General Miata Chat A place to talk about anything Miata

Every now and then there comes a dyno graph...

Thread Tools
 
Search this Thread
 
Old 02-07-2009, 05:50 PM
  #41  
Senior Member
iTrader: (7)
 
albumleaf's Avatar
 
Join Date: Sep 2007
Posts: 1,151
Total Cats: 92
Default

Originally Posted by mazda/nissan
they could be making more power than they are, but GM doesn't think like most people. The design of the LS1 isn't horrible, but it doesn't match horsepower/liter with motors such as the BMW M60B40. The one advantage it has is its compact size due to it not having overhead cams.
AAHAHAHA HP/L benchracer arguments, bring it on buddy!! Maybe we should get a Need for Speed tournament going on here let me go put lambo doors on my s14 brb
albumleaf is offline  
Old 02-07-2009, 05:50 PM
  #42  
Elite Member
iTrader: (5)
 
Stealth97's Avatar
 
Join Date: Oct 2007
Location: Canton, Ga
Posts: 2,156
Total Cats: 66
Default

one thing is for certain, I will never build another 4 banger motor for the miata... and I will probably never go turbo but I'd love me a LS1. Too bad my stock motor crapped out before these swaps were widely supported, otherwise I would have already done it.

anyone want to buy a build motor with 10k on it?
Stealth97 is offline  
Old 02-07-2009, 08:50 PM
  #43  
Elite Member
iTrader: (1)
 
NA6C-Guy's Avatar
 
Join Date: Feb 2008
Location: Birmingham Alabama
Posts: 7,930
Total Cats: 45
Default

Originally Posted by mazda/nissan
they could be making more power than they are, but GM doesn't think like most people. The design of the LS1 isn't horrible, but it doesn't match horsepower/liter with motors such as the BMW M60B40. The one advantage it has is its compact size due to it not having overhead cams.
Isnt that engine only rated at like 280hp/300tq though? Yes, it is a much smaller engine displacement wise, but for probably less cost (no idea what one of those cost on the used market, and Im sure they arent nearly as easy to come by) you could have an LS1 making anywhere from 300-350hp and 325-375tq, depending on which of the million versions you find. Sure some of the engine design and technology is outdated, but it still works. Why fix it if it isnt broken? Im not a big GM fan, but I have to admit at least they make some pretty good engines.
NA6C-Guy is offline  
Old 02-07-2009, 09:22 PM
  #44  
Elite Member
iTrader: (2)
 
mazda/nissan's Avatar
 
Join Date: Jan 2007
Location: Lexington, SC
Posts: 2,075
Total Cats: 0
Default

Originally Posted by NA6C-Guy
Isnt that engine only rated at like 280hp/300tq though? Yes, it is a much smaller engine displacement wise, but for probably less cost (no idea what one of those cost on the used market, and Im sure they arent nearly as easy to come by) you could have an LS1 making anywhere from 300-350hp and 325-375tq, depending on which of the million versions you find. Sure some of the engine design and technology is outdated, but it still works. Why fix it if it isnt broken? Im not a big GM fan, but I have to admit at least they make some pretty good engines.
I'm not saying that they don't make gobs of power, but it seems that most people kiss one when they go to bed at night. They are a good V8 to put in the miata due to their compact size, but as V8's go they are soso. Also I wouldn't put any of the big BMW motors into the miata, they won't fit.

Albumleaf wtf are you talking about? I am talking about a motor's efficiency, you are talking about dragons humping miatas
mazda/nissan is offline  
Old 02-07-2009, 09:27 PM
  #45  
Elite Member
iTrader: (1)
 
NA6C-Guy's Avatar
 
Join Date: Feb 2008
Location: Birmingham Alabama
Posts: 7,930
Total Cats: 45
Default

I agree there are better V8's out there, for sure. But for the cost, ease of finding them, and the amount of power you get from them, whats not to like? Maybe if I was rich, and was looking for a project to do myself, I would try out a V8 from something newer, maybe a Toyota V8, but seeing as I dont have the time, money, or tools to tackle a big project, I would stick to the LS and a pre-packaged kit that several people sell.
NA6C-Guy is offline  
Old 02-07-2009, 10:18 PM
  #46  
Supporting Vendor
iTrader: (3)
 
