Oltmann Posted September 29, 2003 Share Posted September 29, 2003 Where do they come up with the JTR sitting back 4" further back than the Scarab? Only reason I am asking is my scarab with a non HEI distributor/ it's a MSD pro billet, sits 3.5" from the fire wall. With the HEI how the heck can you get four inches? From the intro in JTR: "This manual shows how to set the engine back so that the distributor is within an inch of the firewall (compared to the 3-4 inches of most V8 Z's) ... Positioning the engine 4 inches further back than the typical conversion..." So 4"-1"=4". That's how. Quote Link to comment Share on other sites More sharing options...
DavyZ Posted September 29, 2003 Share Posted September 29, 2003 Technically, the weight is still sitting on the motor mounts... Well, yes and no. The weight is on the motor mounts, but the engine in the JTR position is farther back, such that the front of the motor is nearly behind (even with?) the strut towers. Not so with the Scarab set up. Also, getting an engine higher up in the car does not improve handling from a theoretical point of view, from anything I have read...at least not that I'm aware of. Interesting that the two Z cars are really competitive and the Scarab is still "faster". Clearly, this is due to non-identical drivers, engines, and chassis setup. I'm not trying to be snotty, but I am so darn opinionated lol Davy Quote Link to comment Share on other sites More sharing options...
quicker240 Posted October 3, 2003 Share Posted October 3, 2003 After reading all the posts,I tend to agree with several points.In the real world,overall performance numbers are going to be so close that differences could be attributed to sheer driver or equipment variance. i.e.,having autocrossed competitively for MANY years,my runs would vary AND improve over the course of a day,sometimes by several seconds.Maybe the heat of the day,temp of the tires,number of beers the night before,A smidge sooner braking on this turn or that apex,it just goes on and on. The same can be said of dragracing.RPM at launch 2500 or 2600? shift at 6000rpm or 6100rpm? Can anyone control it all closely as to actually compare the differences on 2 setups that are so very close to each other in performance potential? I think not. I applaud the effort very much,but the results will be skewed in the direction of personal preference by all involved.JTR guys will says theirs are better for this reason or that,Scarab guys,the same thing.The bottom line is,both setups have their pluses and minuses,but they are so small as to really be negligable.The only thing you will prove in the end is which car the chosen driver did better in,not which setup is really superior.I would love to be the driver for this test though,nothing compares to thrashing a hot Z around for days on end!! Just my two cents worth,and my opinion is worth what you paid for it! By the way,I love your mag.! Quote Link to comment Share on other sites More sharing options...
Guest publisher Posted October 3, 2003 Share Posted October 3, 2003 that was very well written! You're ruining his image. BTW, Art --- alot is two words. Can't take you anywhere. Eh, eh, eh. Bob Quote Link to comment Share on other sites More sharing options...
pparaska Posted October 6, 2003 Share Posted October 6, 2003 Technically, the weight is still sitting on the motor mounts, Yeah, I know it's a bit out of context, but the issue isn't how the engine is mounted to the Z's stock motor mount perches on the crossmember, but how much weight is actually put on those perches. Using the JTR set back plates moves the center of gravity of the engine/trans 3-4" rearward over the Scarab position, and that moves the center of gravity of the engine trans back that far as well. Quote Link to comment Share on other sites More sharing options...
DavyZ Posted October 6, 2003 Share Posted October 6, 2003 ... Using the JTR set back plates moves the center of gravity of the engine/trans 3-4" rearward over the Scarab position, and that moves the center of gravity of the engine trans back that far as well... Thanks for iterating what I just can't seem to say! Davy Quote Link to comment Share on other sites More sharing options...
