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.
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.
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.
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.
Your full of ****, if my motor didn't blow up making that on powercards then you could make that much safe with a.... **** I don't have anything witty to compare powercard to along the lines of a child with an abacus and barometric pressure sensor.
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?
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; Feb 7, 2014 at 12:20 PM.
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.
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






