Had the Bullitt on the Dyno for the first time (results)

[eighty6gt]

I have a gauge. 7.5 psi on the hottest days, 9.x when it's nicer out.

To think, I bet I have 2x the value of a DOB kit into the blower on my car, soon to be running 150F IAT's. I'm hoping Brian is talking about the 63 pulley and OD balancer, under light cruise.

 

[BruceH]

This baffles me. 86GT only has the 82mm pulley on the VMP TVS-1900.
(they range from 85mm-63mm). He also has the larger roush 18" tall x 21" wide HE....along with the newer 2013/14 GT-500 IC pump. (which turns the de-gas into a jaccuzi). On paper, the new 1900 should have a helluva lot lower blower discharge temps (pre-ic) vs a sped up M90. ( it also uses the high flow elbow). One thing the VMP TVS-1900 does have going for it though is it eats up a lot less hp. That's free hp.

Chopping out the vanes does work with the 2.49" pulley and just under 9 psi boost, like another 7 rwhp. The signal coming from the maf sensor however is slightly distorted with the vanes chopped out, so the tuner has to do a slight tweak. (the vanes were installed to straighten the airflow past the maf sensor). Dunno how effective the chopped out vanes will be with the lower boost, like oem 5.8 psi, but it's a simple mod.

Brian is fortunate he lives 10 miles from VMP. I don't think 86GT has a boost gauge installed, but the 85mm pulley is typ 7.7 psi. The 82mm should be very similar to the 2.49"..c 8.9 psi.

Sensor placement can make a difference as can driving styles and areas. Brian is in FL where the weather can be hot and humid.

I'm of the opinion that a larger blower would have lower iats. Maybe the manifold design has something to do with the temps? The only way to know would be to put a 1.9 on something designed for a 2300 and I'm pretty sure that's not a direct swap so it's not going to happen.

The easiest way to combat higher iats is with e85. High iats just don't matter because it's not going to detonate and it will cool the entire motor with the combustion process. Like Stephan noted it also cooled his iats because his blower didn't absorb as much heat from the motor. If it's available try it. A fuel injector and pump upgrade is a whole lot cheaper than all the other things mentioned and the power increase just from the fuel change is significant. I saw over 75rwhp in the lower rpm range going from 92 octane to e85 and this was keeping the same spark advance table used for 92. Edit: This was with a 2.3 Whipple and 9.5 compression motor. The peak gains were around 45rwhp once the fuel pump and injectors were upgraded to allow for a full pull and the spark advance table was increased for e85.

This is a total guess but I'm going to do it anyway. The OP should get at least 30rwhp with a switch to e85 and the same spark advance, basically the same tune with only the fuel stoich changed. Once he added max effort tune (I'm thinking the Roush tune is fairly conservative) he should see more hp. All for about $350 in components and maybe 1 hour of labor. Add to that the fact that he wouldn't have to be concerned with iats and he could still go with a smaller pulley if he wanted the benefits are even greater.

 

[eighty6gt]

Eventually I will tire of the forced induction blues, and switch over to a 322 cubic inch n/a 3 valve.

 

[Pentalab]

The VMP TVS-1900 blower is very eff in the 7-14 psi range. It's more eff than the 2300. A 2300 is just a 1900 , but longer. ( but the same 4 lobe, 160 deg twist). If you look at the blower mapping from eaton on the 1900 vs 2300, that is readily apparent. The dark blue 'islands' are a lot bigger on the 1900. The M90 is aprx 1.48L. The M122 is exactly 2 L.

I think what scares folks off E85 is availability out of town. Bruce, can u take a eng modified for E85....and use 91/93 in it, if you are in a bind? IE: bring your SCT along for the trip, with a 91/93 tune in it.

 

[eighty6gt]

Efficient, not efficient, maps, etc... the sensor sees 130F.

 

[BruceH]

The VMP TVS-1900 blower is very eff in the 7-14 psi range. It's more eff than the 2300. A 2300 is just a 1900 , but longer. ( but the same 4 lobe, 160 deg twist). If you look at the blower mapping from eaton on the 1900 vs 2300, that is readily apparent. The dark blue 'islands' are a lot bigger on the 1900. The M90 is aprx 1.48L. The M122 is exactly 2 L.

I think what scares folks off E85 is availability out of town. Bruce, can u take a eng modified for E85....and use 91/93 in it, if you are in a bind? IE: bring your SCT along for the trip, with a 91/93 tune in it.

Yes. I'm mostly running 92 octane with 12:1 na and I've run 92 with 12:1 and 7psi in the current configuration. All it really involves is keeping the knock sensors on and keeping spark advance sensible. I can't say that I'm an expert in the area of what will and what won't work with high compression. What I can do is tell you what has worked in my applications. I've also run 92 with forced induction and an 11:1 motor. Didn't have any issues.