ThePass's Avatar
 
Join Date: Jul 2006
Location: San Diego
Posts: 3,303
Total Cats: 1,216
Default

The most tragic and so terribly common thing to see on the few monsters out there that do have the v8s, be it these new LS series swaps or the 302 monsters of the past, is far too little rubber for such an epic power/torque to weight ratio.
I want sooo badly to see someone who has spent what... 10 or 15 grand on the drivetrain willing to do the flares and 9" or 10" wide wheels with real rubber that the car deserves.. such a thing may be out there but I've not seen it.
-Ryan
__________________
Ryan Passey
ThePass is offline  
Old 02-07-2009, 10:26 PM
  #47  
Junior Member
 
arga's Avatar
 
Join Date: Aug 2006
Location: Ridgecrest, Ca
Posts: 306
Total Cats: 0
Default

Specific output doesn't mean **** in the US where we don't tax displacement. Chevy's engineers were not trying to get the best HP/liter, they were trying to get the most hp/mpg and hp/$.

Almost every racing series out there has some limit on displacement so the engines that make more hp within the confines of the rules deserve more respect. It doesn't really hold up in the real world other than bench racing.

BTW, C4's are dirt cheap right now. My dad just got a 91 convertible for $6k. Yes, the interior sucks unbelievably but it's a complete car for half the cost of the swap.
arga is offline  
Old 02-07-2009, 10:47 PM
  #48  
Junior Member
iTrader: (6)
 
StatixNWH's Avatar
 
Join Date: Jun 2008
Location: Tennessee
Posts: 114
Total Cats: 0
Default

LS1 miata would be SIIICK. And as for the gas mileage, my 1999 FRC corvette averaged 31mpg on a 6 hour trip home to Tennessee from Illinois. Cruising around town, I get probably anwhere from 17-20 if I BABY it.
StatixNWH is offline  
Old 02-07-2009, 10:56 PM
  #49  
Elite Member
iTrader: (16)
 
patsmx5's Avatar
 
Join Date: Aug 2007
Location: Houston, TX
Posts: 9,297
Total Cats: 477
Default

Originally Posted by mazda/nissan
let me do ya some math here

Z06 LS7: 505HP/7L=72.14HP/L
E39 M5 S62: 395HP/4.9L=79HP/L

If GM modernized their motors they could see substantial gains with that much displacement.
I wouldn't bUy an AMG engine, not much of a Mercedes guy myself. It is surprising to see how much better the LS7 does HP/L than the LS1 though.
Dude, GM did that because of packaging. Sure a DOHC variant would be sick, but it would only fit in a suburban or Hummer or something. That motor has so much potential. I'm not an expert with LSx motors, but I know they respond VERY WELL to bolt ons. The GM piece is really not that bad. I'm not fond of it's SUHC design, but for what it is, it's really well designed. If I ever put a V8 in anything where I wanted lots of power, LSx is the only motor I'd use.
patsmx5 is offline  
Old 02-07-2009, 11:08 PM
  #50  
Elite Member
iTrader: (2)
 
mazda/nissan's Avatar
 
Join Date: Jan 2007
Location: Lexington, SC
Posts: 2,075
Total Cats: 0
Default

Originally Posted by patsmx5
Dude, GM did that because of packaging. Sure a DOHC variant would be sick, but it would only fit in a suburban or Hummer or something. That motor has so much potential. I'm not an expert with LSx motors, but I know they respond VERY WELL to bolt ons. The GM piece is really not that bad. I'm not fond of it's SUHC design, but for what it is, it's really well designed. If I ever put a V8 in anything where I wanted lots of power, LSx is the only motor I'd use.
yeah the LT and LS series motors really start doing wonders with bolt ons
mazda/nissan is offline  
Old 02-08-2009, 01:57 AM
  #51  
Elite Member
 
