5 psi that makes 400 hp vs the L28ET that runs 20 psi to make 400 hp anyday (in terms of driveability). Bigger the turbo, the worse the lag has always been my experience, and I've driven quite a few turboed cars, including some pushing 20 or more psi. Quote Link to comment Share on other sites More sharing options...
LS1 240Z Posted March 4, 2006 Share Posted March 4, 2006 You can choose any two:1) Cheap 2) Reliable 3) Fast Tyson or you can choose all 3 if you use an LS1 Quote Link to comment Share on other sites More sharing options...
Pop N Wood Posted March 4, 2006 Share Posted March 4, 2006 or you can choose all 3 if you use an LS1 I guess cheap is in the eye of the beholder Quote Link to comment Share on other sites More sharing options...
Pyro Posted March 5, 2006 Share Posted March 5, 2006 You need a lot more compression. I run 11:1 cr with a slightly small cam than yours. And I use 93 octane with 38 degrees of timing with no detonation. You need a 3000+ converter for that cam. And your 3.70 diff needs to be a 3.90 or 4.11. If the cam is 256/268 advertised duration then you gear, stock converter, and compression are just right. But your heads are too big if the cam specs are advertised duration. A 215cc intake port is a pure drag racing head for a 350. I use the dart 200cc on my street/strip Z. I tired the 700R and hated it!!! Nothing but problems with it. Ended up with a GM T5 and it works great. My 240 runs 11.7's at 120mph all motor, and 10.7's at 135 with 150HP of N20. But at this power level it eats up diffs and axles. Once a Z gets into the 11's it is time to upgrade to a solid rear axle and a 4 link. Quote Link to comment Share on other sites More sharing options...
utvolman99 Posted March 6, 2006 Author Share Posted March 6, 2006 just to see how it runs before I add a stall or change heads... This is a build I came up with a long time ago two years ago with the help of grumpyvette (I think he still posts on here?). The idea was that because this is such a light car the engine is built a little towards the higher end than normal. I don't think I will miss the low end torque with the first gear in the 700R4... However, I would like to eventually make the switch to the WCT5 or T56. With that said, you can't beat $75 for a good working 700R4! Quote Link to comment Share on other sites More sharing options...
LS1 240Z Posted March 7, 2006 Share Posted March 7, 2006 I guess cheap is in the eye of the beholder i spent $2500 to rebuild a 350 and 700R4 (with me doing all the labor for the motor and $700 of that was having someone else rebuild a 700R4) you can easily pick up a LS1 and 4L60E for $2500 and it would cost the same to swap an LS1 in as swapping in a SBC. in additon the SBC wont make as much hp or the same gas milage or be as reliable as an LS1. there is a reason why you see LS1s in just about anything you could possibly think of.. Quote Link to comment Share on other sites More sharing options...
jt1 Posted March 7, 2006 Share Posted March 7, 2006 Either a V8 or a turbo L6 can be built for dependability and drivabilty, and to whatever horsepower level your budget will support. So, the bottom line is, build what you want! The V8 will probably give a flatter torque curve and be easier to get running and tuned, especially if you're already halfway there. John Quote Link to comment Share on other sites More sharing options...
frank280zx Posted March 7, 2006 Share Posted March 7, 2006 Scottie mentioned BOLT ONS' date=' treefr85 is talking about TimZ's engine, which has a lot more than bolt ons. I think Scottie is right though, 350whp out of the stock L28ET longblock is not hard to do. The main difference that I can see is going to be driveability. If you're pushing the boost to get max hp you're probably going to have a big turbo on there, and as a result you'll be "suffering" from turbo lag. Might not matter in a drag race situation and some people actually like the feeling of the turbo kicking in, but for a daily driver or even more so in an autox or road course car I'll take the NA V8 that makes 400 hp over the L28ET that makes 400 hp anyday. I have never seen a fast turboed Z at an autox. That doesn't mean they don't exist, just that I haven't seen them, and I've seen probably more than 10 of them now both VG30 turbos and L28ETs. What that means to me is that it's hard to make a turbo Z as fast as an NA Z at an autox. If you're comparing boosted to boosted, I'll take the V8 running 5 psi that makes 400 hp vs the L28ET that runs 20 psi to make 400 hp anyday (in terms of driveability). Bigger the turbo, the worse the lag has always been my experience, and I've driven quite a few turboed cars, including some pushing 20 or more psi.[/quote'] You only get lag when you have to big of a exhaust AR or tot little compression.. you can make a a nice flat curve with a boosted car aswel. It just seems to be the big assumption that you need a huge AR .. given for top end HP you might.. but not for a flat curve! ( ok not as torque happy as a v8 by far but still! ) Quote Link to comment Share on other sites More sharing options...
JMortensen Posted March 7, 2006 Share Posted March 7, 2006 You only get lag when you have to big of a exhaust AR or tot little compression.. you can make a a nice flat curve with a boosted car aswel. It just seems to be the big assumption that you need a huge AR .. given for top end HP you might.. but not for a flat curve! Right, so a Volvo 850T which runs 5 psi boost and 10.5:1 compression or something like that has very little lag, and I realize this as I used to work for a Volvo dealer in the mid 90's and drove them all the time. I think the 850T would have to qualify as the least laggy turbo I've ever driven. Actually they're a lot of fun until they burn an exhaust valve. But when you're looking to extract 400 hp out of an L28 you're going to be pushing a LOT more boost with a lot lower compression, which is why I said I'd rather drive the V8 turbo pushing 5 lbs of boost to get 400 hp than the L28 pushing 20lbs to get the same power. That was the problem which utvolman99 was asking us to address, right? Quote Link to comment Share on other sites More sharing options...
frank280zx Posted March 7, 2006 Share Posted March 7, 2006 I agree a v8 is easy bang for $.. as 300hp is a stock combo from the crate ... However turboes can be made making 350 to the wheels with a small AR.. so not the most lag ... Im really curious what a v8 z would feel like, as in holland... well you dont see them Quote Link to comment Share on other sites More sharing options...
Pop N Wood Posted March 7, 2006 Share Posted March 7, 2006 i spent $2500 to rebuild a 350 and 700R4 (with me doing all the labor for the motor and $700 of that was having someone else rebuild a 700R4) you can easily pick up a LS1 and 4L60E for $2500 and it would cost the same to swap an LS1 in as swapping in a SBC. in additon the SBC wont make as much hp or the same gas milage or be as reliable as an LS1. there is a reason why you see LS1s in just about anything you could possibly think of.. I am about to do an LS1 swap into a 240. My estimated budget is between 7 to 8 thousand right now. That is just the stuff I know about to make the swap. No suspension, brakes, paint and what not. Just engine & T56, mounts, hoses, driveshaft, exhaust, headers, instrumentation, HP Tuner, tank, fuel lines, service manual and an engine hoist. If I believe what everyone says about budgets, this one is on the low side. Once it is running I can worry about budgeting for chassis braces and 36 year old stub axles. Fuel injection definitely adds cost and complexity over a carbed set up. Early (98) LS1's with auto and 97K miles can be had for what you say. A late model F body LS1/T56 combo (2001 or 2002) with reasonably low miles typically run over $4k. http://stores.ebay.com/Fparts_LS1-LS6-LS2-Engines The extra 2 grand for the better engine and T56 seems like money well spent to me. I don't have the luxury of thinking "could probably". I am going to do this so I need to be realistic. 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.