280zx Rebuild
10-30-2008, 05:26 PM
#1
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280zx Rebuild
So I've wanted to buy a 280zx and do a rebuild for some real power. I either want to get an N/A and do a l28et swap into it, or find one with the turbo motor already in it. This may sound like the dumbest question but hear me out...If i do the rebuild, should i get pistons with the same compression ratio as the turbo motor (7.4:1 i believe?)? I have been wondering why it is below 8:1. I know you should have a low compression for a turbo engine, but i feel like even that is too low for a turbo motor...Most turbo cars i know the specs of have CR's of 8:1 or like 8.5:1. Can someone educate me on why it's so low on the l28et? (BTW, i have turboed my car so I do have a clue). Do the N/A's have the same borg warner t5 transmission as the L28ET? If i do this build, my power goal is going to be around 400whp or so...I'm still reading through the stickied threads for this so bare with me if i sound clueless haha. Thanks for the help guys.
10-30-2008, 05:38 PM
#2
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the lower compression pistons will let you go for more boost, and extend the life of the engine. there have been engines built for high compression and boost, so you could look up some of them. i think it just involves a good bit of extra money.
10-30-2008, 09:46 PM
#4
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When you said that, did you mean with a stock turbo? I am definitely swapping for a larger turbo after reading what luck ppl have had with different ones. As far as the engine, I'm going to fully upgrade the block and head. So far it sounds like the P90 head is the way to go. I know this is going to be a lot of work and it's going to be the toughest thing i've ever done so i know it won't be easy. I've gone through the whole tuning and reliability thing on a smaller scale for my turbo accord so i have an pretty good idea of what to expect...but i know i'll probably have to deal with some unforseen issues along the way. As for the T5, can that be swapped into the N/A as a direct swap? Also, is the T5 the best way to go, or is there another route i should take?
10-30-2008, 09:57 PM
#5
#1... The reason the L28ET has such a low CR is due to a SOHC, and an old school EFI system. Still, the low CR allows for tons of boost.
#2... Yes, the T5 will swap in. FYI: all L-Series motors and trannies can interchange. Some adaptations may be needed for the drive shaft & getting the tranny mount to fit right.
#3... Building a 400hp L28ET isn't necessarily hard, it's just VERY VERY expensive. It will need to be fully studded, MLS headgasket, head / valve work, stand alone fuel management, proper sized turbo & external wastegate, custom cam, forged pistons, bulletproof drivetrain, and some meaty shoes to grip.
#4... If you want 400hp+ model your motor after Jeff P. He's got about $50K sunk into that car. http://www.angelfire.com/extreme/280zxt/
#2... Yes, the T5 will swap in. FYI: all L-Series motors and trannies can interchange. Some adaptations may be needed for the drive shaft & getting the tranny mount to fit right.
#3... Building a 400hp L28ET isn't necessarily hard, it's just VERY VERY expensive. It will need to be fully studded, MLS headgasket, head / valve work, stand alone fuel management, proper sized turbo & external wastegate, custom cam, forged pistons, bulletproof drivetrain, and some meaty shoes to grip.
#4... If you want 400hp+ model your motor after Jeff P. He's got about $50K sunk into that car. http://www.angelfire.com/extreme/280zxt/
10-30-2008, 10:12 PM
#6
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The non-T5 tranny is virtually the same strength as the early 80's era non-World Class T5's that were installed in the 280ZX. The NA tranny is smoother and in my opinion, it has a better 1st and 2nd gear ratio than the T5's.
What year was the Accord you turbo charged? I'm guessing it was a 90's era 4 cylinder? That's probably about a 30 year newer design with all the efficiency improvements and engine management improvements that go along with it.
The L series motor was a 20 year old design in 1982 although Nissan/Datsun improved it throughout it's life, it's still a single cam non-crossflow head design with significant intake flow restriction when using the factory intake manifold.
In a nutshell, you need some good quality head work from someone who actually knows and has a track record with the L series heads, a bigger turbo, matching fuel injectors, a custom high flow intake manifold and modern fuel management.