Guest probablecauZ Posted September 25, 2004 Share Posted September 25, 2004 Scientific Method.Observation-Question-Hypothesis-Test/Experiments-Data/Conclusion-Theroy. when testing a hypothesis all variables should be constant except the object of the experiments, i.e. the conversion position. i think that the headers should be the same, the shifter, cable opperated and anything else such as the fabrication work for the JTR conversion should have been done for the Scarab test as well, only if you think it would contribute in any way to any differences in results. I plan on going JTR with my conversion when the hole-in-my-wallet of a motor is done but I'm extremely interested. DO IT, DO IT, DO IT!!!!!! Quote Link to comment Share on other sites More sharing options...
Pop N Wood Posted September 25, 2004 Share Posted September 25, 2004 Mike Kelly is modifying a Scarab in two stages: first upgraded suspension then JTR engine set back. http://hybridz.org/nuke/index.php?name=PNphpBB2&file=viewtopic&t=37219 Sounds like the perfect platorm to test the theory. Quote Link to comment Share on other sites More sharing options...
MikeJTR Posted September 26, 2004 Share Posted September 26, 2004 As of the Author of the Z V8 manual, I want to clarify a few things about the purposes of the set-back position. First, I like this site because of the input and feedback. The people on this site are smart, creative, and enthusiastic. I have learned a lot from this site, and I have met a few of the people who post on this site. One of the problems with writing a book, is that sometimes, people think I know more than I know. As I have told MAS280, he knows more about the V8 Z swap than me. I am sure other people on this board know more about the V8 swap than me. The people who know me understand that I am just your average middle aged nobody, who works out of a home, and has a small mail-order business (JTR Publishing/Stealth Conversions). I mention this because the engine swapping business is not nearly as large or profitable as many people think, and what Scarab accomplished in the 1970's was really quite amazing. I published the first edition of the V8 Z book back in Febuary, 1990 -- over 14 years ago. In 1990, I compared the set-back engine position with the Scarab position (which was first done in the mid 1970's). The Scarab kit was (and is) a good kit. The Scarab was designed over 30 years ago, and a lot of things weren't available today, such as the T5 or T56 transmissions, block-hugger headers, inexpensive aluminum radiators, or powerful electric cooling fans. The Scarab kit, with the mounts, custom bellhousing, custom headers, custom radiator, custom fan shroud, etc, was quite a kit. I owned a Scarab around 1986. It was a fun car. My biggest complaint was the car did not have an overdrive transmission. The set-back position came about because I wanted to fit the Camaro T5 overdrive transmission into the car, and I wanted the shifter to come out of the stock shifter hole. That is the primary reason for the design of the motor mounts. I also wanted to run a big engine-driven clutch fan because I didn't trust electric cooling fans in 1990. To hype (or sell) the setback engine position, I mentioned the advantages of keeping the weight distribution close to stock. As some members have correctly pointed out, the 3-4" setback accomplishes no more than moving the battery to the back of the car. In the 1970-1978 Z cars, it is not difficult to move the engine rearward. I am currently working on a V8 manual and mounting kit for the 1979-1983 ZX cars. It is not as easy to move the engine rearward enough in the ZX to make the Camaro T5 shifter come out of the stock shifter hole. In the ZX book, I am trying to more fully explain the purpose of moving the engine rearward. Thanks for the Hybridz website. I hope I explained the primary purpose of the engine set-back: the shifter position! Quote Link to comment Share on other sites More sharing options...
Pop N Wood Posted September 26, 2004 Share Posted September 26, 2004 Mike, that was a pretty interesting response. We talk about you so much, it is funny to put a person behind our talk. I just read Green Eggs and Ham to my 3 year old. As a kid I remember a teacher telling us the book was about trying something before passing judgement yada yada yada. Years later I read an interview with Dr Suess saying that was nonsense. He said the book was to settle a bet with his publisher that he couldn't write a book using less than 50 different words. Sam I am. Quote Link to comment Share on other sites More sharing options...
hanomon Posted September 26, 2004 Share Posted September 26, 2004 Art, What model/year Z is this going to be done with? Has a bit to do with frame-rails. 40-60-80? Quote Link to comment Share on other sites More sharing options...