IMO our engine management systems are rewriting what was common knowledge just a few years ago. Engine management will mitigate high iat, ect, detected knock, etc. It's something that just wasn't available back in the day so the rules have changed when it comes to what will and won't work with pump gas.

I personally wouldn't (didn't) go over 12:1 because I knew I would be using pump gas more than e85. If I had gone with 14.5:1 I would of had an e85 only motor that would of (should) put out over 500rwhp and would of gotten about what I get for mpg with 92 octane. However, I only have one e85 station about 10 miles away, there are only about 12 in the entire state so I had to keep the compression at a point that the motor could survive with pump gas.

As far as 12:1 goes I once saw spark being pulled back to 26.5 degrees at wot. This was after getting a tank of gas from an unfamiliar station. Previous to this I had 28 degrees commanded and never had it pulled with 92 pump gas. My own theory is that I got a tank of 89 or 87 but I will never know. I did pull max spark advance at full load down to 26 degrees just in case. What difference it makes on a dyno or at the track I don't know. For most of my driving it makes no difference whatsoever.

A simpler answer would be that yes, running pump gas is as easy as changing the tune.

 

[TRC51]

I think what scares folks off E85 is availability out of town.

Exactly my issue as mentioned early. I loved having the power of a diesel, but the fuel station hunt sucked. As much as E85 is tempting, I just don't see it happening. Although, unlike the diesel I had, I NEVER let anyone fill up my Mustang. LOL

I am torn about the longtubes now. I would love the old cammed hot rod sound that LT's and cams would provide. But, 1 - 2 hours into a pulley change, filter and tuner/tune and I can be at 430hp..... for less money OTD.

So.... did we determine that the 1.9 runs similar IAT's to the M90? If so, and eighty6gt is running less than 10psi.... what was the difference?

 

[Pentalab]

I have a gauge. 7.5 psi on the hottest days, 9.x when it's nicer out.

To think, I bet I have 2x the value of a DOB kit into the blower on my car, soon to be running 150F IAT's. I'm hoping Brian is talking about the 63 pulley and OD balancer, under light cruise.

Why is ur boost down on a hot day..and higher on a cool day ? Mine doesn't change between winter and summer. Are you folks vacuum filling your ic-he-degas-pump loop ?

I think Brian swapped everything to a 8 rib setup....on his built motor, complete with I think 63mm pulley and I think a 10/12% OD crank pulley. VMP makes the 85-82-79-75-72 pulley in 6 rib.....dunno about 8 rib. They say the 66+63 are 8 rib only. b4 his car with built eng got totaled, Brian mentioned going to a bigger pulley for DD use, to combat IAT's in warm wx.

If he was getting 150F iat's with a 63mm pulley (and possibly a 10/12% OD crank pulley), that would not surprise me..esp on a hot day. I forget how much boost he had with that 63mm pulley, think it was around 13-15 psi. That's under boost conditions. No way will your iat's ever be 150F while just cruising. Mine sit at aprx 122F on a hot day while cruising on a 75-80F warm day. drop down a gear or 2 and iats drop. Mash the gas, and iat drops a bunch..like down to 111-115. They don't rise much after a few secs. I can modulate the iats with my right foot. While cruising, the airflow is so slow, it picks up a ton of heat from the hot al manifold (which also has the integral eng coolant cross over built into the leading edge).

Increase rpms a bunch, and airflow is in and out of the manifold so fast, it doesn't get as much of a chance to pick up heat.

VMP tells me that the oem Roush tune had the timing pushed out to 29 degs..and the timing did not get pulled till iat's hit 150F..but that's for the oem roush 5 /5.8 psi setup. Most tuners set the iat threshold at 135 F if typ 8-15 psi boost levels used.

Brian mentioned his iats (under boost) increased at 5-8 deg F for each lb of boost. If you run 10-15 psi boost, I can see iats getting out of control.

Part of the issue with the M90 is the IC is not very big but it's the same size as used in the old cobra with the M112 blower. But that can be overcome by increasing the IC pump, then you can extract more heat with the smaller IC. On the hwy, fan(s) on the HE won't buy you anything, their velocity is way too slow, like 14-18 mph. What probably would work is the 3.125" thick HE from the 13/14 GT-500..plus the mating 13/14 larger 8 gpm pump. That plus use the min boost you can get away with, and maximize gains from everything else. LT's / TB / cams / heads / E85 / higher CR / etc.