If you want to know what turbo to use, check this link that will tell you what size turbo you need to make a specific HP goal with a given engine displacement:
http://www.kamikazeracing.org/dl/ZTe...urboMatrix.pdf
See, that wasn't so hard was it...
What year was the Accord you turbo charged? I'm guessing it was a 90's era 4 cylinder? That's probably about a 30 year newer design with all the efficiency improvements and engine management improvements that go along with it.
The L series motor was a 20 year old design in 1982 although Nissan/Datsun improved it throughout it's life, it's still a single cam non-crossflow head design with significant intake flow restriction when using the factory intake manifold.
In a nutshell, you need some good quality head work from someone who actually knows and has a track record with the L series heads, a bigger turbo, matching fuel injectors, a custom high flow intake manifold and modern fuel management.
If you want to know what turbo to use, check this link that will tell you what size turbo you need to make a specific HP goal with a given engine displacement:
http://www.kamikazeracing.org/dl/ZTe...urboMatrix.pdf
See, that wasn't so hard was it...
10-30-2008, 11:11 PM
#7
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Ya i'm trying to find if there are any shops near me that will do the port, polish, etc...I'm guessing i'll have to ship it out to a reputable place. As for the block, I was debating if this was something i wanted to try and build myself because this car would be a side project. I wouldn't need it running immediately so I have plenty of time. I see that Jeff P. is using a gt35r which was the first turbo that came to mind when i thought of my goals. I'm wondering if i should go with the .82 a/r or the 1.06 a/r (i think it's 1.06). But my turbo choice is the last of my worries haha. I have plenty of other obstacles to overcome first. How much boost can the stock block take? I thought for some reason someone said 10psi was maxing it, which i thought was ridiculous since the CR was so low. I must have misread it though. I would imagine this could do 15ish psi roughly. Then again, i'm not sure what the injector rate is stock. I would imagine the ringlands should be fine, as long as the motor aged decently, and the stock rods and pistons were probably made of some decent material.
As for my car, it's a 1996 accord lx with a garrett super 60 with .63a/r on the hot side. http://www.honda-tech.com/zerothread?id=2305470
That's the link if you guys are interested...it may seem kind of amateur to you guys but it was my first real project.
As for my car, it's a 1996 accord lx with a garrett super 60 with .63a/r on the hot side. http://www.honda-tech.com/zerothread?id=2305470
That's the link if you guys are interested...it may seem kind of amateur to you guys but it was my first real project.
10-31-2008, 09:06 AM
#11
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i still havent found a sweet deal like that 
also as far as 10 psi max boost thats just a safety number we throw around when on the stock headgasket and injectors. im sure the stock internals can handle quite a beating if you used the proper head studs and main/rod stud/bolt setup like ARP then an MLS head gasket a re-worked head and proper fuel management you could put down some decent numbers till something internally in the block gave out.
also as far as 10 psi max boost thats just a safety number we throw around when on the stock headgasket and injectors. im sure the stock internals can handle quite a beating if you used the proper head studs and main/rod stud/bolt setup like ARP then an MLS head gasket a re-worked head and proper fuel management you could put down some decent numbers till something internally in the block gave out.
10-31-2008, 10:07 AM
#14
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I live in Westford, MA. I'll see if i can find one in the Boston area that has had experience with datsun heads. Do you guys suggest a P90A? they have hydraulic lifters i found out compared to the other heads, however if i need to replace them, i'm assuming those are going to be hard to come by...
10-31-2008, 05:52 PM
#16
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If you have a P90A, then don't sweat it. When you start floating your valves at 7000 rpm, it'll be the least of your worries as the secondary harmonics in the stock crank shaft and balancer will be a bigger problem.
The stock internals can handle over 20psi of boost on the stock compression ratio.
The limiting factors on the stock system are fuel volume, engine management and intercooling.
