SR20DET!!!!

[awd92gsx]

I don't understand the Rb20 swap...it seems like the SR20DET would be a better swap...the engine would be lighter and cheaper to obtain, and would set the weight of the car back farther...or am I missing something??? 215hp isn't that much for an inline 6...

 

As far as the Rb25DET...it seems like a cheaper and just as good swap would be the 7MGTE, which can handle about the same amount of hp, but can be found for alot cheaper...

 

I look forward to seeing the results of the 7MGTE swap that is being done right here at HybridZ.org.

[yo2001]

I think SR20 even with a single turbo, it's too light to keep the car from lifting while going over 100mph. I know even with L6, the stock z without the from airdam and lowering spring the car lift like hell on the interstate about 100-120mph. In contrast, the light SR20 powered would be a great handling car like RX-7. The SR20 is a great motor, but I think it's more suited for a smaller car. IMO. Also, since the SR is sleeved alunium block, would it not hold as much boost as RB with an iron block? Is the SR20 non turbo block high ductile iron sleeve block? If you want a accessible 4 banger why not KA24 with some boost? How about the torque output of SR20DET? Sorry, I'm in kind of skeptic mood.

[fl327]

i agree with the dsm guy, the 7mgte swap is a nice one. im still not into the sr20det into a z body of any year. 215 hp not enough for stock output? the stock 2.8 turbo motor makes 180 at the flywheel, look at the power you can make out of that engine before you have to break the block open. i wouldnt do the rb25 or any rb until it came in a car here, which doesnt look liek it will happen. 7m's are cheap here and plentiful, but hey if youre gonna go with crazy motors from japan, get real crazy. sure an sr20 has some good power, but its for a wittle car. whats up with the 7mgte anyway. if i could i would straight go with a 2jz supra motor, closest to rb werer gonna see that has replaceable parts availability in the states

[Guest Anonymous]

Just wanted to make some observations, as I have put a sr20det into a 240sx coupe and also have 2 z's as well.

 

I think the sr20det would make an awesome combination personally. A 240sx weighs the same if not more then a Z, so saying the engine was made for a tiny car is ridiculous. (240sx to me looks overall bigger then a z)

 

As far as power potential, people are running 350+ hp at the wheels in 240sx here on stock internals, (upgraded turbo, injectors, manifolds). And as far as a sr20 at 300 hp being not able to keep up with an rb20 at 300 hp, doesn't make any sense (could someone explain?) Thats all I can think of right now for some basic observations.

 

If anyone is interested though in info about sr20 stuff, check out www.freshalloy.com and also www.srswap.com for some info.

[fl327]

rb makes that 300hp easier than the sr20det, revs higher and better and will smoke the sr20.

hey do what you want to anycar you please, the sr20det car we did was very quick, but my v8 car made him by the crew lunch, it was stock but we turned him up to 10psi. same thing in a 510- that thing was ferocious, but still enough for fl327, but would have beat my turbo car by a few, but the 240sx would not have-not by a long shot, and thhts with my L-motor. imma gonna stand by my claim, the sr20 is too small for a z unless you need it for a weight advantage in a racing class and it does make great sense as a handling advantage.. on the street

where most of us drive most of the time, hey i have the turbo L car, now its time for somebody to do a sr20det Z car and really shut me up.

[Guest Anonymous]

See what I can do.

 

I am totally cool with any engine swap (sr20det, any rb series is definetely bad ass ill admit, 6 cylinder L's N/A or Turbo, any V8). I personally haven't ridden in/driven a car with over 250+rwhp (my brothers 240 w/sr20det @14psi is probably 230 or more at the wheels), and I think that car is plenty fast. Although, it doesn't seem as fast once you get used to it.

 

I just could not imagine an sr20@10psi in a 510.

 

I basically just wanted to make some comments. Hopefully I will start posting here more often once I get enough cash to start doing swaps.

 

No hard feelings or anything.

[David K]

you guys go ahead and do the rb swap and ill do the sr20. when we both break down and need parts or a new engine, we will see who is on the road quicker.