 

[Pentalab]

Exactly my issue as mentioned early. I loved having the power of a diesel, but the fuel station hunt sucked. As much as E85 is tempting, I just don't see it happening. Although, unlike the diesel I had, I NEVER let anyone fill up my Mustang. LOL

I am torn about the longtubes now. I would love the old cammed hot rod sound that LT's and cams would provide. But, 1 - 2 hours into a pulley change, filter and tuner/tune and I can be at 430hp..... for less money OTD.

So.... did we determine that the 1.9 runs similar IAT's to the M90? If so, and eighty6gt is running less than 10psi.... what was the difference?

VMP came out with a TVS-1900... that is a direct swap for all these 05-10 M90 blowers. The new 1900 just bolts onto the same oem Roush al manifold. The supposed advantage of the 1900 is / was... it's supposed to be a helluva lot cooler blower discharge temps (pre-ic) vs the M90, lb for lb of boost.....and also use a lot less hp to drive the blower (like 28 vs 72 hp for 8 psi.) The M90 isn't even capable of >10 psi. To get 10 psi on a M90 requires a 2.49 pulley + 12% OD crank pulley.

Folks with the M90 and also the 2.57 / 2.55 / 2.49 pulley all report another 2.5 to 3 psi additional boost, but IAT's under boost conditions is a helluva lot hotter. With the smaller pulley, the M90 is way out of it's eff range..and is cranking out a lot of extra heat (pre-ic). Another way to combat higher iats is to use 100% distilled water + water wetter. Then you can extract more heat in the IC. That's fine, provided your HE is big enough to dump the extra extracted heat. (then go back to a 50-50 water-glycol mix in winter). Carmen (redfire427 on the roush forum) managed 488 rwhp on his M90... but used water-meth injection, with a a pair of 225 ml sprayers on the blower elbow. ( + FRPP hot rod cams).

 

[BruceH]

Why is ur boost down on a hot day..and higher on a cool day ? Mine doesn't change between winter and summer. Are you folks vacuum filling your ic-he-degas-pump loop ?

It has to do with weather. Hotter air is less dense while cooler air is denser. This is why pilots pay attention to density altitude aka da. An airplane will have more lift on a cooler day due to the change in da and resultant change on air pressure and density.

Winter is when you see higher than normal hp numbers and the fastest quarter mile times along with fueling issue blown motors, all because of favorable da.

The denser the air is to start with the more a blower will be able to force into the motor. This results in more boost being measured due to the density of the leftover air that can't go through the motor.

 

[Pentalab]

It has to do with weather. Hotter air is less dense while cooler air is denser. This is why pilots pay attention to density altitude aka da. An airplane will have more lift on a cooler day due to the change in da and resultant change on air pressure and density.

Winter is when you see higher than normal hp numbers and the fastest quarter mile times along with fueling issue blown motors, all because of favorable da.

The denser the air is to start with the more a blower will be able to force into the motor. This results in more boost being measured due to the density of the leftover air that can't go through the motor.

Got it. The denser the air, the heavier it is. Mass airflow is another measurement of weight of air. I also noticed on low pressure days vs high pressure days, the 'zero' point on my Roush boost gauge moves around / up / down a bit. The 'zero' point on the roush boost gauge is a marked off narrow band.

On low pressure days, the zero point shifts down a bit, yet the boost stays at 5.8 psi. But relative to the lower referenced 'zero' point, the boost is actually a bit higher.

My driveway is 300' above sea level. Most of the time I'm driving around town between 7' and 200' above sea level. One cold, clear feb day, a bunch of us went for a drive down by the waterfront. The GT-500 folks had loads of power, and IAT's were not an issue, esp when it was like 38-40F outside. Loads of hp... but nobody had any traction. On a hot summer day, the 'zero' point shifts up a tiny bit, but still the same 5.8 psi. It rarely gets above 85 F here in the summer. More like 68-77 F.

Still, 86GT's 7.5 psi to 9.x psi spread is a lot more than my 'zero' point moves about. But then again, his hottest summer days are really hot, but dry. Humidity here never goes below 55%, even on the hottest summer day.

 

[eighty6gt]

I thought my belt was slipping when it warmed up. Boost came back when it cooled off.

Getting pricing on MAC LT's and a pro chamber, thinking that muffler they put in the midpipe might help quiet things down.

DA is always terrible here - cars run very slowly at the local track. I'm most impressed watching the vanilla hemi doge challengers/chargers. Automatic transmissions. Launch with TC on, off, in reverse, window down, fat driver, skinny, radial tires, slicks, cai, exhaust, nothing, etc... 12's every time. No drama.

Hellcat ran, I think it was in the 13's.
Reviewed logs...
My IAT's with full throttle passes with the M90 were 112F. Same exact conditions 96F with the 1.9!! Huh. Cruising is where the 1.9 is as hot or hotter. Bypass operation is interesting.