Why did you decide to stay with the Datsun L6 motor?

[Gollum]

I have both, '74 260Z with built L6 and '78 280z with a LS1. Different handling.

 

True'r than true.

 

Many people get really caught up in the whole weight balance thing and forget that an integra type R's only handicap at a track isn't it's handling, but it's limited ability to put power down being a FF platform (which still isn't bad with the right setup). That car is over 60% front biased if I recall correctly and handles great. So do well prepped CRX's which again, have almost no weight in the back. Porsches have insane rear weight bias and can still be made to handle like a dream, and do well enough from the factory from most accounts.

 

Point being, setup is far more important than weather or not your engine is 350 or 450 pounds, or three inches farther back.

 

The point of all this is if you are going to autocross your Z, then I suggest you accept very early on that you may never, ever dominate your class as you might hope. If that's the case (as it is for me!), then in the end you won't care what class you're in over your head in -- you will simply love your car and have a blast driving the piss out of it.

 

If that's the case, then figure out what ultimate 'HybridZ' gets your blood boiling and work toward it!

 

And that's where the SR can really shine. It's a fairly easy and affordable swap that doesn't have many downsides. People often say - cheap, fast, reliable, you can only pick two. But what most people don't think about is that those are ALL relative terms. Cheap... compared to what? On what budget? Fast... Compared to a stock Civic or a Zonda? Reliable... Compared to a stock 30 year old Z, or a 90's Honda?

 

So all three of those factors are "meters" in a sense. The SR does well in all categories. It's not the budget of the budget, but for how much power it can make, while being light and compact, and being reliable enough it's doesn't break the bank. The are other options out there, but it's a good one to consider if you're wanting a swap that makes the car easy chassis-tune to handle well. That said, the L6 motor is a road well paved and the setups have already been done time and time again.

[JMortensen]

Well setup S30s dominate FP at the national level. They won't make the cut in any other class at the level. FWIW.

I wish I could find the times, but I think SCCA has removed them from their website. I seem to remember that John Thomas was less than 1/2 second off of the winning XP time, and that's being limited to the L6 and 16x10 wheels. JT is obviously an EXCELLENT driver, but the point is I think the Z could be competitive in XP, especially if the car were built to maximize the rules. I'd probably go KA24DET if I were building one to try and win nats, but I wouldn't be surprised if even my porky 5.3L car at 2250 with no driver could still post up times that compared well to JT's assuming a good enough driver were behind the wheel. I guess I have to attempt to prove that assertion, or it's all just keyboard warrior stuff, but the car should handle pretty good with the way I'm setting it up, and it would have some advantages like wider wheels, rear wing, more power, not that much more weight, etc.

[zredbaron]

Well that was a major thread jack, went from staying with the Stock L6 to swapped motors, weight distribution, and autoxing. Tis the way of Hybridz I guess.

 

Haha, sort of! The reason we're talking about this other stuff is the racing variable, in which classing is law and therefore motor choice is crucial if you want to run in BSP or FP.

 

And Jon, I agree with you about a purpose built S30 being able to dominate XP. My times are rather middle of the pack in XP (Wash DC). Mine will never dominate of course, because I won't cut the fenders. If I ever decide that competition is more important to me than "building my dream car," then I would make it my life's purpose to chase national S30s. In the back of my mind, I honestly don't know what's more appealing, a tuned FP, or an XP L6 monstrosity.

 

That said, however, I'm also under the impression XP is fairly up for grabs right now. That is to say, the class is new enough that no one has truly built a car to the class' potential yet. I didn't go to nationals, though, just regionals.

 

And that's where the SR can really shine. It's a fairly easy and affordable swap that doesn't have many downsides. People often say - cheap, fast, reliable, you can only pick two. But what most people don't think about is that those are ALL relative terms. Cheap... compared to what? On what budget? Fast... Compared to a stock Civic or a Zonda? Reliable... Compared to a stock 30 year old Z, or a 90's Honda?

