Seems like a car this light with all that power is screaming for taller gears. Maybe not for autocrossing, but on the street? Any experience?
Visit our community sponsor
Seems like a car this light with all that power is screaming for taller gears. Maybe not for autocrossing, but on the street? Any experience?
No experience yet but I already know I will change a couple of my gears, at least 1st-2nd.
When I did that on my Corrado (was all 6 gears back then) it made ALL the difference with the turbo. I can just imagine the same would apply on the 818, especially cuz it's lighter.
Frank
818 chassis #181 powered by a '93 VW VR6 Turbo GT3582R
Go-karted Aug 5, 2016 - Then May 19+21, 2017
Tracked May 27/July 26, 2017
Build time before being driveable on Sep 27, 2019: over 6000h
Build Completed Winter 2021
I have different 1-4 gears and a 25.5 rear tire size on my 818 C. I have had little street time since I'm now working on the body. I live in country so I did unwind it once or twice before starting in the body. I dyno'd 411 hp and 418 tq to the tires.
315/30-18 rear tire
1st 44 mph at 6700
2nd 75 mph at 6700
3rd 104 mph at 6700
I can't remember 4/5 without looking in my build file. So far seems to perform well, anxious to finish the body and put some real miles on it.
I'm planning on the following (with over 400wtq/whp):
All at 7k in MPH
1st 56-60
2nd 88
3rd 109
4th 136
5th 173
I had the following on my Corrado at 7k
1st 53
2nd 80
3rd 100
4th 125
5th 150
6th 170
Both 5th-6th are theoritical speeds as I'm not sure with aerodynamics they are achieveable.
Frank
818 chassis #181 powered by a '93 VW VR6 Turbo GT3582R
Go-karted Aug 5, 2016 - Then May 19+21, 2017
Tracked May 27/July 26, 2017
Build time before being driveable on Sep 27, 2019: over 6000h
Build Completed Winter 2021
Oh man, don't know how I missed this. I am REALLY interested in what this would entail. On my turbo dodge, I had a taller final drive from newer cars popped into my older transmission and really put legs on all the gears. It was also a relatively light car (2500). Dodge never actually put a 2.5 in it because they thought it was TOO light. But that transmission alone cut .6 off my first 1/8 mile, and a little over a full second on the 1/4 mile drag. It also got me 27mpg driving to work.
How are you planning on changing the gearing? Are the gears easy enough to come by in production transmissions? Custom parts?
Frank
818 chassis #181 powered by a '93 VW VR6 Turbo GT3582R
Go-karted Aug 5, 2016 - Then May 19+21, 2017
Tracked May 27/July 26, 2017
Build time before being driveable on Sep 27, 2019: over 6000h
Build Completed Winter 2021
Right. Something for the Subaru transmissions.
My close-ratio six-speed with 24.85 dia. wheel at 7600 RPM is 171 MPH. I think... 135 in fifth.
My tranny specs are as below. I believe "T.R." (sometimes noted as T.G.) means transfer gear ratio. Most are "1.00". My tranny's 1.1 ratio is to have certain models have the rear diff gear ratio match with the front diff ratio. I'm thinking it doesn't figure into the calculations (because the front diff ratio must match the rear diff final ratio, which would make it a 3.9 ring and pinion front diff. Right?
1ST 2ND 3RD 4TH 5TH 6TH REV. T.R. F.D.
3.636 2.375 1.761 1.346 1.062 0.842 3.545 1.100 3.900
With a 5MT you could have a 3.9 final drive and .738 fifth gear which would give you a laughable 195 MPH theoretical top speed. .95 fourth=151 MPH.
With the .825 fifth gear and 3.7 final drive ratio you would get 185 MPH. 1.151 fourth gear =132 MPH in fourth.
Source: http://www.rs25.com/forums/f8/t10004...ts-ratios.html
For the track would you want to shift less or more, given the typical Subaru motor and limited RPM's? Most tracks I'm on are 1.5 mile on average and no really long, fast straights. I guess a big, wide torque band would help the five-speeds which would use second, third and fourth whereas I have used 2~5 and almost never sixth. With my new close-ratio box I think I will use more of a 3~5 gear range and rely on higher RPMs, from the de-stroker motor, for most tracks.
