Max MP62 Power on stock VVT engine
#1
Max MP62 Power on stock VVT engine
I've recently supercharged my VVT engine. Running a megasquirt DIYPNP Soon I'm going to purchase larger injectors and a smaller pulley. (62.5 mm) I have a power goal of 195-205 HP I think the pulley should allow me to make around 10psi which should get me to my power goal. The supercharger is intercooled. I've read that max safe power on a VVT engine is around 220 or so. It then occurred to me that to make 200 wheel horsepower the supercharger will be using quite a percentage of engine power thus requiring the engine itself to produce over 220 hp to achieve 200 whp The car is running a stock engine and I want to maintain engine safety and reliability even at the cost of power. So I suppose my question is this, is 200 whp safe for the engine or should I lower my power goal slightly in the name of safety? Any advice is welcome. Thanks in advance.
#3
I think you'd be fine at 200 whp. As mentioned above, wtq (rear wheel torque) is more of an immediate concern than whp. From what I've gathered, 250 wtq is a threshold for the stock connecting rods. You will undoubtedly be well below that, even if you include the added parasitic load of the SC.
May I suggest that you consider keeping your stock SC nose pulley and looking into the option of using a 150mm crank overlay pulley to increase boost instead. There is a factor of diminishing returns on those smaller pulleys when used with a 4 rib belt (assuming you have one); you're asking for more and more load to be placed upon a smaller surface area. Belt slip becomes fairly imminent when you get up to your intended power levels.
May I suggest that you consider keeping your stock SC nose pulley and looking into the option of using a 150mm crank overlay pulley to increase boost instead. There is a factor of diminishing returns on those smaller pulleys when used with a 4 rib belt (assuming you have one); you're asking for more and more load to be placed upon a smaller surface area. Belt slip becomes fairly imminent when you get up to your intended power levels.
#4
I was really hoping I could just swap the pulley...in order to come up with the same ratio, I'd have to purchase the 200 dollar overlay pulley and still a different supercharger pulley.
I discussed my power goals with Gary at TDR and he seemed to think my power goal was ok with the 4-rib and the pulley swap. I wouldn't mind going to a 6-rib but so far it's been rather unclear to me as to how to do that.
I discussed my power goals with Gary at TDR and he seemed to think my power goal was ok with the 4-rib and the pulley swap. I wouldn't mind going to a 6-rib but so far it's been rather unclear to me as to how to do that.
#5
Hello person with not clue what they are doing.
Stock 02 with mp62, 62mm pulley(11ish psi), 305cc and popopo-powercards got me 190hp.
stock 02 block and trans are good for the 250 range but would not go over that. Having a good smooth tune helps it not brake apart.
I'm putting down 250whp/215ftlb range now on a 99 block, 01 trans with a 65mm pulley (8-9 psi).
Have only used a 4 ribs and stop crank pulley.
Stock 02 with mp62, 62mm pulley(11ish psi), 305cc and popopo-powercards got me 190hp.
stock 02 block and trans are good for the 250 range but would not go over that. Having a good smooth tune helps it not brake apart.
I'm putting down 250whp/215ftlb range now on a 99 block, 01 trans with a 65mm pulley (8-9 psi).
Have only used a 4 ribs and stop crank pulley.
#14
Dang, Jeff, why the hate, bro?
I made a little over 200 whp @ 10 lbs boost, 4 rib belt, stock internals on a powercard as well and never had an issue. Mine nor Jeff's cars are VVT. Don't know if that makes a difference. Now I did grenade a 5 speed transmission at that power. But that coulda just as easily been operator error as I was just learning to drive at the track.
You gonna yell at me too, Jeff?
I made a little over 200 whp @ 10 lbs boost, 4 rib belt, stock internals on a powercard as well and never had an issue. Mine nor Jeff's cars are VVT. Don't know if that makes a difference. Now I did grenade a 5 speed transmission at that power. But that coulda just as easily been operator error as I was just learning to drive at the track.
You gonna yell at me too, Jeff?
#16
C-C-C-C-C-C-C-C-COMBO BREAKER
Yes 200 is probably safe, since if I remember the MP62 data correctly at 200hp its requiring ~30-40 hp from the belt to drive it, so your rods, piston, and crank are experiencing ~240hp, but its only showing up on the dyno as 200.
I think you'd be fine at 200 whp. As mentioned above, wtq (rear wheel torque) is more of an immediate concern than whp. From what I've gathered, 250 wtq is a threshold for the stock connecting rods. You will undoubtedly be well below that, even if you include the added parasitic load of the SC.
Last edited by Leafy; 02-07-2014 at 12:20 PM.
#18
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Get a 6 rib belt, order tensioner 38178 from Dayco, install with proper adapter you can source from Tom or Gary, and do not look back.
200 whp on a stock engine is OK.
DO NOT go for the 150mm pulley. I did, and promptly fuggered up my blower.
200 whp on a stock engine is OK.
DO NOT go for the 150mm pulley. I did, and promptly fuggered up my blower.
#20
I am curious why that overlay pulley messed up your blower though. Were you already running a really small nose pulley when you added it, or what?
The overlay always seemed like the lesser of evils if you were stuck with no auto-tensioner and a 4-rib setup, as you could retain more belt traction by keeping a larger nose pulley in conjunction with the overlay. Do you think that is not so?
Sorry