Modifications for L28E

Answer to most of the common technical questions
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Red eyeZ
Posts: 18
Location: Masterton , Queenstown

Modifications for L28E

Post by Red eyeZ » Thu Jul 23, 2009 11:54 pm

Hi i need some suggestions on some modifications for my L28E . Has been completely stripped and rebuilt and has had a medium spec cam grind .Has also got custom made tune length headers , big bore exhaust and pod filter . Everything else is standard and would like to know what my next steps would be for improving the power . Keeping it NA . Any suggestions ? I heard that the EFI engines were derated in power to improve fuel economy , is this true ? and if so is there any ECU upgrades that will bring it back to its full potential? This car is a long term project and will look into brakes and suspension modifications as well. Help on these topics would be much appreciated thanks.

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nustad
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Posts: 551
Location: Auckland

Post by nustad » Fri Jul 24, 2009 9:42 am

When you say big bore - how big? More than 2.5 or 2 3/4 inch you might be losing power.

Sounds like you have done the easy things - how confident are you with the ignition quality and timing.

Really the next thing is thinking about improving the flow through the head which is a step up in $......

I reckon spending money on suspension will yield more fun per mile.

Cheers

Glenn
72 240z plus bits

Red eyeZ
Posts: 18
Location: Masterton , Queenstown

Post by Red eyeZ » Sat Jul 25, 2009 1:59 pm

would probably go 2 1/2 inch , havent built the exhaust yet only the headers so far . Going to experiment with different combinations of mufflers to get the best possible sound out of it. As for the ignition and timing im not too sure , mechanical side is all good the cam was dialed in properly but the electrical side im not too sure about. As for the suspension , are there kits available for harder shocks , springs , sway bars and bushes ? I want to get larger brakes as well and was going to do them in conjuction with the suspension to avoid any interference , Has any one done these mods and could they post any information please.

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djz
Posts: 849
Location: Christchurch

Post by djz » Sat Jul 25, 2009 7:29 pm

More compression and some head work, or turbo it :) there aren't really any ecu upgrades you can do keeping the stock system, a standalone (Link etc) would be good but I don't think it will gain you very much.

I think you can get kits for the suspension and brakes from the US, here you can buy everything seperately, it depends on how serious you want to get with it. At the moment I'm running HR31 front struts and Cobra springs and KYB shocks front and rear, GTS-t Skyline front brakes with Z31 5 stud hubs and Z31 rear brakes and hubs. Nolathane do most of the bushes, the other bush makers do too.
Nissan 280ZX 2 seater RB26 powered.

Red eyeZ
Posts: 18
Location: Masterton , Queenstown

Post by Red eyeZ » Sat Jul 25, 2009 8:06 pm

Thanks for the replies , how hard is the conversion between stock set up and the set up you have at the moment djz. Is it a simple bolt on or is there some engineering involved. I would be keen to copy your set up rather than getting kits from the us . Do the stock axle shafts fit the z31 rear hubs or do you have to replace those as well? Could i get part numbers from you if possible ?

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djz
Posts: 849
Location: Christchurch

Post by djz » Sat Jul 25, 2009 8:30 pm

It's not exactly bolt on but it wasn't too complicated, trying to find some of the bits can be difficult and the way I have it set up the offset between the front and rear is quite different so I have to run spacers on the back.

For the front the spring perches have to be cut off the HR31 struts and the Z one welded on or go with a coilover setup. The Z32/R32 calipers bolt straight up, I'm using AU Ford Falcon (I know, it's terrible) rotors, the hubs were slightly modified so that the rotors bolt to the front of them instead of the back and I had to run longer studs - the Z31 studs are really short for some reason.

For the back I'm using late S130 calipers with Z31 caliper brackets, I think the Z31 calipers would work too but the pair I had were trashed, there might have been something funny with the handbrake too. The Z31 rotors had to be turned down slightly to clear the inside of the caliper and the caliper spaced out 5 or 6mm. The wheel bearings had to be changed to Z31 ones and I had to buy new bearing spacers, the stub axles and companion flanges fit up fine.

I think the stock early half shafts will bolt up to the Z31 stub axles, my car has/had a late S130 CV rear end so the stub axle flanges had 3 sets of 2 bolts where I think the early axles and the Z31 axles have 4 single bolts, I'm using the Z31 CV axles as they are stronger.

Sorry for filling up your engine thread with suspension stuff. If you have any other questions or want some more pictures I can do that when I get back home later this week.

