2.57 pulley with 10% overdrive on a M90?

[snopro442]

would like to know if anyone is running this set-up? I have the m90 with the roush power pulley on the snout and the stock lower pulley. I would like to know if its worth installing the 10% overdrive with the 2.57 upper pulley. I already have the larger heat exchanger and the gt500 fuel pump installed, any info would be great Thanks

 

[Mustang30212]

I have this setup. When I installed the 10% pulley I did not pick up ANY horsepower. It did bring the boost in a little sooner giving me a little more seat of the pants feel...but I believe the extra heat generated by overspinning the blower actually hurt performance in day-to-day driving.

If I had it to do over again...I wouldn't do it.

Now the 2.57 pulley alone IS worth the effort.

RH

 

[skwerl]

Heat is your enemy with this setup. I'm dreading the return of summer. You need to watch your intake air temps closely. A lot of stop and go driving will shoot them through the roof in no time, as will a few hard pulls.

I'm also looking for more power but with less heat. For the last year I've been looking at ways of addressing the heat issue before pushing the power any higher and I finally found a solution that does both. VMP is currently in the production phase of a new TVS1900 supercharger that will bolt directly to our intakes. Not only will this increase our boost capabilities but the TVS1900 is just about the most efficient twin screw blower on the market. Head unit temps will run about 100 degrees cooler at 8 lbs boost. Also, the M90 takes 70hp to spin it hard enough to make 8 lbs boost, the TVS takes 28hp to generate the same boost.

So even keeping the boost to 8 lbs, I pick up 48hp and my intake temps drop dramatically. I will also have the ability to up the boost to as high as 15 lbs once I forge the motor. Yes, it costs $3600. But how much will you spend trying to deal with the heat issues overspinning the M90?

The TVS1900 head units will be available in a couple months. You can preorder on the VMP website with an $800 deposit.

 

[JimIII@JDM]

We run this combination often and though the 10% OD does add more heat that can be combated with a bigger heat exchanger. The 10% pulley doesn't add a whole lot of HP but we have seen gains of 25 lb/ft of TQ which you will feel seat of the pants. Like mentioned above it brings the boost in quicker so its more responsive too. We have seen 10 RWHP from these, so it does help some. You might want to make sure to check your injector duty cycle as we have seen the stock Roush injectors max out or come close with this combination. Depends on how much power you make.

 

[snopro442]

I have the Afco heat exchanger installed, its for the gt500. I also have the injectors that came with the m90. The car will be driven mainly on the street and a few times down the local strip.

 

[AutoXRacer]

I have the Afco heat exchanger installed, its for the gt500. I also have the injectors that came with the m90. The car will be driven mainly on the street and a few times down the local strip.

When I had the M90 setup, I ran it with a 2.57" snout pulley and a ROUSH 12% over-drive crank.

I went from 435rwhp/415rwtq to 440rwhp/450rwtq!!!
I never had any heat issues...yes my IATs were hot when hot lapping at the drag strip and in traffic, but cooled off instantly as soon as you start moving.

I say do it!!! You'll love it.

I did later go further and install a 2.49" snout pulley. I don't think this was worth it as the throttle response became like a switch. Instant wheel spin in 1st and 2nd. I had to recalibrate my foot. LOL Peak boost hit around 11PSI cooler winter air almost peaked at 12PSI. What a rush with the super whine of the blower!!

I say the best combo is the 2.57" + the 12% OD crank.
I did have to upgrade to the GT500 fuel pumps though...or at least you can do a BAP. You may be able to get away with just a FPDM wiring mod.

 

[Captainstr8edge]

Heat is your enemy with this setup. I'm dreading the return of summer. You need to watch your intake air temps closely. A lot of stop and go driving will shoot them through the roof in no time, as will a few hard pulls.

I'm also looking for more power but with less heat. For the last year I've been looking at ways of addressing the heat issue before pushing the power any higher and I finally found a solution that does both. VMP is currently in the production phase of a new TVS1900 supercharger that will bolt directly to our intakes. Not only will this increase our boost capabilities but the TVS1900 is just about the most efficient twin screw blower on the market. Head unit temps will run about 100 degrees cooler at 8 lbs boost. Also, the M90 takes 70hp to spin it hard enough to make 8 lbs boost, the TVS takes 28hp to generate the same boost.

So even keeping the boost to 8 lbs, I pick up 48hp and my intake temps drop dramatically. I will also have the ability to up the boost to as high as 15 lbs once I forge the motor. Yes, it costs $3600. But how much will you spend trying to deal with the heat issues overspinning the M90?

The TVS1900 head units will be available in a couple months. You can preorder on the VMP website with an $800 deposit.

I didn't realize they were taking pre-orders. That makes me happy. I won't be getting it anytime soon but its good to know the option is there in the future.

When I had the M90 setup, I ran it with a 2.57" snout pulley and a ROUSH 12% over-drive crank.

I went from 435rwhp/415rwtq to 440rwhp/450rwtq!!!
I never had any heat issues...yes my IATs were hot when hot lapping at the drag strip and in traffic, but cooled off instantly as soon as you start moving.

I say do it!!! You'll love it.

I did later go further and install a 2.49" snout pulley. I don't think this was worth it as the throttle response became like a switch. Instant wheel spin in 1st and 2nd. I had to recalibrate my foot. LOL Peak boost hit around 11PSI cooler winter air almost peaked at 12PSI. What a rush with the super whine of the blower!!

I say the best combo is the 2.57" + the 12% OD crank.
I did have to upgrade to the GT500 fuel pumps though...or at least you can do a BAP. You may be able to get away with just a FPDM wiring mod.

You could have had your tuner adjust your throttle response.

 

[AutoXRacer]

You could have had your tuner adjust your throttle response.

True, but my tuner said I did not need a retune going from the 2.57 to the 2.49. The change was minor enough for AFRs to stay spot on.

I didn't mind it. Came in handy in the higher gears.

 

[snopro442]

I also have the gt500 fuel pump set up installed, I just want to make sure that I am not going to hurt anything with the extra heat build up, thanks for all the info.

 

[Captainstr8edge]

True, but my tuner said I did not need a retune going from the 2.57 to the 2.49. The change was minor enough for AFRs to stay spot on.

I didn't mind it. Came in handy in the higher gears.

I was talking about you calling it an on-off switch. your tuner could adjust the actual throttle response so it comes on a little smoother. Its a very simple thing to do from what I understand.