I wouldn't send my head to anyone other than either Rebello in California or Sunbelt Performance in Georgia. These two companies have literally 40 years experience working on various L series motors.
Check out: http://www.rebelloracing.com
The stock internals can handle over 20psi of boost on the stock compression ratio.
The limiting factors on the stock system are fuel volume, engine management and intercooling.
I wouldn't send my head to anyone other than either Rebello in California or Sunbelt Performance in Georgia. These two companies have literally 40 years experience working on various L series motors.
Check out: http://www.rebelloracing.com
Last edited by lww; 11-01-2008 at 12:10 PM.
11-01-2008, 08:43 AM
#17
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i clicke on that llink and it took me to a weird site...then i googled it and realized the link for the site you wanted to give me was www.rebelloracing.com. I checked it out and it looks like i'd probably send my stuff out to them. They sound like they know exactly what they're doing.
02-04-2009, 07:12 AM
#19
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[QUOTE=NismoPick]#1... The reason the L28ET has such a low CR is due to a SOHC, and an old school EFI system. Still, the low CR allows for tons of boost.
#2... Building a 400hp L28ET isn't necessarily hard, it's just VERY VERY expensive. It will need to be fully studded, MLS headgasket, head / valve work, stand alone fuel management, proper sized turbo & external wastegate, custom cam, forged pistons, bulletproof drivetrain, and some meaty shoes to grip.
well that's not entirely true! you could do it the redneck way there nismo. set of mustang svo injectors with accompaning fuel rail and FPR, MLS gasket, gasket match the exhaust ports, and a 40 shot of nitrous will do the same thing at about 15lbs of boost.
#2... Building a 400hp L28ET isn't necessarily hard, it's just VERY VERY expensive. It will need to be fully studded, MLS headgasket, head / valve work, stand alone fuel management, proper sized turbo & external wastegate, custom cam, forged pistons, bulletproof drivetrain, and some meaty shoes to grip.
well that's not entirely true! you could do it the redneck way there nismo. set of mustang svo injectors with accompaning fuel rail and FPR, MLS gasket, gasket match the exhaust ports, and a 40 shot of nitrous will do the same thing at about 15lbs of boost.
02-04-2009, 07:20 AM
#20
Originally Posted by xlpbodily
well that's not entirely true! you could do it the redneck way there nismo. set of mustang svo injectors with accompaning fuel rail and FPR, MLS gasket, gasket match the exhaust ports, and a 40 shot of nitrous will do the same thing at about 15lbs of boost.
You just reiterated what I said:
Originally Posted by NismoPick
it's just VERY VERY expensive. It will need to be fully studded, MLS headgasket, head / valve work, stand alone fuel management, proper sized turbo & external wastegate, custom cam, forged pistons, bulletproof drivetrain, and some meaty shoes to grip.
02-04-2009, 09:28 AM
#21
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if your gonna go n/a, for the street 200 is a good number to hit, but i spent 5000 on my engine and prolly just got a little over that at the rear. if you go the turbo route even 8psi on nismopicks car keep up without too much trouble. if i build a street car engine again, its gonna be turbo, i already use 94 octane, so whats the diff. although the racecar is gonna run 12:1 cr, and hopefully hit 300ish hp. not streetable at all. n/a is really fun to drive tho, never waiting for boost or rpm, much nicer grunt feel.
02-15-2009, 08:20 AM
#22
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no what i'm saying is hey you can get a set of injectors out of a junkyard for what about $50 bucks... plus a $200 head gasket maybe around $120 in a fuel rail and there ya go less than $500 in the motor that will freakin smoke a mustang or vette
02-15-2009, 01:18 PM
#23
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un less its a 4 cylinder stang and a POS run down early vette thats only running on 4 or 5 cylinders...
03-02-2009, 11:27 AM
#24
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with 10psi, i'm pretty sure most of the mustangs around here would lose, but then again, there are only a handful of decent mustangs around here. the rest are owned by hotheaded high schoolers who don't know the difference between ohc and pushrod motors.
