How to increase revs, redline....?
Thread Starter
5th Gear Member
Joined: Feb 2007
Posts: 3,456
From: the flatlands
How to increase revs, redline....?
I have always been aggrevated with the 5800 rpm redline in our 2Vs. What would safely increase the limit? Is it the rotating assembly holding us back? unblanced? Or is the valvetrain and springs? If its just the cams and springs, could we swap to some stage II heads cams and springs, and bring the redline up?
3rd Gear Member
Joined: Mar 2007
Posts: 504
From: Where gunshots are more common than birds chirping
RE: How to increase revs, redline....?
I replaced my valvesprings with COMP beehives and when I got my car tuned I listed it as a mod and they moved my rev limiter to 6500. I've run it like that for almost 6000 miles with no problems at all. I broke a clutch and a transmission before I've had any problems with floating the valves. I remember reading in a 99 GT vs Cobra post that the GT's came weaker straight springs which would limit the revs due to valve float. It makes sense to me anyways to limit the revs that much because I've seen a stock (including top end) GT on a dyno go up to 6500 and at that point it was losing power anyways.
If you dont have cams or headwork you really don't gain much by moving the limiter up and you risk bending a valve or windowing a piston top so it really doesn't make much sense to do that all for only ~5 hp.
If you dont have cams or headwork you really don't gain much by moving the limiter up and you risk bending a valve or windowing a piston top so it really doesn't make much sense to do that all for only ~5 hp.
5th Gear Member
Joined: Nov 2006
Posts: 3,569
From: So Cal
RE: How to increase revs, redline....?
Like I just posted in the sister thread to this one and as 35thAnniGT has experienced, valve float must be eliminated. The stock valve spring won't cut it far past 6000 rpms....
6th Gear Member
Joined: May 2006
Posts: 6,448
From: Ohio
RE: How to increase revs, redline....?
A stock 2v stops making power at 5650 rpms. There is no point in raising the rev limiter untill you have P&P heads, cams, intake. A limiting factor of the rpms is also the bottom end. It is not made for high revs and the bearings and wrist pins will call it quits if it is continueiously reved high.
Thread Starter
5th Gear Member
Joined: Feb 2007
Posts: 3,456
From: the flatlands
RE: How to increase revs, redline....?
Well I plan on doing stage II heads and cams/springs, yada yada, so I was wondering if this would increase my redline. I dont want to a cobra swap just yet. Gonna wait til the car is paid off to all that work. An increased redline would give me more speed at my top end. With stock setup 6K rpm, 3.27 gears top of 4th gets me to 140mph, with 4.10 I get to 111MPH, so with a 6800 redline, 3.73 gears would get me 139mph at the top of 4th and with 4.10s I would get to 126MPH, so its like getting a higher gearswap without sacrificing highway race speeds. The reason I wasnt gonna get 4.10s is because of hauling **** on the highways, BUT if I can increase my redline to 6800 Id do just fine with 4.10s on the highway. Just one of those things to get more bang for buck without compromsing as much.
PLUS with stage IIs you increase your powerband, it would be shame to make all that power up top and not be able to use it right?
PLUS with stage IIs you increase your powerband, it would be shame to make all that power up top and not be able to use it right?
6th Gear Member
Joined: Jan 2004
Posts: 12,575
From: United States
RE: How to increase revs, redline....?
ORIGINAL: oxfordgt
A stock 2v stops making power at 5650 rpms. There is no point in raising the rev limiter untill you have P&P heads, cams, intake. A limiting factor of the rpms is also the bottom end. It is not made for high revs and the bearings and wrist pins will call it quits if it is continueiously reved high.
A stock 2v stops making power at 5650 rpms. There is no point in raising the rev limiter untill you have P&P heads, cams, intake. A limiting factor of the rpms is also the bottom end. It is not made for high revs and the bearings and wrist pins will call it quits if it is continueiously reved high.
Becareful running alot of RPM on a FI car 35th... its a dangerous combonation (FI + RPM) espcially in a linear boost centri setup.
5th Gear Member
Joined: May 2007
Posts: 2,795
From: Michigan
RE: How to increase revs, redline....?
ORIGINAL: GhostRider02GT
Well I plan on doing stage II heads and cams/springs, yada yada, so I was wondering if this would increase my redline. I dont want to a cobra swap just yet. Gonna wait til the car is paid off to all that work. An increased redline would give me more speed at my top end. With stock setup 6K rpm, 3.27 gears top of 4th gets me to 140mph, with 4.10 I get to 111MPH, so with a 6800 redline, 3.73 gears would get me 139mph at the top of 4th and with 4.10s I would get to 126MPH, so its like getting a higher gearswap without sacrificing highway race speeds. The reason I wasnt gonna get 4.10s is because of hauling **** on the highways, BUT if I can increase my redline to 6800 Id do just fine with 4.10s on the highway. Just one of those things to get more bang for buck without compromsing as much.
PLUS with stage IIs you increase your powerband, it would be shame to make all that power up top and not be able to use it right?
if you ar not far off from paying the whole car off, i would suggest you just wait and save the money.
i mean if you plan on doing 4v swap why mod this engine? waste of money
Well I plan on doing stage II heads and cams/springs, yada yada, so I was wondering if this would increase my redline. I dont want to a cobra swap just yet. Gonna wait til the car is paid off to all that work. An increased redline would give me more speed at my top end. With stock setup 6K rpm, 3.27 gears top of 4th gets me to 140mph, with 4.10 I get to 111MPH, so with a 6800 redline, 3.73 gears would get me 139mph at the top of 4th and with 4.10s I would get to 126MPH, so its like getting a higher gearswap without sacrificing highway race speeds. The reason I wasnt gonna get 4.10s is because of hauling **** on the highways, BUT if I can increase my redline to 6800 Id do just fine with 4.10s on the highway. Just one of those things to get more bang for buck without compromsing as much.
PLUS with stage IIs you increase your powerband, it would be shame to make all that power up top and not be able to use it right?
if you ar not far off from paying the whole car off, i would suggest you just wait and save the money.
i mean if you plan on doing 4v swap why mod this engine? waste of money