SportZ2 Posted September 26, 2004 Author Share Posted September 26, 2004 A 77 280Z Quote Link to comment Share on other sites More sharing options...
pparaska Posted September 26, 2004 Share Posted September 26, 2004 MikeJTR, It's funny that in a REALLY long thread we had debating the placement reasons we finally did come up with one really good reason to use the set-back position - to make the T5, Tremec 5spd or T56 shifter come out in the right place! Glad to hear we got it right . However, I still like the idea of moving the battery to the back AND moving the engine/tranny back. It makes the weight distribution very close to 50/50 (my car is 49/51 F/R with me in it). Maybe that's not a good thing though - lots of torque application means initial understeer as the weight shifts rearward. One thing that is a drawback to the set-back (and lower) engine position is that the oil pan is now lower (assuming a stock depth pan is used in both setups) and fully behind the front tires, making smacking the pan on a speed bump easier. I made things a bit better for my Z by using a now-unavailable from GM Corvette oil pan for the 2pc seal block. It's 7" deep versus 7.5". I just ordered a Canton Road Race pan PN 15-240 that's also 7" deep that I'll use on my 406 engine when that goes in. Another is that there's not really a long tube header that works well with the set-back position. The 30's Ford w/ Chevy V8 header is close, but hangs too low for my tastes. Quote Link to comment Share on other sites More sharing options...
Guest bpilati Posted February 11, 2005 Share Posted February 11, 2005 MikeJTR, your mailbox is full. Quote Link to comment Share on other sites More sharing options...
Psykovertible Posted February 11, 2005 Share Posted February 11, 2005 If you ened up coming to Phx AZ I would suggest my father in law as a drag race driver. Not that I think he is better than anyone else on this site neccessarilly.... but he has been drag racing that old school hot rod way for years. THis is one of those guys that street raced for the money to buy mods. I've been to the track with him and he cuts onme hell of a raction time. Also, he is a great mechanic and does all his own fabrication. Also, he is not a pro at Datsuns but he is vaugely familiar with the concept of two popular type setups. Just figured I'd mention it as an option. Quote Link to comment Share on other sites More sharing options...
Mauisnow13 Posted February 10, 2008 Share Posted February 10, 2008 I live in Idaho, so a lot of the parking lots, and back roads, have huge dips, or speedbumps, or severe inclines. The JTR conversion seems to lower the oil pan kinda low. This makes it hard to drive it safely around these places. Especially in a lowered car. If I ever go to V8, I think I'd like to go Scarab. I'd love to see performance stats between the two. I've heard the pros and cons of both, but i think most of that is kind of opinion, at least the stuff I've heard. I think a nice article would be awesome. A good read, and a good reference. Quote Link to comment Share on other sites More sharing options...
deja Posted February 10, 2008 Share Posted February 10, 2008 Having just switched from Scarab to a JTR setback system I will sya clearance is not an issue. The difference is steering is hard to tell but it does seem the JTR is a little bit easier. I even lower my 208Z 2" and so far the oil pan has not been an issue. Quote Link to comment Share on other sites More sharing options...
COZY Z COLE Posted February 10, 2008 Share Posted February 10, 2008 I live in Idaho, so a lot of the parking lots, and back roads, have huge dips, or speedbumps, or severe inclines. The JTR conversion seems to lower the oil pan kinda low.. LOL.... The real issue is if you have sidepipes,an air dam,and your exhaust cofig. as to what is going to hit something first with the conditions you mentioned.... I have to watch this all the time. LARRY Quote Link to comment Share on other sites More sharing options...
29PGC10 Posted February 10, 2008 Share Posted February 10, 2008 I has been three years since second last post. Has the comparision been done? Any results... I have most of the Nissan Sport/Sport Z and do not recal any articles. m Quote Link to comment Share on other sites More sharing options...
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