 

So all three of those factors are "meters" in a sense. The SR does well in all categories. It's not the budget of the budget, but for how much power it can make, while being light and compact, and being reliable enough it's doesn't break the bank. The are other options out there, but it's a good one to consider if you're wanting a swap that makes the car easy chassis-tune to handle well. That said, the L6 motor is a road well paved and the setups have already been done time and time again.

 

I agree with Gollum with everything he said about setup dial-in being most important with getting your car to handle, not weight distribution / balance. Engine weight is not a factor in my mind, I shared my numbers to further quell misplaced concerns.

 

I would point out though, that swapping a non-model specific engine will automatically kick you to SSM or XP in autocross. Sure, you might have a cheap, reliable engine with plenty of power, but SSM and XP expect you to put down some very fast times, and therefore whatever money you saved under your hood will now have to go into getting a 40 year old car to keep up with a highly modified Z06 on slicks 345-385mm wide. Not gonna happen.

 

Cheapest reasonably competitive setup would be a BSP L6 with SUs, headers, electronic ignition, coilovers, camber plates and call it a race car! Stock brakes are more than enough for autocross, especially at the BSP level.

 

Either that or build your dream car and don't worry about it. Those are your choices with autocross!

Edited February 9, 2011 by zredbaron

[HS30-H]

The Datsun 240z dominated it's class in the 70's. In it's SCCA class, it was up against BMW, Alfa Romeo, Porsche, and other well respected sports cars. The 240z beat them all. The $2500 240z was eating $50,000 Porsche's.

 

$50,000? What model of Porsche are you talking about?

[Racer Z]

$50,000? What model of Porsche are you talking about?

 

Sorry. $50,000 including mods.

[HS30-H]

Sorry. $50,000 including mods.

 

But the 240Zs were still "$2,500", right?

 

Those 'Porsche' 914s were sold as VWs outside the USA.......

[Racer Z]

We went to Willow Spring Raceway about six months ago to watch the VARA races. There were all kinds of cars from the late 60's early 70's, all set up like they would have been to run a SCCA event of their time. When I got over to the hot-pits, the cars were gridded up, engines off, waiting for the track to clear. In position 2 was a 240z followed by all the other cars you would expect to see if you traveled back in time. This included a handful of of 240z's as well.

 

When the track cleared and they started their engines, I sure thought the off-pole 240z had a V-8 in it. It was load and lumpy. When they came around from the warm-up lap and got the green flag, the 240z sound like a top-fueler, and took off like one two. I timed her (yes I later learned a lady was driving) at 1:35 laps.

 

I've driven WSIR enough times, and watched enough newer faster cars run WSIR to know that 1:35 is a very respectful lap time. Just for a comparison, we turned a 1:50 in our stock 240z with street tires. The track record is 1:12 set by Mario Andretti in his Indy Car. She was screaming and there were only two other cars that could even think about touching her. She cam in a close second with 3'rd quite a ways behind. I think she lost to a Porsche, but I don't recall now.

 

Later, in the pits, we stopped by their pits and got to look at her car with the hood up. I wanted to see this V-8 powered Datsun. What V-8??? It was a straight six!!! No turbo! L24, L26, L28 or a 3.1 stroker I don't know, but it looked like the L24 in our 240z. I didn't ask any questions, I just gawked and drooled. She was in the GPU class which is the unlimited class, meaning she had done something that put her above the CP class. Carbs and headers is all I could see. No doubt there was big cam in it.

 

After watching her, and the other 240z's run, most with the L24 block, NONE with an engine swap, (I don't consider the L28 to be an engine swap because it bolts in and does not obviously look different), I am convinced that with better driving skills I too can put a lot of other cars to shame with a seemingly stock 240z.

[johnc]

We went to Willow Spring Raceway about six months ago to watch the VARA races. There were all kinds of cars from the late 60's early 70's, all set up like they would have been to run a SCCA event of their time. When I got over to the hot-pits, the cars were gridded up, engines off, waiting for the track to clear. In position 2 was a 240z followed by all the other cars you would expect to see if you traveled back in time. This included a handful of of 240z's as well.

