tube80z Posted September 24, 2008 Share Posted September 24, 2008 Oops, forgot about the weight differences between SM and SM2. A SR20 swapped 240Z fully prepped to SM2 should come in between 2,050 and 2,150 lbs. You'll have to ballast up to the minimum weight, which isn't too bad a thing. If you read some of the latest news coming from the SCCA they are allowing 200 pounds off the min weight by sticking with 275 or smaller tires. One of the issues I'd see trying to do SM2 in the Z is 18s are going to raise the car. And to take advantage of the narrow track I'd think you'd want to do all you can to lower the CG. SM2 cars are really fast from the results I saw from nationals. But I'd look at CSP for some inspiration of what can be done with a lot less power. The problem with a lot of the packages I've seen is they are difficult to drive to the limit. Have you driven a 400 to 500 HP S30 in an autox. It's a lot of fun but to get the last little bit is a real trick. And forget all the fancy shock stuff unless you have a datalogging system and know how to use it. I've seen plenty of Penskes on cars that would have been better off with non-adjustable Bilsteins. In the end there are probably four key things to keep in mind. You need to build the car and you need to remember what makes a car fast, not what everyone else is doing or how much horsepower someone has. You need to be able to drive the car, which means you need to be comfortable and the car needs to be easy to drive. You need to be able to tune the car and ideally this needs to be done to the track and to the conditions. I've been to a number of national tours and I rarely see this being done. And lastly the car needs to be easy to work on. It's probably going to eat a lot of parts to be competitive. I'd vote for XP personally. More room to work on the problem areas. Either way it sounds like a fun project. Cary Quote Link to comment Share on other sites More sharing options...
logr Posted September 25, 2008 Author Share Posted September 25, 2008 The 200lbs less thing. Is that a done deal or still in the works? SM2 only? Where can I see this? Quote Link to comment Share on other sites More sharing options...
tube80z Posted September 25, 2008 Share Posted September 25, 2008 Go the SCCA website and look at the current fasttrack. This is listed under items for the BOD to vote on. It's not a done deal but generally when they get this far it's a pretty good bet. Quote Link to comment Share on other sites More sharing options...
johnc Posted September 25, 2008 Share Posted September 25, 2008 Go the SCCA website and look at the current fasttrack. I talked with Jason Isley two days ago (he's on the SEB) and what's published for Solo2 is completely wrong. Someone took the list of items out for member comment and mis-labeled them as out to the BoD for approval. He's hoping to get a correction published ASAP. Quote Link to comment Share on other sites More sharing options...
tube80z Posted September 25, 2008 Share Posted September 25, 2008 bummer Quote Link to comment Share on other sites More sharing options...
logr Posted September 25, 2008 Author Share Posted September 25, 2008 I didn't find the 200lb thing but I did find something else interesting. Moving 240Z,260Z,280Z AND 280ZX Turbo to the same line for BSP. I believe that means a 240Z turbo would be legal for BSP. What is weird to me is how they keep Z's in BSP and put a 480hp 4 wheel drive(GTR) in ASP. Can a 38 year old car compete with the newest and hottest there is? Quote Link to comment Share on other sites More sharing options...
LS240 Posted November 5, 2008 Share Posted November 5, 2008 The combined weight of the SR, the turbo, the intercooler, and associated plumbing make the SR swap very close to the weight of a NA L6. And you can move the L6 back in the engine compartment and get the weight distribution close to the same as an SR swap. There's a thread here that compares the NA L6 I built for myself with a SR20DET swap I did for a customer. Overall weights were within 10 lbs and the weight distribution was within 1%. The SR swapped car made 100 more hp then my NA L6. That just seems weird. Based on the generally accepted notion that an LS1 swap adds around 30lbs to an S30 Z, and an LS1+T56 combo weighs around 630lbs, logically one would assume that a stock L series and tranny weighs about 600lbs. Can anyone comment on the weight of the stock engine/tranny? Based on just about everything I've ever read though, an SR20, complete with all accessories, manifolds, turbo, intercooler, and related plumbing, weighs around 330lbs. This is the figure I've seen on almost all the SR20-related forums. If that 600lbs stock engine/tranny weight is true, then the SR20 would have to have a 270lbs transmission, which seems highly unlikely. Perhaps a lot of people have been fibbing about the weight gain of an LS1 swap? Since you've actually built one, and you're obviously reputable, I'm inclined to believe you. But like I said, it just goes against all the previous information I've found. Quote Link to comment Share on other sites More sharing options...
