Bought a Volvo V50, now I feel like my Miata is slow
The volvo has a 2.5L 5-cylinder turbo making an unknown-to-me amount of boost.
It's rated at around 230hp and 235 lb-ft of torque. The power to weight ratio is probably similar between my two cars but the volvo has full torque at like 1500 rpm. After driving the volvo for a few days in a row, switching to the miata feels disappointing (at least in regards to acceleration). In the Volvo a quick jab at the throttle at low RPMs creates a satisfying lurch forwards. The miata, in comparison, feels sluggish until it opens up around 3500 / 4000 rpm. SO, to all the owners of fast miatas, what are your tips for generating more juice down low? Is a 3" exhaust a good bet, or do you reallly just need more displacement for good low end torque? |
What turbo are you running? What exhaust? At 10psi you must be maxing out those 305's. Tune? Timing?
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Should be hitting the limit of 305's at around 8psi, definitely 10 without a fuel pressure riser. What are your air/fuel ratios?
Smaller turbos are the cure if you want more power down low, but obviously you'll be sacrificing your top end powah a bit. I'm running into that problem in my Greddy setup. Great power starting as low as 2000rpm, but once it hits full boost at 4000, it just sits there at the same power/acceleration until redline. Still fast though. |
damnit, i wrote a whole reply and lost it.. here it goes again :)
I have a begi-s with gt2554 turbo. Kept the FPR with the 305s, can hit 10.0 AFR under full boost. Fuel & Timing is tuned on the street, no dyno time.. local guy quoted me "125 for three pulls". I don't knwo if that's enough time to really do anything so i haven't gone yet :) Current timing map attached, maybe that's part of it? Oh -- my exhaust is a 2.25" stainless steel "made in china" deal w/glasspack exhaust. the cat is by magnaflow. -Tomaj |
More boost, bigger exhaust, tune. :)
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(just realized i forgot to attach timing map -- will get it in a minute!!)
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no offense, but if you think your volvo is fast enough to make the miata seem slow your miata must be SLOW AS BALLS
Generating more torque down low can to a certain point be done by retuning timing down low. opening up the breathing also helps.......or you could just get a tiny ass turbo (like the one on the volvo) and gain a shit ton of lowend/midrange at the expense of your topend |
He already has a 2554, can't go much smaller than that, really.
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@18psi -- LOL no offense taken.
That's the other thing.. i've never driven a 'fast' turbo miata so i'm not sure what exactly it should feel like when set up right. Maybe i should just bite the bullet and do a dyno run just so i know where i stand, maybe that'll give more information on what to do next/ |
I'd guess around 170-180.
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Originally Posted by kotomile
(Post 554152)
He already has a 2554, can't go much smaller than that, really.
Its nice to have lowend torque on a daily driver, I know EXACTLY how OP feels. |
Semantics, sir. There are smaller turbos, but as you said, they would be complete fail on a Miata.
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Low end torque in a 1.6L Miata costs money, how much do you want to spend??
A 2L FE3 with custom turbo manifold and BB 2560 would pull like a freight train. The same turbo on a 1.8 BP would also have good low end. If you want 8-10 psi boost by 2,200 RPM (and don't want to run more than 10psi), put on an Aerodyne or Aerocharger VATN turbo (don't expect it to last as long as a Garret) If you want the best of both worlds with a 1.6L, run a compound setup with T28 sleeve turbo blowing into a supercharger. |
Using an RRFPR with a fully tunable ECU introduces a variable that isn't needed. Sell the RRFPR and the 305's and get some RX7 550's and dial in your tune. At 10psi with the 2554r and a 2.25" exhaust, I'd say 180-190whp is about right... but you'll never know without a dyno. I don't think you'll see a huge WHP jump by switching to a 3" exhaust, but you'll see a big torque increase and probably see full boost a full 500rpm quicker. Besides a tune with bigger injectors, a bigger exhaust is what you need.
How are you tuning timing? What map are you using? $125 for 3 pulls is a crock of shit. That's what all the Socal AWD dyno guy get because there are so few of them and they'e alway full. But a simple 2wd dyno on a mid weekday should be $50 for a set of baseline pulls or I'll just do without. |
samnavy, i hear you regarding the extra variable of the FPR... I"ll keep an eye out for a set of injectors and once i get them i'll do the swap and pull out the FPR... Know anyone who wants one? :)
I'm not really tuning my timing.. I'm sure i'll get flamed here but i just look at what everyone else is running and try to pick what seem like safe numbers.. Way back before i got my IC and megasquirt i used to get knock, so i know what it sounds like (i know there's various kinds, even inaudible).. i haven't heard anything remotely like it and i don't drive that crazy so i figure i'll be OK for now. @sn95 - i've read enough horror stories to not consider the aerodyne.. sounds like really neat technology but i don't want the headaches. Eventually if my engine ever dies i'll consider getting a 2L if my budget permits, or at least definitely a 1.8L. |
Originally Posted by sn95
(Post 554223)
If you want the best of both worlds with a 1.6L, run a compound setup with T28 sleeve turbo blowing into a supercharger.
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Originally Posted by Pusha
(Post 554242)
Do you have a link to where this has been done on a 1.6?
To the OP i suggest more timeing and more boost. A properly tuned WI system will help you with both. |
10:1 AFR isn't helping you out.
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1 Attachment(s)
jayc72 -- you're right that 10:1 is too rich, i'm just trying to make the point that I *can* hit that number.
My targets are as 11.8 @ 170kpa, 12.0 @ 150kpa, 12.8 @ 130kpa, 14.2 @ 110 kpa 14.7 @ 100 kpa-30kpa How do you like your enthuza 3" exhaust? Did you get the regular or budget model? -Tomaj P.S. timing map is finally here :) |
Originally Posted by magnamx-5
(Post 554247)
sure if you search on m.net you will see the twincharge lunacy totally unnecessary, and overcomplicate imo.
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