250 is possible
11-27-2003 | 07:20 PM
#1
Guest
Posts: n/a
250 is possible
I've been discussing with a datsun specialist (which I won't go into details who) who has apparently been modifing early Zeds (manuals) to achieve 250bhp from a L28e. The mods are basically an aftermarket ECU, bigger injectors, bigger throttle, performancec cam, flat tops and porting of the intake. It is worth noting a lot of the parts remain stock, including the stock exhaust and manifold.
It would be interesting to see the bhp with custom exhaust and custom intake.
It would be interesting to see the bhp with custom exhaust and custom intake.
11-30-2003 | 12:35 AM
#6
The Evil Twin
Joined: Mar 2001
Posts: 9,296
From: Seattle, WA
I'd guess super high compression of maybe 12.5:1 or higher, a long duration cam that offers no torque and is not considered streetable, and a balanced and blueprinted block so they can run up near 8,000 rpm.
11-30-2003 | 04:08 PM
#8
Guest
Posts: n/a
12.5comp is a bit high, more like 10-10.5
On a n42 head, with stock crank/rods/etc and just with flattops you should get around the 10-10.5 area. Depending where you are you may get away with premium petrol, but I had a little shaving done and had to add some octane boost.
I was recommended to go with a Motec ECU, but I don't see why you can't go for something else.
Mild improved cam. No turbo, ie NA.
I would think the key in the setup would be the larger throttle and modern ECU.
I was recommended to go with a Motec ECU, but I don't see why you can't go for something else.
Mild improved cam. No turbo, ie NA.
I would think the key in the setup would be the larger throttle and modern ECU.
12-01-2003 | 10:44 AM
#9
The Evil Twin
Joined: Mar 2001
Posts: 9,296
From: Seattle, WA
Yes, but that setup you mention above is not going to pull 250 crank hp... I really don't think so. Plus if you want over 200hp you'd better not be running and open chambered head with high compression. Even with octain booster, that's not the best design for power at high rpms.
For torque and high end power fairly cheap and streetable, there's still no replacement for displacement. (or a turbo!)
But that's not to say you cant build a pretty fast n/a 2.8L
Now Norm, the guy with the 12.9 sec dual SU 240Z. He has a light weight car, smaller diamter tires and a 3.9 rear. (about 4.11 overall ratio) He runs about 11:1 compression. He raised his compression even higher to about 13:1 and dropped a few thenths off.... then blew something up! He does run an open chambered head that's shaved so far its practically taken on the closed chambered design. (hard to explain)
I'd think for a 250hp 2.8L you'd have to start with a closed chambered P90, shave that thing way down or get custom domed pistons to raise the compression way up. You'll need ported intake/exhaust and the aftermarket ECU would help. The cam will have to be large enough to flow that air and fuel in at high rpms.
I did read and have a picture of a professional road race L28 that was built for max hp and a good torque curve as it is used in professional racing. I don't know many specs on the build, but they claimed approx 270hp and 260 torque from it with a nice midrange. (what exactly that means I don't know) You can see it uses a single throttle body on a log style intake manifold with aftermarket fuel injection. Sump oil pan for holding high rpms for long periods of time. I don't know what the redline on this is. Maybe up near 9 or ten grand...?
You can also see it uses an aftermarket distributor to keep that timing dead on at the high rpms. The stock Nissan unit is just fine for most applications to 6,000 or so as long as its in good shape. They do get sloppy after all these years.
For torque and high end power fairly cheap and streetable, there's still no replacement for displacement. (or a turbo!)
But that's not to say you cant build a pretty fast n/a 2.8L
Now Norm, the guy with the 12.9 sec dual SU 240Z. He has a light weight car, smaller diamter tires and a 3.9 rear. (about 4.11 overall ratio) He runs about 11:1 compression. He raised his compression even higher to about 13:1 and dropped a few thenths off.... then blew something up! He does run an open chambered head that's shaved so far its practically taken on the closed chambered design. (hard to explain)
I'd think for a 250hp 2.8L you'd have to start with a closed chambered P90, shave that thing way down or get custom domed pistons to raise the compression way up. You'll need ported intake/exhaust and the aftermarket ECU would help. The cam will have to be large enough to flow that air and fuel in at high rpms.
I did read and have a picture of a professional road race L28 that was built for max hp and a good torque curve as it is used in professional racing. I don't know many specs on the build, but they claimed approx 270hp and 260 torque from it with a nice midrange. (what exactly that means I don't know) You can see it uses a single throttle body on a log style intake manifold with aftermarket fuel injection. Sump oil pan for holding high rpms for long periods of time. I don't know what the redline on this is. Maybe up near 9 or ten grand...?