Image
Image
Nissan 280ZX 2 seater RB26 powered.

Red eyeZ
Posts: 18
Location: Masterton , Queenstown

Post by Red eyeZ » Sun Jul 26, 2009 1:42 am

I have already purchased 17inch rims for the stock 4 stud hubs , is it necessary to change them to z31 five stud hubs?

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djz
Posts: 849
Location: Christchurch

Post by djz » Sun Jul 26, 2009 10:56 am

Not really, I was running the HR31 brakes on the front for a while, I always intended to go to five stud so I never really looked into putting bigger brakes on the four stud hubs. I'm not sure whether the length of the front hubs is the same, I have a feeling they won't be as the HR31 brakes have slip on rotors and the Z31 hubs use bolt on rotors.

Have a look at http://www.arizonazcar.com/510brakes.html
Nissan 280ZX 2 seater RB26 powered.

Red eyeZ
Posts: 18
Location: Masterton , Queenstown

Post by Red eyeZ » Sun Jul 26, 2009 2:49 pm

thanks for the link , they look pretty good . I wont be touching the brakes till next year just got to focus on getting the engine running mint for now but thanks for all the info. Might have to get a second job i think
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BRONZEE
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Posts: 7200
Location: Auckland

Post by BRONZEE » Sun Jul 26, 2009 7:30 pm

Sorry very off topic, but DJ when did you put those Z33 shoes on your 280????

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djz
Posts: 849
Location: Christchurch

Post by djz » Sun Jul 26, 2009 10:03 pm

That's a good looking Z, are you using spacers for those wheels? It looks pretty low, what suspension have you got at the moment?

I had the 350Z 18"s on my car a while ago, to be honest it drove terribly with them on and it looked like a rollerskate so I went back to the 17"s.
Nissan 280ZX 2 seater RB26 powered.

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Baker93
Z Club Member
Posts: 331
Location: Auckland

Post by Baker93 » Mon Jul 27, 2009 8:20 am

Hi Firstly i am not a 280Z expert, but the next step you need to take for improved performance as with any Z is its breathing ie increased air flow both in and out of the engine then you need to burn it. Firstly over the years many members have tried making L series motors go hard on standard fuel injection. They dont/wont so stop now and have a good think about what you want to achieve long term before throwing money at it. Basically have a look at the size of the inlet runners etc and compare them to a manifold from a set of triple carbs and you will start to get the idea. Secondly the factory electronic ignition is junk they tend to back down or retard excessively at highish RPM (over 5000) and as a bonus do not provide a good spark. If this is a long term project think seriouly about good quality after market engine management (fuel & ignition) coupled to throttle bodies and a decent manifold. The difference good breathing and ignition makes to an L series motor is staggering and this is before head work. My race car has very little head work ie port matching, deburring a 10.5 to 1 compression good but not fantastic ignition and big carbs. If you have seen it im sure you would agree it never been accused of not making good power or revving. Exhausts - mixed use car a 2.5 will be just fine big revs or more serious top end use get a 3.0 i have used both. 2.75inch pipe seems impossible to get in this country. Contact me if you need any more conflicting information.

kiwi303
Posts: 260
Location: SalmonTown

Post by kiwi303 » Mon Jul 27, 2009 3:30 pm

Baker93 wrote: 2.75inch pipe seems impossible to get in this country.
correction: Impossible to get at a muffler shop. Dairy shed outfitters carry stainless 2.75" and all the bends you would ever need.

Red eyeZ
Posts: 18
Location: Masterton , Queenstown

Post by Red eyeZ » Mon Jul 27, 2009 8:26 pm

iv got 5mm spacers on the front and rear , tyres come close to the struts on the front . Far as i know the suspension is standard . The chassis has been reinforced and is even closer to the ground , roughly about 100 mm . Those are performance wheels , integra i think they are called , 17x7 with 215/40 R17 Eagle F1 tyres on them , I think the diameter is slightly smaller than the standard wheels . The paint job is Massey Fergusson red , not my choice in colour thinking about either skyline blue or a gloss/semi-gloss black.

Red eyeZ
Posts: 18
Location: Masterton , Queenstown

Post by Red eyeZ » Mon Jul 27, 2009 8:50 pm

Thanks for the info baker , i dont think il spend big bucks on the engine , done most the work myself . Im satisfied with what i have done so far just thought it would be a good idea to ask for some advice while im still working on it thats all . carbs would sound heaps better than injected though .

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