johnc Posted November 5, 2008 Share Posted November 5, 2008 What can I say. I've done a couple more SR20 swaps but was only able to weigh one of them and the results were similar to what I posted above. I think what's confusing people is that I generally build race cars so there's a focus on weight savings. If that focus is applied to any S30, the cars can get down to similar weights regardless of the engine/transmission installed. When the weight savings focus is on the SR20 swapped car and not on the other car used in the comparison, then the comparison is useless. Another example is the folks that say the SR20 swap has much better weight distribution then a NA L6. Well, that's not true either if the car with the L6 has its engine moved back in the chassis like the SR20 swapped car. But again, most comparisons are between a SR20 swapped car with the engine moved back and a stock positioned L6 engine. That's not a fair comparison. Quote Link to comment Share on other sites More sharing options...
johnc Posted November 5, 2008 Share Posted November 5, 2008 You also need to check the weight numbers you're using. A dressed L24 comes in at 390 lbs. http://forums.hybridz.org/showthread.php?t=125246 From my own "lifting" the Type B 4 speed weighs around 65 lbs. Quote Link to comment Share on other sites More sharing options...
LS240 Posted November 5, 2008 Share Posted November 5, 2008 Were the two cars you mentioned identical other than engine? If not, that would obviously throw off the comparison. I suppose the only real way to know would be to either weigh both engine and tranny combos with absolutely everything necessary to have them running, and see what you get. Either that, or weigh a stock Z, then swap in an SR20 and weigh that without doing any other mods whatsoever that could affect the weight, other than the swap itself. Edit: Just read that engine weight thread. Thanks for the link and some very good info there. Considering a weight of 390lbs + tranny, the combo weighing very close to an SR20 makes sense, considering the 5 speed weighs around 100lbs. It still doesn't explain the discrepancy of LS1 cars only weighing 30lbs more than stock though. Unless perhaps that weight gain was measured using a 280Z and the L28 is heavier than the L24? It would have to be nearly 150lbs heavier to account for that though. Perhaps that info for LS1 swaps that I've seen has hidden info about other factors that may have skewed the results. Either that or LS1s are just so amazing they bend the laws of physics. I'm interested in empirical data on CA18DET weight. In my previous research, I've found weights quoted from 290-310lbs for a complete engine. That would result in a combo of close to 400lbs, light by any standards. Quote Link to comment Share on other sites More sharing options...
hoov100 Posted November 6, 2008 Share Posted November 6, 2008 john, with all due respect the SR set all the way back is going to loosen that car up alot more and make quite a bit more power when tuned then setting back the the stock l6 and even doing a 3.1 stroker. I'm sorry, but physics and math dont lie, the sr20 weighs alot less and is about half the size of the l6, there is no way that its going to be within 1% its going to be in more like the 30-40% range. but with all due respect john, i have even done the math and the SR20 does have a fairly large advantage over the L6. Quote Link to comment Share on other sites More sharing options...
patrickhove Posted December 9, 2008 Share Posted December 9, 2008 the sr is heavy. lets see this math. im with you johnc. i have a allmost finished my sr swapped 240z and did notice the engines have very close weights. the sr is not light even though youd think it should be. the sr looks better though. If i were to do it again id do l28t. Quote Link to comment Share on other sites More sharing options...
johnc Posted December 9, 2008 Share Posted December 9, 2008 john, with all due respect the SR set all the way back is going to loosen that car up alot more and make quite a bit more power when tuned then setting back the the stock l6 and even doing a 3.1 stroker. I'm sorry, but physics and math dont lie, the sr20 weighs alot less and is about half the size of the l6, there is no way that its going to be within 1% its going to be in more like the 30-40% range. but with all due respect john, i have even done the math and the SR20 does have a fairly large advantage over the L6. I guess I missed this post a while back. I agree that a turbo SR20DET will make more power then a NA L6 and in the examples I cited above Amir's SR20 car made over 100 hp them mine. The SR20DET, including turbo and associated plumbing, does NOT weight a lot less then a NA L6. I've built a few of both and had the cars on corner weighting scales. The 1% number I mentioned above and you quoted was in regards to weight distribution. Typical SR20DET swaps come in at 48 to 47% Front, 52 to 53% Rear. A NA L6 install with the engine moved back in the chassis typically comes in at 49 to 48% Front, 51 to 52% Rear. There's no way on this planet to get a 30 to 40% improvement in weight distribution from a SR20DET swap over a L6 swap assuming both engines are moved back in the chassis and the chassis are similarly modified. That's in the range of 41 to 39% Front and 59 to 61% Rear and is in Porsche 911 territory. Quote Link to comment Share on other sites More sharing options...