DeerHunter's Avatar
 
Join Date: May 2008
Location: Canada
Posts: 1,983
Total Cats: 2,230
Default

Originally Posted by ThePass
The most tragic and so terribly common thing to see on the few monsters out there that do have the v8s, be it these new LS series swaps or the 302 monsters of the past, is far too little rubber for such an epic power/torque to weight ratio.
I want sooo badly to see someone who has spent what... 10 or 15 grand on the drivetrain willing to do the flares and 9" or 10" wide wheels with real rubber that the car deserves.. such a thing may be out there but I've not seen it.
-Ryan
I've never been a big believer in needing wide rubber to put the power down. Your contact patch depends upon two major factors:
1) Vehicle weight (per corner)
2) Tire pressure

Going to a wider tire makes the contact patch wider, but no bigger (tires design can affect this by a few percent either way, but the rule of thumb still stands). In my opinion, traction in a straight line depends upon the tire compound and little else. If you need more contact patch, lower tire pressures (which is what most drag racers do as a matter of course).

Of course, if you want to corner, then a wider tire (and contact patch) is an advantage. My point is that a high-power Miata that weighs within a reasonable amount of a stock car doesn't need Corvette-size rubber to put the power to the ground or to corner with aplomb.
DeerHunter is offline  
Old 02-08-2009, 02:31 AM
  #52  
VladiTuned
iTrader: (76)
 
18psi's Avatar
 
Join Date: Apr 2008
Posts: 35,821
Total Cats: 3,481
Default

I am not a fan of GM or anything, but c'mon guys: the engine is cheap, puts down great power, compact, simple, and responds like a raped ape to bolt ons. What the **** more do you want? Sure go spend shitloads of money on a mercedes, bmw, etc etc and what do you get? barely better performance for 1000 times the price.....Corvette still uses leaf springs, ohv, and all the other "old technology" and still has no problems keeping up with 200k lambo's and ferrari's on the track or street.
18psi is offline  
Old 02-08-2009, 11:26 AM
  #53  
Elite Member
 
JasonC SBB's Avatar
 
Join Date: Jul 2005
Posts: 6,420
Total Cats: 84
Default

Originally Posted by DeerHunter
I've never been a big believer in needing wide rubber to put the power down. Your contact patch depends upon two major factors:
1) Vehicle weight (per corner)
2) Tire pressure

Going to a wider tire makes the contact patch wider, but no bigger (tires design can affect this by a few percent either way, but the rule of thumb still stands).
I thought this over simplified logic was mythbusted already ... On can do simple though experiment, compare a space saving spare at 40 psi vs. a regular tire at 40 psi, jack the car down onto a clean sheet of paper...
JasonC SBB is offline  
Old 02-08-2009, 11:43 AM
  #54  
Elite Member
iTrader: (11)
 
elesjuan's Avatar
 
Join Date: Jun 2007
Location: Overland Park, Kansas
Posts: 5,360
Total Cats: 43
Default

Originally Posted by DeerHunter
I can't believe I'm even getting caught up in this discussion. I didn't want to do a V8 in my Miata (doesn't suit the character of the car, IMO), I don't particularly like Chevy (I'm an import guy) and the previous generation of M5 has always been one of my dream cars.

However, I think people are losing some perspective here. A DOHC engine will always breath better than an OHV one. Twice the number of valves = better flow. Overhead Cams = less friction and more precise valve actuation. It would be crying shame if BMW engineers were not able to extract 11% more power per liter than Chevy. Personally, I would have expected better.

Chevrolet engineers purposely stayed with the OHV design, not because of lack of know-how, limited development budget or adherence to tradition. The simple reason is that this engine is much less tall and will package better. Look at the technology they did incorporate into this engine:
* All-aluminum block with forged crank and main bearing caps
* Dry sump oiling
* Titanium rods and intake valves (good for 7,000 rpm)

This is not a retro motor with archaic technology, by any standard.

I've said it before.... but can't find it.