 

When the track cleared and they started their engines, I sure thought the off-pole 240z had a V-8 in it. It was load and lumpy. When they came around from the warm-up lap and got the green flag, the 240z sound like a top-fueler, and took off like one two. I timed her (yes I later learned a lady was driving) at 1:35 laps.

 

I've driven WSIR enough times, and watched enough newer faster cars run WSIR to know that 1:35 is a very respectful lap time. Just for a comparison, we turned a 1:50 in our stock 240z with street tires. The track record is 1:12 set by Mario Andretti in his Indy Car. She was screaming and there were only two other cars that could even think about touching her. She cam in a close second with 3'rd quite a ways behind. I think she lost to a Porsche, but I don't recall now.

 

Later, in the pits, we stopped by their pits and got to look at her car with the hood up. I wanted to see this V-8 powered Datsun. What V-8??? It was a straight six!!! No turbo! L24, L26, L28 or a 3.1 stroker I don't know, but it looked like the L24 in our 240z. I didn't ask any questions, I just gawked and drooled. She was in the GPU class which is the unlimited class, meaning she had done something that put her above the CP class. Carbs and headers is all I could see. No doubt there was big cam in it.

 

After watching her, and the other 240z's run, most with the L24 block, NONE with an engine swap, (I don't consider the L28 to be an engine swap because it bolts in and does not obviously look different), I am convinced that with better driving skills I too can put a lot of other cars to shame with a seemingly stock 240z.

 

Are you comparing current VARA/SVRA/HSR West CP level builds and costs or vintage correct builds and costs from back in the day?

 

If its current level builds then the costs are almost comparable. A typical front running VARA CP3 240Z is a $20K to $40K car - I know, I've done work on Steve Link, Larry Hassler, Chris Cox, and John Wilkin's cars (all front runners in CP3). The typical 911 running in the same class has $30K to $60K invested. The cost difference is normally about 30% between a front running 240Z and 911 in a vintage race build, which isn't that great. The 240Zs are also given a displacement break of .4L (2.4L L6 vs. 2L flat 6 in CP3) and I think the Datsuns weight 100 lbs less.

 

There is no $2,500 240Z running in vintage racing here on the west coast.

[Racer Z]

But the 240Zs were still "$2,500", right?

 

Those 'Porsche' 914s were sold as VWs outside the USA.......

 

The 240z sold new for about $2500. The Porsche for considerable more. Both cars had mods done. In the end, the Porsche's of the day had a modified price tag of $50,000 while the 240z was closer to $20,000. The Porsche drivers were pissed. With all their prestige and money, they were all loosing to this inexpensive car with no class. The rules of the SCCA class stated that they had to use the original block, crank and heads. They could not change the bore and stroke.

 

The 240z dominated EVERYTHING in it's class.

[johnc]

I've driven WSIR enough times, and watched enough newer faster cars run WSIR to know that 1:35 is a very respectful lap time. Just for a comparison, we turned a 1:50 in our stock 240z with street tires. The track record is 1:12 set by Mario Andretti in his Indy Car. She was screaming and there were only two other cars that could even think about touching her. She cam in a close second with 3'rd quite a ways behind. I think she lost to a Porsche, but I don't recall now.

 

 

FYI... the ultimate track record is 1:06.xxx set by Michael Andretti back on March 1987. The SCCA ITS 240Z lap record is a 1:32.xxx set by Bryan Lampe in Rich Maloney's old 240Z. Byran beat all the modified 2.8L, cammed, weber carb'd, 12 to 1 CR, 200 lb. lighter weight, 4 wheel disc, CP3 cars with his stock engine internals, drum braked, SU equipped ITS 240Z.