logr Posted January 6, 2009 Author Share Posted January 6, 2009 I'm in the middle of this SR swap and I don't see enough clearance between the turbo outlet and the firewall. The shifter is also barely in the original hole and the SR mount will not clear the steering shaft. I have read where the original crossmember just clears the pan. I am not having that luck. It is a 240Z. It looks like the L28 mounts, on the SR, might clear the steering but I need some room for the turbo outlet without cooking the firewall. There are also some brake splitters or sensors right there where cooking looks very promising. What am I missing? I removed the front crossmember and sectioned it to move the steering rack mount part forward 1/2 in. I also removed the back part of it to give another 1/2 in clearance for the oil pan. This now gives me room to not cook the firewall (hopefully) and puts the shifter in a great location. By moving the engine forward, the trans mount is more likely to be pushing straight down on the rear crossmember instead of have a bad leverage on the tunnel mounts. I would have preferred to have the engine back more but don't see how it is possible. Seems like the pan should not be below the crossmember or the pan would be the first thing to hit anything. Any comments are welcome. I am starting on the actual mounts now. Quote Link to comment Share on other sites More sharing options...
logr Posted January 13, 2009 Author Share Posted January 13, 2009 It is in and fits well by moving it forward just a bit and gaining clearance on the crossmember. I now have about 2 inches to the firewall from the turbo outlet. The shifter is well into the original hole. I cut the trans crossmember on both sides of the mount and put a flat bar in the cut to move it back just a bit and welded it all together. Works and looks great. I used all L24 mounts. The fronts are in upside down to bolt onto the SR with one bolt. The Z driveline slips into the SR trans, a plus I didn't expect. I weighed the SR and trans at 320. New crossmember is 9 lbs. No intercooler yet but that might add 20lbs total. The L28 maxed out my scales. I need to split the trans off and retry but my hoist groans when I lift it. Quote Link to comment Share on other sites More sharing options...
logr Posted January 28, 2009 Author Share Posted January 28, 2009 Here is what I ended up for the SR front mount. Here is the SR installed. Quote Link to comment Share on other sites More sharing options...
logr Posted January 30, 2009 Author Share Posted January 30, 2009 Is anybody interested in a complete build how to, while I am doing this. I have run into things that have not been mentioned and there aren't any builds, with an SR,that I could find. I looked in the build section but haven't been able to find things before, so may have just missed them. logr Quote Link to comment Share on other sites More sharing options...
wheelman Posted January 31, 2009 Share Posted January 31, 2009 Lookin good Mike!!! Are you going to leave the engine mount crossmember bolted in or weld it? I'd go ahead and document the build, it's always better to learn from someone else's experiences rather than figure out the same things over and over again. Have you started looking at the electrical stuff yet? What are you planning to do for the fuel system? A fuel cell or sump the stock tank? I ask because I tried to add a sump to my stock tank to prevent starvation of the EFI pump but ended up creating a big rust problem. The tank started shedding rust really badly so I replaced it with a 2001 Camaro tank that has an in tank pump. I ran it down almost to fumes at one auto-x event and never had a starvation problem. Cody experiences starvation in his turbo 240Z all the time. Just some thoughts and things I ran into running an EFI engine in a car designed for carbs. Wheelman Quote Link to comment Share on other sites More sharing options...
Administrators RTz Posted January 31, 2009 Administrators Share Posted January 31, 2009 Is anybody interested in a complete build how to, while I am doing this. I have run into things that have not been mentioned and there aren't any builds, with an SR,that I could find. I looked in the build section but haven't been able to find things before, so may have just missed them. logr This forum is founded on such things. Swap info is welcome and appreciated Quote Link to comment Share on other sites More sharing options...
logr Posted January 31, 2009 Author Share Posted January 31, 2009 Lookin good Mike!!! Are you going to leave the engine mount crossmember bolted in or weld it? I'd go ahead and document the build, it's always better to learn from someone else's experiences rather than figure out the same things over and over again. Have you started looking at the electrical stuff yet? What are you planning to do for the fuel system? A fuel cell or sump the stock tank? I ask because I tried to add a sump to my stock tank to prevent starvation of the EFI pump but ended up creating a big rust problem. The tank started shedding rust really badly so I replaced it with a 2001 Camaro tank that has an in tank pump. I ran it down almost to fumes at one auto-x event and never had a starvation problem. Cody experiences starvation in his turbo 240Z all the time. Just some thoughts and things I ran into running an EFI engine in a car designed for carbs. Wheelman Ken, look in the fuel delivery section on what I did to the fuel system. I hope to bring it down to the winter heat. Quote Link to comment Share on other sites More sharing options...
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