[randy 77zt]

all horsepower is not the same.if you have a 500 hp dodge viper and a 500 hp sr20det in a 2600 lb car the viper will smoke it out of a stop light by 3 car lengths.why?its called foot pounds of torque.if you arent ready(get caught with your boost not up )your dead.go out and test drive a z06 vette-many times you dont even need to downshift in these cars.for a beeter understanding ride a 125cc 2 stroke dirt bike and then ride a 600cc four stroke dirt bike.i ride a 600 and i weigh 165lbs. iam building a new motor for my 77 z and am wondering if i will like it when i am done.with the stock zxt engine i run in my 77 i can floor it at 1500 rpm in 4th gear and it pulls with no stumble like a v8.best example of violent torque is the darius moble-close to 600.a 4 cylinder will never make that much.

[awd92gsx]

LOL...never say never.

 

Remember when they said 4 cylinders would never run 13's? I do.

 

Remember when they said, "OK, fine..but...they'll never run 12's.."??

I do.

 

Ok, so now we have 4 cylinders that are knocking on the 6 second door...

 

I would personally rather build a KA24 or a 4G64/4G63 hybrid (as outlined in another thread) and have more "6 cylinder" type torque than build either the Rb20 or the Sr20DET (which if I was going to do that I would just swap in a 4G63 since they are cheaper and more available and just as strong, if not stronger - granted, it's not a Nissan engine), but definitely see the advantages of having the smaller lighter Sr20DET over an L28ET in a car that is primarily designed around handling.

 

Unless you've owned a high performance 4 cyl (by high performance I mean at least 300hp) then chances are you're only giving your opinion, not your experience. I've owned a 300hp (around) 1990 Eagle Talon and about a 350hp 1992 GSX (I say about because it's very difficult to dyno an AWD) and would LOVE to drop either engine into my '77 Z in their present form.

 

Sure, I'd lose a little bottom end but the rush of mid range and top end would more than make up for it. By the end of the run I'd have forgotten what I missed on the bottom end...

 

Which is where the 2.4L stroker comes in...then I could have my low end, mid range and my top end (due to the increased amount of torque across the entire rpm range)

[awd92gsx]

Oh yeah...btw...

 

A 500hp SR20DET in a 240Z would bring it's weight down to about 1900 lbs., if not less

 

Now, a 1993 Dodge Viper was listed as having 400hp and ran a 12.9. Respectable. So, let's figure in another 100hp...

 

I'm guessing that'll probably equate to about a...umm...12.4 or so? Let's even go as far to say it will run an 11.9

 

A 1900 lb car with a 500hp 4 cyl. will probably run closer to a 10.9, if not much faster.

[yo2001]

Originally posted by awd92gsx:

A 1900 lb car with a 500hp 4 cyl. will probably run closer to a 10.9, if not much faster.

Or whole alot of wheel spin. 500HP is probably possible from SR but man it'll be a one ridiculous car. lol 12sec at 130mph lol

[Bob_H]

Ok, I can take a lot, but one I can't let pass:

A 500hp SR20DET in a 240Z would bring it's weight down to about 1900 lbs., if not less

Now come on! First, it is a misleading sentence, (or poorly worded), that the hp has anything to do with the weight. Second, even if you are generous, the SR20DET is at best 100 lbs less than the L6. You have to start with a 2000 lb 240Z. John Coffey is having a hell of a time getting his 240 down to 2100 or 2050. His is a stripped out race car with minimal "creature comforts". Most 240's weigh about 2200-2400. So 2100 with the SR motor if you assume my generous offer. Still, not much weight at all, but in reality, I'd bet the SR20 and all its turbo equip/intercooler, etc.. will weigh pretty close to a stock 240Z motor.

Anyways, 1900 lbs is tube frame racer territory.