[johnc]

The 240z sold new for about $2500. The Porsche for considerable more. Both cars had mods done. In the end, the Porsche's of the day had a modified price tag of $50,000 while the 240z was closer to $20,000. The Porsche drivers were pissed. With all their prestige and money, they were all loosing to this inexpensive car with no class. The rules of the SCCA class stated that they had to use the original block, crank and heads. They could not change the bore and stroke.

 

The 240z dominated EVERYTHING in it's class.

 

The 240Z typically sold for $3,500 plus dealer markup. The 911 sold for about $7,500 and the 911S sold for about $8,500.

[Split98]

off the top of my head, last time I checked official SCCA classing, 3000cc displacement is the magic detail. basically if you don't have a stroker, any Z engine combination is allowed up to 3.0L for both BSP and FP.

 

basic [national] SCCA classing and allowable mods for S30s (other than stock):

 

BSP - suspension, seats, camber plates, electronic ignition, etc

SSM - BSP allowances plus > 3.0L engine, turbo, V-8, composite hood, etc.

 

FP - full slicks, significant weight reduction, chassis stiffening, fender flares, etc.

XP - FP allowances plus > 3.0L engine, turbo, V-8, etc.

 

Well setup S30s dominate FP at the national level. They won't make the cut in any other class at the level. FWIW.

Lol, I had that all kinds of backwards (I thought FP was factory). BSP will likely be my goal, as I won't have stacks to pour into this thing until a little later in life. Glad to hear the L28 is allowed, hopefully it's the same for my local events too.

 

Only kink I can see is the harness bar. Was really hoping to install at least a harness bar for DD use to compensate for the lack of airbags.

 

Edit: and I just realized that talking about harness bars completely took this off topic. My apologies.

Edited February 8, 2011 by Split98

[zredbaron]

Lol, I had that all kinds of backwards (I thought FP was factory). BSP will likely be my goal, as I won't have stacks to pour into this thing until a little later in life. Glad to hear the L28 is allowed, hopefully it's the same for my local events too.

 

You really should download the SCCA rules and read up on how cars are classed. Look up the class definitions for "Stock," "Street Prepared," "Street Modified," and "Prepared."

 

http://cms.scca.com/...olo%20Rules.pdf

 

In descending order according to expected raw time (current PAX):

 

ES - E Stock (.825)

BSP - B Street Prepared (.859)

FP - F Prepared (.872)

SSM - Super Street Modified (.875)

XP - X Prepared (.887)

 

PAX-wise, SSM is actually expected to put down a faster time than FP is. SSM and XP are the "wrung whatcha brung" classes that pit all productions cars against each other regardless of letter class. You will fall into these classes if you exceed any class defintions as outlined in the .pdf above. You could also consider this the "ascending budget" list, too. FP and SSM are arguably comparable budgets, depending on what kind of car you create.

 

Read the SCCA Solo Rules, and *THEN* make a class decision based on budget, personal desires, etc. It's expensive and competitively frustrating to do it the other way around like I did.

Edited February 9, 2011 by zredbaron

[JMortensen]

I believe you can run a 240 with an L28 as a 280 in B/SP so long as you meet the weight requirement for a 280. From the rulebook:

 

A vehicle may compete in Street Prepared Category if the preparation

of the vehicle has not exceeded the allowable modifications of Stock

Category, except as specified below. However, the distinction between

different years/models used in Stock Category does not apply in Street

Prepared Category. Example: Porsche 911 models that are listed on

the same line are considered the same.

 

240Z, 260Z, 280Z, 280ZX, &

280ZX Turbo

300ZX Turbo (1984-89)

300ZX Turbo (1990-96)

350Z

 

The way it is listed makes it look like the 280ZX is in there too. I think that the L28ET was determined to be illegal, not sure if what the deal is there.

 

For the record, a winning B/SP car is going to be EXPENSIVE.