Last edited by Scargo; 11-02-2016 at 11:28 AM.
"Scotty, give me all the TRACTION she's got!" Pictures of what I drive till 818R is finished
Track Car Journal on IWSTI (with build info)
Here's a useful Gear calculator
I have a RA 5mt, and my rear tires are 26" tall.
Last edited by Canadian818; 11-01-2016 at 10:58 PM.
Adam _____ Instagram @PopesProjects____ YouTube Channel
818 SRX - #91
Arrived 01/02/2014
First Start 10/31/2016
First Drive 05/22/2017
Registered 10/25/2019 BRAP818
Last edited by Scargo; 11-02-2016 at 11:09 AM.
"Scotty, give me all the TRACTION she's got!" Pictures of what I drive till 818R is finished
Track Car Journal on IWSTI (with build info)
Here at NCM Motorsports Park using a 04 5 speed I use 3rd-5th (just get into 5th for short time on the front straight using my 260hp tune I haven't run the 285hp tune yet) with a top speed so far of 131mph. (still have work to do on the chassis and feel I can take out some rear wing)
jcpresto,
Holy crap! $5,000+ if you get all that... plus you are making it heavier which negates some of the benefit of the five-speed being lighter than a six. Frankly, I say "race car", meaning I have no issue with the six protruding out the rear and can deal with the weight difference (more weight on the rear wheels=less wing and less drag). I'm thinking a lot of areo can be accomplished on the front and the fuel cell will be forward. More power and balancing weight on the front? I've always been looking at ST2.
"Scotty, give me all the TRACTION she's got!" Pictures of what I drive till 818R is finished
Track Car Journal on IWSTI (with build info)
I purchased the transmission from Wayne ready to go. I went this route as I didn't want the close 6 speed with this lite of a car and was hoping the selection would help spin the tires less violently with as much power as I'm making. Since I have only go-karted it I don't have any great feedback.
I'll be driving this on the street more than the track, but there is a little bitty track not too far from me (can't be more than a mile, looks like less than that). Probably won't see more than 90 very often (if at all). A good cruising ratio for 5th would be nice. Are all the gears/final drives interchangeable between transmission, too?
FYI- The car (818R) starts to struggle with the aero drag after 125mph. I would just run a Legacy GT trans, and not mess with gearing. It's not worth it on the track, and really not worth it for a street car.
Thanks- Chad
818R-SOLD!!!- Go Karted 7/20/14/ Officially raced NASA ST2- 2/28/15
2016 Elan NP01 Prototype Racecar Chassis #20
1969 Porsche 911ST Vintage Race Car
1972 Porsche 911T (#'s matching undergoing nut & bolt resto in my garage)
haha, 125. I'm not sure I've got the stones to go that fast anymore. I did it a couple times on my motorcycle way back when. I was just looking for options here. I've seen a couple references to 1st gear being useless, and I'd rather not push 3000-3500 rpms cruising down the interstate. If it were as simple as "crack this trans open and take the gears" I'd still be interested. If it's "go buy this set for $2000+", well, not so much.
Chad, is the Legacy GT transmission the same size as my '03 WRX 5-speed? My trans has 235,000 miles on it and I was going to put in new bearings, synchros, STI gears, a Quaife and a new cryo-treat ring and pinion. I already have the Quaife but the rest of that stuff will be $2400+ with me doing the installation. If the LGT was a viable option to live with 350 whp I may consider that option.
Getting the gear ratio right in any build is crucial in order to truly enjoy the car once it is finished.
Making sure that your set up works within the operation range of you engine combination must be priority #1.
R.P.M. 2,500 (2,400-6,400 / Operation Range)
Gear Ratio 3.73
Tire Height 26.0
Displacement 383
Gear Ratio & MPH
1st / 2.68 / 19
2nd / 1.80 / 29
3rd / 1.29 / 40
4th / 1.00 / 52
5th / 0.75 / 69
6th / 0.49 / 106
While I know very little about the Subaru platform, other than the basics, I'd still love to build an 818 when the GoDadGo MK-4 is done.