And I do need to make one comment about power production with a turbo. First, the 4g64/63 hybrid refered to has great power. But didn' you say that was about 20 psi or more for the mid to high 300 hp range? The RB26dett will put that with 11 psi. Now that wasn't one of the original comparisions, but rather the RB20det. Still, what psi is required for the same hp? I really don't know for the rb20det. But the above was a big factor in my deciding to stick with the RB26 vs the 4g64 stroker. You see, I track my car quite often, and part throttle transitions are a little more tricky when you are talking about building boost to 20 psi vs 11 psi. While I would love to be either on or off the throttle, reality dictates on the track that I must have slowly increasing throttle areas, and the less psi to build, the more linear the response as I put my foot down.

Of course, I don't think this enters into this conversation, for noone was talking about tracking their car.

And next:

I think SR20 even with a single turbo, it's too light to keep the car from lifting while going over 100mph. I know even with L6, the stock z without the from airdam and lowering spring the car lift like hell on the interstate about 100-120mph.

Now we must be careful to seperate the real reason this happens. The stock Z body creates over 100 lbs of lift at the front end at 80-100 mph. Putting less weight overall on the front really doesn't change the front lifting. It just makes the car lighter, and thus overall more suceptable to the aerodynamic forces. There are a bunch of issues that play into that, and I don't think we can say a SR swap would make that big of difference.

next:

IMO. Also, since the SR is sleeved alunium block, would it not hold as much boost as RB with an iron block? Is the SR20 non turbo block high ductile iron sleeve block? If you want a accessible 4 banger why not KA24 with some boost? How about the torque output of SR20DET? Sorry, I'm in kind of skeptic mood

We are all in the skeptic mood. But yes, the iron blocked motor will hold more power than a similar aluminum blocked motor. Also, aluminum disapates more heat and thus in an exactly equal situation,(say a chevy v8, one head aluminum, one iron, C.R., etc.. all same), the iron headed motor will produce more power. The reason for using an aluminum head is to allow for higher compression ratios, which makes more power. But if all factors are held constant except the cylinder head material, the iron head will make more power. And the KA24 is just not as well built as the SR20 motors. And I would agree with the eaiser to source parts comment about the SR motor vs the RB motor. If you are going to stick with a 2.0 liter, go with the SR20. If you want anything bigger, go with the RB. Heck, with the right parts, you can directly bolt in a RB25det. Only the gearbox mount will have to be fabbed,(and possibly the body portion of the gearbox mounts).

Enjoy,

Bob

[David K]

Originally posted by Bob H:

You have to start with a 2000 lb 240Z.

ummm, no you dont. why is it that the majority of z guys think that the 240 is a blessing? I would give a 280zx that ran better and faster and outhandled a 240z way more respect because of the difficulty of getting it right and crap that the zx has.

 

240z's are not the answer to everything.

[David K]

Originally posted by Bob H:

You have to start with a 2000 lb 240Z.

ummm, no you dont. why is it that the majority of z guys think that the 240 is a blessing? I would give a 280zx that ran better and faster and outhandled a 240z way more respect because of the difficulty of getting it right and the amount of crap that the zx has.

 

240z's are not the answer to everything. BTW i have been enjoying this thread in a friendly and educational way very much.

[Bob_H]

Hey, no taking my comment out of context!

That comment was in reference to getting a 1900 lb 240z. You sure as heck aren't going to get a 1900 lb zx or a later z.

And I quoth:

A 500hp SR20DET in a 240Z would bring it's weight down to about 1900 lbs., if not less

I was refering directly to that. I in no way said the 240 was the only way to go or that it was the only way to get to 1900 lbs,(but as far as Z's go, it is the only way to get to that weight w/o chopping off the entire front end). My reference to track driving was for ME track driving MY 240Z on the track and the motor reference. Bottom line, I think you misunderstood the sentence.

Would it be eaiser to understand if I said:

You have to start with a 2000 lb 240z to get down to 1900 lbs with the SR20det (italics added to the original sentence).

