Another OHV M90 build

[Dono]

Tim was over last night, and brought Evil with him. Evil's crazy fast. On dry pavement, from a stance in 4wd, she lights the tires right up. definitely a mustang v8 killer at lower speeds, even with its weight.

Tim gave me a smaller pulley than what I have on. It looks to be about a 2.5" compared to my 2.8" I'm running now. I'm certain I will get belt slippage with it, but might try it anyway once I'm ready to start tuning. Im interested to see if it gets me up to the 10-12lbs boost range.

 

[jd4242]

Tim was over last night, and brought Evil with him. Evil's crazy fast. On dry pavement, from a stance in 4wd, she lights the tires right up. definitely a mustang v8 killer at lower speeds, even with its weight.

Tim gave me a smaller pulley than what I have on. It looks to be about a 2.5" compared to my 2.8" I'm running now. I'm certain I will get belt slippage with it, but might try it anyway once I'm ready to start tuning. Im interested to see if it gets me up to the 10-12lbs boost range.

Yea ive seen his youtube vid.one sick ass truck!! 2.5 is what I just ordered, by my calculations it would put me right at 12lbs.you going to try it before any tuning? I would be worried about that big of a jump in boost without some sort of base tune for it.

 

[vroomzoomboom]

and if i go to the even smaller pulley, we will see what the one i have on will do on yours.

btw, if it makes any difference, the tuner i have is a X3 part #3000. the original purchaser bought it in dec 31, 2008. maybe ask james if there is any difference between your an mine.

 

[jd4242]

and if i go to the even smaller pulley, we will see what the one i have on will do on yours.

btw, if it makes any difference, the tuner i have is a X3 part #3000. the original purchaser bought it in dec 31, 2008. maybe ask james if there is any difference between your an mine.

Do you all have to mill your snout down to clear these smaller pulleys? I know the gm m90 anything smaller than a 2.7 and you have to mill the snout to clear the pulley

 

[Dono]

I actually put my pulleys on backwards. This makes up for my belt allignment issue perfectly.

I had to drop the pulley on just to see if there is a boost difference. Guess what? None really.

Ok, WTF? belt slippage...has to be.

 

[jd4242]

I actually put my pulleys on backwards. This makes up for my belt allignment issue perfectly.

I had to drop the pulley on just to see if there is a boost difference. Guess what? None really.

Ok, WTF? belt slippage...has to be.

You using new belts for each pulley? Should be a difference for sure.

 

[vroomzoomboom]

I actually put my pulleys on backwards. This makes up for my belt allignment issue perfectly.

I had to drop the pulley on just to see if there is a boost difference. Guess what? None really.

Ok, WTF? belt slippage...has to be.

geeze, that didnt take long. what happen to "oh i think we will wait till we can make another idler pully" lol

don, can you get a diameter measurement of one of your idler pulleys thats on the motor easily? what we can try is if you have one thats smaller then my old ones is swap them and see if the belt will tighten up.

 

[Dono]

Yup, Im using the same belt. I could go one size smaller, looking at how tight the idler is.
Tim, I'll measure the diameter tomorrow.

I dont want to buy another belt to tighten up, then buy yet another belt when another idler is added to get better wrap around the SC.

I did just figure I'd try the smaller pulley, just to see the boost pressure difference. I'll just leave it on now though.

One night next week I'll calibrate and drop in my wideband sensor in my exhaust. Ive been waiting for my usb to serial adapter (ebay) to show up, but I can still calibrate and log without it.

 

[jd4242]

The first gen idler pulleys are the largest ford makes.you should have a smaller one, should be same as the 5.0..idk how that belt works for all three of those pullies.its gota be slipping.when I go from the 3.2 to the 2.7 I have to use a half inch smaller belt just to have enough tension on it.where you planning on putting a belt slip pulley at?

 

[Dono]

For me. the extra pulley would be on the right side, kinda between the air conditioning and the SC. that would make at least 3/4 pulley wrap on the SC.

The pulley bracket will have to go on standoff's off the front of the head.

 

[Dono]

I was a bit premature (Or maybe not) on not seeing any more boost. On the way in to work, after driving for about 30min, I saw 10lbs boost consistently when hard on the gas.

So, this tells me that if the belts good and warm there isn't as much slippage (Maybe none? impossible to know for sure).

Each smaller pulley gives better drive-ability at lower rpm's also. My trans drops in to overdrive much quicker when cruising and is more inclined to use the boost rather than downshift. On that side, it has to help gas mileage.

 

[jd4242]

How are you measuring/recording boost boost? Just by a gauge? When are you seeing 10lbs, at what rpm and load? I know with my naked eye on my gauge I am not quick enough nor is the gauge to see real boost levels. I peak at redline on the dyno at 9.8lbs but naked eye I can only see 7-8.happens to quick.you may be hitting way more than you think or can see.

 

[Dono]

Yes, thats possible. I have a max recorded boost button on my gauge, and I reset it last night. Checking it today is about 10 lbs max. Even then, reliability of gauge comes in to play. Mine isn't a high quality AEM, or anything like that.

 

[jd4242]

Yes, thats possible. I have a max recorded boost button on my gauge, and I reset it last night. Checking it today is about 10 lbs max. Even then, reliability of gauge comes in to play. Mine isn't a high quality AEM, or anything like that.

Do you? Thats a pretty cool feature.well im sure its pretty damn close then.

 

[vroomzoomboom]

10lbs? wow. maybe for poops and giggles we should rip the one that i have on off, and put it on yours, you know, just to see.

 

[Dono]

10lbs? wow. maybe for poops and giggles we should rip the one that i have on off, and put it on yours, you know, just to see.

hahaha.....
I need to get that o2 sensor installed and start the tuning process. I'm starting to hear detonation, even at part throttle.

 

[Dono]

Log sent to James. Tims pulley is creating detonation at part throttle when the trans is in overdrive. Not showing any boost, but I guess the SC is still pushing extra air in to the motor. A/F ratio is constant around 14.5 with the detonation happening.

I tried to compare iat's, but looking at the logs in excel, its pretty tough for me to compare against old logs. It does seem to be working though.
Heres a chunk under load:

RPM:4759 Load: 0.807 intake air:188 iat_sensor_temp:133 Spark_Advance:10.25 A/F Ratio:10.8

 

[Dono]

Just a guess, but Im betting James will be adding a bunch more timing back at wot.
With temps down, it would be awesome to see that 10.25 spark advance go way up.

 

[vroomzoomboom]

he's going to start hating both of us soon

 

[Dono]

Funny thing is, I was thinking the same thing as I was sending him my log.