I'm just am not sure if I'm up to tackling that car because finding Subarus, of any model, are tough to locate down here near N.O.L.A.
Last edited by GoDadGo; 11-04-2016 at 08:48 AM.
Essentially the same size and will bolt right in. There are some differences (speedo gear etc) that you would need to swap over to the Legacy GT trans if you change it. It may also have a different final drive ratio (4.11 IIRC). I bought 2 Legacy GT transmissions used. One had 78K miles, the other 90K miles. I threw the 78K mileage one in after installing a Modena TSB diff. I did not replace or change anything else. I never had any issues with it on the track. Also keep in mind I had a detuned race motor, but if tuned, the motor could easily make over 400HP.
When I say its not "Worth it" for gearing, I meant the cost. Gears are stupid expensive. Finding a better geared transmission, or Final Drive is far cheaper. I find the gobs of torque these motors put out, and the weight of the 818's, gearing is not all that important.
Thanks- Chad
818R-SOLD!!!- Go Karted 7/20/14/ Officially raced NASA ST2- 2/28/15
2016 Elan NP01 Prototype Racecar Chassis #20
1969 Porsche 911ST Vintage Race Car
1972 Porsche 911T (#'s matching undergoing nut & bolt resto in my garage)
If a guy wants 350hp, I'm not sure the LGT is going to cut it for long. IMO the only options are 6 speed or ppg gears in the 5mt. It's true that a 6spd swap might be a little cheaper, but you're still starting with used transmission that has no doubt seen some abuse. And the added weight is in the worse location, behind the rear wheels.
5k might seem like a lot to have a bulletproof 5mt, but spend some time reading what the GTM guys are paying and you'll realize that it's a steal.
Adam _____ Instagram @PopesProjects____ YouTube Channel
818 SRX - #91
Arrived 01/02/2014
First Start 10/31/2016
First Drive 05/22/2017
Registered 10/25/2019 BRAP818
I thought I wanted to stick with a 5 speed but when it blows up, I will be going 6. 5 is great for the street but if you plan on tracking it, the closer gears really helps, even in a car as light as the 818. At the last track session I did, I had guys with bone-stock BRZs (except for Ohlin's coilovers) hang with me for a good ways on corner exits. If I took a corner in third, I didn't pass them until mid way through fourth gear.
You also have to consider the weight of the 6 speed. Its alot heavier. Gearing and weight was not worth it for the track. Example of 3.9 FD
Thanks- Chad
818R-SOLD!!!- Go Karted 7/20/14/ Officially raced NASA ST2- 2/28/15
2016 Elan NP01 Prototype Racecar Chassis #20
1969 Porsche 911ST Vintage Race Car
1972 Porsche 911T (#'s matching undergoing nut & bolt resto in my garage)
LGT 5 speed trannys are cheap because a lot of LGT guys swap in the 6 speed, especially for drag racing. If you are doing hard launches you probably need a 6 speed in your 818 too, but if you are tracking/ road racing / street driving the 5 speed should be a better choice.
If you want a LGT 5 speed let me know and I'll watch for them on the LGT forum for you. I'm pretty active on the Legacy forum.
It's easy to add a tranny cooler to a 5 speed too, covered in another thread.
But note, they don't come stock with an LSD. Every once in a awhile one comes up for sale with an LSD already installed.
"Good Judgement comes from Experience. Experience comes from Bad Judgement"
Owner: Colonel Red Racing
eBAy Store: http://stores.ebay.com/colonelredracing
818R ICSCC SPM
Palatov DP4 - ICSCC Sports Racer
This is what I'm talking about.
The very root of my inquiry.
Interesting perspective, and something I'd like to learn more about. I found exactly the opposite in my other light-ish weight car. Big difference was the power band. It was strong at 2500 rpms, beastly at 3200 rpms, lunched at 5000.
What have you seen them sell for?
I won't be drag racing the car, but it might see some autocrosses and track days.
This looks interesting
http://www.ebay.com/itm/MY05-SUBARU-...3D232131986781
I agree with Chad, on track I am not finding the car between gears at least at NCM. The weight of the car and the amount of torque the engine has doesn't require a lot of gear changes to find speed. Plus as stated the additional 85lb is in the wrong place behind the axle.