2 big *** valves > 4 tiny ------y valves.
elesjuan is offline  
Old 02-08-2009, 11:52 AM
  #55  
Elite Member
iTrader: (2)
 
mazda/nissan's Avatar
 
Join Date: Jan 2007
Location: Lexington, SC
Posts: 2,075
Total Cats: 0
Default

Originally Posted by elesjuan
I've said it before.... but can't find it.

2 big *** valves > 4 tiny ------y valves.
prove it
mazda/nissan is offline  
Old 02-08-2009, 12:45 PM
  #56  
Elite Member
iTrader: (16)
 
patsmx5's Avatar
 
Join Date: Aug 2007
Location: Houston, TX
Posts: 9,297
Total Cats: 477
Default

Originally Posted by elesjuan
I've said it before.... but can't find it.

2 big *** valves > 4 tiny ------y valves.
Wrong on so many levels. I won't even go there, but you sir are incorrect.
patsmx5 is offline  
Old 02-08-2009, 01:10 PM
  #57  
Junior Member
iTrader: (1)
 
robino's Avatar
 
Join Date: Jan 2009
Location: south FL
Posts: 215
Total Cats: 0
Default

deerhunter,
i like the sound of your setup.
what would the hp/tq. be without the hydrasquirt?
robino is offline  
Old 02-08-2009, 01:36 PM
  #58  
Elite Member
iTrader: (5)
 
akaryrye's Avatar
 
Join Date: Jul 2006
Location: Central California
Posts: 2,543
Total Cats: 4
Default

Originally Posted by robino
deerhunter,
i like the sound of your setup.
what would the hp/tq. be without the hydrasquirt?
thats what we call a "threadjack" You do know that you can PM the guy right? Although, im pretty sure the answer is "a bit less" since the water injection allows leaner ratios and more timing advance
akaryrye is offline  
Old 02-08-2009, 02:08 PM
  #59  
Elite Member
iTrader: (15)
 
ZX-Tex's Avatar
 
Join Date: Dec 2007
Location: San Antonio, Texas
Posts: 4,847
Total Cats: 27
Default

Originally Posted by patsmx5
Wrong on so many levels. I won't even go there, but you sir are incorrect.
Agreed, way wrong. The highest specific output piston gasoline engines (NA or FI) are multivalve engines. There are lots of examples of this.
ZX-Tex is offline  
Old 02-08-2009, 02:12 PM
  #60  
Elite Member
 
DeerHunter's Avatar
 
Join Date: May 2008
Location: Canada
Posts: 1,983
Total Cats: 2,230
Default

Originally Posted by JasonC SBB
I thought this over simplified logic was mythbusted already ... On can do simple though experiment, compare a space saving spare at 40 psi vs. a regular tire at 40 psi, jack the car down onto a clean sheet of paper...
Perhaps it has and I'm certainly open to new data if it's presented in a compelling way. I don't think, however, that comparing a space saver to a regular tire holds water. A space saver is generally made from a very durable (read: hard) compound and runs very high tire pressures (60 psi or so) so that it doesn't disintegrate when used. If the pressures are equalized, as you suggest, the limiting factor is the rubber compound. Hard will have less traction than soft.

Look at a top fuel dragster. It's rear tires are not exceptionally wide compared to the power it has to put down (certainly not 12 times wider than a Z06, for instance). It gets traction from a VERY sticky compound and low tire pressures (which gives a bigger footprint). Also consider that as it accelerates, the tire grows due to centripetal force, which has the effect of changing the shape of the contact patch (becomes less wide) without changing the total size (which depends on vehicle weight and tire pressure). Even as the shape of the contact patch changes, traction doesn't alter appreciably (discounting the effect of weight transfer on vehicle weight per corner).

In any case, I'm running 205-50R15 tires (Hankook RS2s), contrary to all kinds of advice to go much wider. While full-throttle in first gear is not advisable, I have pretty good traction in second and beyond. Yes, I know that a wider tire will pay dividends when cornering, but I was first worried about straight-ahead traction with the kind of power I'm running.
DeerHunter is offline  


Quick Reply: Every now and then there comes a dyno graph...



All times are GMT -4. The time now is 03:56 PM.