You can also see it uses an aftermarket distributor to keep that timing dead on at the high rpms. The stock Nissan unit is just fine for most applications to 6,000 or so as long as its in good shape. They do get sloppy after all these years.
Last edited by Bleach; 12-01-2003 at 10:47 AM.
12-01-2003 | 10:58 AM
#10
The Evil Twin
Joined: Mar 2001
Posts: 9,296
From: Seattle, WA
LoopMaster, I'm not trying to put everything down that people say! Its just that most engines produce less power on a dyno than the owners claim originally. I was in the same boat with my mild buildup of my car.
stock P79/F54 block. (8.8:1 compression) stock cam, intake manifold, ECU ect.
K&N cone filter, smooth induction tube, larger throttle body, headers, 2.5 inch exhaust.
Stock tire size and stock 3.9 rear
I pulled about 145 rear wheel hp and that's basically what the factory says a new engine does when new!
The guy right before me had a 240Z with a 2.8L, mild cam, tripple webers, EI, headers, 2.5 exhaust. He pulled a whopping 200hp! NOT, actually he got 151hp. Most people with tripples claim they've got a 200hp engine.
And then there's the 510 guys who build a pretty fast L20b and think they've got 170hp or so... on the dyno it ends up being about 120-135 hp. :-( Even the new 350Z with 3.5L engine and DOHC and all that new technology actually pulls 240 rear wheel hp.... and we're trying to reach that with less displacement and only 2 valves per cylinder. I'm just saying it hard to do!
If you have more info on any specific L28 build ups that would be great. And maybe a dyno on that engine so we know just what is acchievable with those specs.
stock P79/F54 block. (8.8:1 compression) stock cam, intake manifold, ECU ect.
K&N cone filter, smooth induction tube, larger throttle body, headers, 2.5 inch exhaust.
Stock tire size and stock 3.9 rear
I pulled about 145 rear wheel hp and that's basically what the factory says a new engine does when new!
The guy right before me had a 240Z with a 2.8L, mild cam, tripple webers, EI, headers, 2.5 exhaust. He pulled a whopping 200hp! NOT, actually he got 151hp. Most people with tripples claim they've got a 200hp engine.
And then there's the 510 guys who build a pretty fast L20b and think they've got 170hp or so... on the dyno it ends up being about 120-135 hp. :-( Even the new 350Z with 3.5L engine and DOHC and all that new technology actually pulls 240 rear wheel hp.... and we're trying to reach that with less displacement and only 2 valves per cylinder. I'm just saying it hard to do!
If you have more info on any specific L28 build ups that would be great. And maybe a dyno on that engine so we know just what is acchievable with those specs.
12-07-2003 | 01:45 PM
#11
Guest
Posts: n/a
Bleach, your original setup sounds close to my car except i have the stock throttle body. Was this in your 2+2 dynoed at 145hp? I was wondering if you gutted the CAT and how fast you think your car was 0-60 and 1/4 mile. As my car has had the basic intake exhaust work but I can honestly say that it is definatley a good bit faster compared to quoted factory performance times. Was wondering if your car pulled faster than factory with your 145@the wheels
12-08-2003 | 03:03 PM
#12
The Evil Twin
Joined: Mar 2001
Posts: 9,296
From: Seattle, WA
I've not raced many Z-cars... only one 280zx and I think I was faster... it was on the highway but I have no idea what he had done to his car. Obviously it was not a turbo or I would of been left in the dust!
My 145hp 280ZX does a bit better than other Z's i think on the top rpms due to the intake/ exhaust work. Its really not that much. I had another 280ZX (my wife's) that was all stock except for a 4.11 rear. Same transmission as mine and everything. Her car was very fun. Lots of torque due to the gearing and the small exhaust but that thing felt out of breath above 4,000 rpm. After I caught up, i blew past her car. My car needs work though. its not in the best shape anymore. I'm probably not at 145hp now with my sloppy timing chain
My 145hp 280ZX does a bit better than other Z's i think on the top rpms due to the intake/ exhaust work. Its really not that much. I had another 280ZX (my wife's) that was all stock except for a 4.11 rear. Same transmission as mine and everything. Her car was very fun. Lots of torque due to the gearing and the small exhaust but that thing felt out of breath above 4,000 rpm. After I caught up, i blew past her car. My car needs work though. its not in the best shape anymore. I'm probably not at 145hp now with my sloppy timing chain