And if you look real hard there are jdm 5mt's with RA gearing and a factory LSD.
Adam _____ Instagram @PopesProjects____ YouTube Channel
818 SRX - #91
Arrived 01/02/2014
First Start 10/31/2016
First Drive 05/22/2017
Registered 10/25/2019 BRAP818
"And if you look real hard there are jdm 5mt's with RA gearing and a factory LSD."
And yet, don't you still have the weaknesses of the 5MT? I paid $3,084, delivered, for a like new JDM TY856WB7KA close-ratio box and it has the factory STi LSD. You can also buy fifth-sixth close-ratio gear sets for $500.
The added weight of the 6MT is distributed so it's not like all of it hangs off the back-end and you remove part of that anyway. I just think too much is made of the weight difference issue.
"Scotty, give me all the TRACTION she's got!" Pictures of what I drive till 818R is finished
Track Car Journal on IWSTI (with build info)
$700 doesn't seem bad at all. Change that 4.11 for a 3.9 and we might be in business.
Adam _____ Instagram @PopesProjects____ YouTube Channel
818 SRX - #91
Arrived 01/02/2014
First Start 10/31/2016
First Drive 05/22/2017
Registered 10/25/2019 BRAP818
I found and bought a JDM LGT trans with a 4.44 final drive for $700. Gonna swap that out for a cryo-treated 3.9.
Any idea when you'll have it back in the car and on the road? I'd love to hear some feedback on that setup. Exactly what I'm thinking.
I have an 07 gearset with a (now hardened, after shredding the first one) 4.44 FD. I love my short gears. I don't top out 5th on the straights of the few tracks I've been to, and it's nice having the power everywhere. Maybe a 4.11 would be better, but either way I like having shorter than 3.90 gears.
Frank - Build thread
Yeah, it was kind of a tough call, but I liked how the speeds/gears chart numbers looked and I figured that was what my original '03 transmission would have had anyway.
I am sadly nowhere close to roadworthiness status. Probably another year.
I've found that for the street the stock 05 WRX gears are fine. First is a bit short, 2nd will approach 70 and aero should limit speed, not gearing. on the fun back roads all my driving is in 4th gear as the revs are too low in the powerband to have fun. The graphic is based on stock tire dia, my star specs should be a wee bit taller at 25 inches
gear.png
WRX MPH & RPM Calculator
Gear Ratios 1st 2nd 3rd 4th 5th Final
3.454 1.947 1.366 0.972 0.738 3.9
MPH Calculator
MPH 38.66 68.59 97.77 137.39 180.96
RPM 7000
Tire Diameter 25.00
Aspect Ratio 35
Section Width 255
Wheel Diameter 18
Last edited by RM1SepEx; 12-06-2016 at 03:10 PM.
Dan
818S #17 Picked up 8/1/13 First start 11/1/13 Go Kart 3/28/14
I have no clue what you are talking about. Just too cryptic for me. Aero limits speed?
This fits the front of a stock built 818?
"Tire Diameter 25.00
Aspect Ratio 35
Section Width 255
Wheel Diameter 18 "
Didn't you sell your car in March with 17" wheels? You have another car?
"Scotty, give me all the TRACTION she's got!" Pictures of what I drive till 818R is finished
Track Car Journal on IWSTI (with build info)
Scargo, nope, no sale, I'll own J-Lo forever as a toy! I'm running stock 16's now with tire dia 24.8 or so with 225-50-16 in the rear
the front's don't matter re gearing
for each ratio, top speed in each gear is listed with the stock 05 WRX gearing and a 3.9 diff 68 and change in 2nd, just short of 100 in 3rd, almost 140 in 4th
the car is not slippery enough for my engines HP (about 240 to the wheels) to pull 181 MPH at redline in 5th I'm guessing with the CD and cross section of my 818 155 -160 would be max speed
Last edited by RM1SepEx; 12-07-2016 at 04:06 PM.
Dan
818S #17 Picked up 8/1/13 First start 11/1/13 Go Kart 3/28/14
Any thoughts on that tire size? That's what I want to do, since I'm going to drive this a lot and I know that tire size isn't exactly rare.