[johnc]

I believe you can run a 240 with an L28 as a 280 in B/SP so long as you meet the weight requirement for a 280. From the rulebook:

 

A vehicle may compete in Street Prepared Category if the preparation

of the vehicle has not exceeded the allowable modifications of Stock

Category, except as specified below. However, the distinction between

different years/models used in Stock Category does not apply in Street

Prepared Category. Example: Porsche 911 models that are listed on

the same line are considered the same.

 

240Z, 260Z, 280Z, 280ZX, &

280ZX Turbo

300ZX Turbo (1984-89)

300ZX Turbo (1990-96)

350Z

 

The way it is listed makes it look like the 280ZX is in there too. I think that the L28ET was determined to be illegal, not sure if what the deal is there.

 

For the record, a winning B/SP car is going to be EXPENSIVE.

 

Per an e-mail conversation I had with Brian hammer of SCCA in January, the 240/260/280Z and the 280ZX/280ZXT are correctly listed all on one line. That means you can build a BSP legal 240Z with a 280ZXT engine.

[ModernS30]

I stuck with the L6 because it was what I had for now. I can get a few good deals on some parts and its a good way for me to get the feel of driving a higher powered S30. I don't know where it will go but I may decide upon an LSx/T56 swap in the future. The power, price, weight, and availability are all there. They make for one great platform. Where as the L28 in itself has a poor flowing head. It can make easy power in the under 400 range, but, and this goes really with most engines, venturing past 400 can get quite expensive.

[Racer Z]

Are you comparing current VARA/SVRA/HSR West CP level builds and costs or vintage correct builds and costs from back in the day?

 

John, I am not familiar with SVRA or HSR. I was speaking of cost for SCCA run cars back in the day. Be it big teams like BRE and Bob Sharp, or small unknowns, the 240z proved itself as a track worthy car capable taking on cars with impressive names and even more impressive prices. The SCCA CP class of that day, as does the VARA CP class of today, dictate that the correct block, crank and head be used for the year make and model of car including stock bore and stroke.

[zredbaron]

Thanks for the BSP engine swap allowances clarification, John.

 

For the record, a winning B/SP car is going to be EXPENSIVE.

 

Heck, I'd say a "winning" S30 in any of the classes would be in the big-budget category!

[JMortensen]

Per an e-mail conversation I had with Brian hammer of SCCA in January, the 240/260/280Z and the 280ZX/280ZXT are correctly listed all on one line. That means you can build a BSP legal 240Z with a 280ZXT engine.

Now I can build that L24 powered 280ZX I've been dreaming of...

[dladow]

I bought a relatively clean 1973 240z automatic with a tired 2.4L engine with every intention of swapping in an SBC 355 V8. I scrounged a running 350 that originated in a 1976 Chevrolet pick up and rebuilt it, mildly ported the 882 heads, bought shorty headers, the JTR conversion kit, redid the suspension with stiffer springs, and poly bushings all around, bought a rebuilt Craigslist 7R4 auto trans … and then an early 1974 260z parts car with a trashed rear suspension and ruined interior fell into my lap. I bought it for $400 for its straight rust free removable body parts, but also, it had not been licensed since 1989 and showed only 88K. It had a bone stock 2.6L with a 4 speed.

 

I began to ponder the advantages of swapping in the 260 short block and trans (seeing as how they were now in stock). I could rebuild the engine with simply regrinding the crank, a light hone (the bores were in fantastic shape), new rings, and new bearings and fasteners. A previous owner had replaced the square top carbs with the round top 1972 version which I rebuilt. The 260 allegedly has the better intake manifold. Add headers, an MN47 mildly ported head (giving me about 10:1 CR), a lighter flywheel from the same donor Maxima, and a reground 270 degree cam from Delta in Tacoma, and that should be a pretty fun street engine in a 2400 lb car. Plus I would not have to worry about whether I should be upgrading to a beefier differential and half axles, triangular front strut bar, cage, and baddog frame rails due to the much higher torque (probably well north of 300) of the SBC. So in the end, I saved the SBC for another project, and went with the straight six. No regrets. Although my next project might well be putting that SBC into a 1978 280z.