-Bob

[fl327]

i like the 280zx's, the turbo car is setup for some major power, i have heard the rear suspension is not like the earlier, but im sure it can be modded up pretty easy to handle well. frame is tough, and very comfortable. i cant say ive had 300hp in a 4cyl, but i can already imagine how peaky it would be, the sr20 510 had 200 or so hp, and it flew! my old civic had about 175, it flew! i would punk LT-1 cars up to third in that car, but if they caught me slipping at the launch i was toast because of the high rpm powerband. i just cant get away with smog that easy, as easy as an early body, plus the older body looks more "old school" -and thats the best thing about having some high techish motor that makes forced induction noises, its plain just bad ass, rolling to spots makes you feel like wangan midonite. there are different types of hp, and you know im not going to do an sr or an rb, because of funny parts, i like 2JZ, because supras are here and parts are more available, just expensive. good luck with the sr20, i really still feel its too small, and even smaller in a zx.

[awd92gsx]

Ok...so maybe 1900 was a little light, but, even at 2100lbs it is still 1100 lbs. lighter than a Viper (which was posted as having a 3300lb curb weight).

 

Actually, you don't need to run megaboost to get power. I remember seeing a 700hp 4G63 that was running only 19psi. I also remember seeing a 9 second DSM using a 4G64 bottom end that never shifted above 7k rpm... (check out magnusmotorsports.com for a little more info...although, he wasn't the originator like his site says...but, we won't go there...)

[David K]

Silvia - SR20DET

1998cc EFI DOHC 16-valve 4cyl turbo

Horse Power: 205hp @6000rpm

Torque: 274Nm @4800rpm

RWD 5-speed and computer(ECU)

 

i dont know what some of you meant by an sr20det not having enough TQ?!?!?!. hell thats more than what my 280zx has and my car is nice off the line.

[fl327]

do it then.

[Bob_H]

Alright, don't make me do a reply like I did in the weber cylinder head thread. But you asked for it. I guess some people just don't know what they are talking about.....(stolen from your earlier post)

 

First, know what you are comparing.

Horse Power: 205hp @6000rpm

Torque: 274Nm @4800rpm

RWD 5-speed and computer(ECU)

i dont know what some of you meant by an sr20det not having enough TQ?!?!?!.

Let me take you back to school.

I refer you to this page for the figures for a "stock" 280zx hp and torque ratings:

Z and ZX specs page

Next, I refer you to this page to covert the NM torque to LB-FT torque (for an apples to apples comparison):

Unit Conversion Page

You will notice that 274 nm of torque converts to 202 lb-ft of torque vice the stock rating of the 280zx of 203 lb-ft of torque. So in 100% stock form, the zx turbo motor puts out more torque,(yea, 1 lb-ft), but more importantly, at a much lower rpm of 2800 vice 4800. That says a lot about driveability. If I am mistaken in reading what you wrote, by all means tell me. But the fun stuff was just beginning.

hell thats more than what my 280zx has and my car is nice off the line

You told us absolutely nothing. I know nothing about your car, no specs, no figures, no numbers, so saying it is nice off the line tells us the reader, Nothing.

You are a fan of the SR20det. No problem. Mike is trying to make an informed decision about which motor to put in. You were dead on in your comments about parts availablility. But don't bring in the other comments, for they only degrade the discussion.

And Len168, you aren't helping either. Your discussions don't address the differences in tuning, hp, setup, etc.. of the cars you compared. I'm not going to get into that right now, but will if you want. Bottom line, w/o car weight, gearing, tires, state of tune, turbo setup, boost, etc.., saying a SR20det was beat by a v8, but ran over xx car tells us nothing. There are SR20 motors with 5-600 hp and will stomp nearly everything on the road. And? There are RB motors that will do the same. W/o specifics, it does nothing for us.

And a comparison of RB to SR motors is only really valid with the RB20det vs the SR20det. With identical displacement, there is minimal advantage with the RB motor. You save weight with the SR motor, but likely can rev the RB higher,(stock vs. stock). Both are great motors, and the SR20 is eaiser to get parts for. However, as soon as you start looking at larger displacement motors such as the RB25/26/30, all that goes out the window. You now have more displacement, so a comparision is not fair or valid.

Keep to the facts, and state your opinions as such.

-Bob

(grumpy right now)