Dyno Sheet Questions

[Paul1981610]

Just got my dyno sheet out. My tuner says his dyno is stingy. Just wondering if that is actually possible. It reads 321hp at 5250 and 401 tq at 2500. My car is an 01 with long tubes x pipe and a series 1 Saleen blower at 11.9 psi. With a custom tune. I know the 00 Saleen with a Saleen tune and that blower at 8 psi rated 350 at the flywheel. So I was actually hoping for a little more. What do you guys think.

 

[vertigasen]

Hmm.....

Ok, why cut the run at 5250? If you ran it out to 6k, it should make an extra little bit of power. Maybe 330-340? Although the 00 Saleen was rated at 350 brake hp, that is less than 300 rwhp with with 15% drivetrain loss, and you are already at 321. That is GOOD.

The Series 1 blower (early gen M90) is a horrible blower. You might get more air in the engine if you hire a prostitute and have her blow into the intake! There are people who have upgraded the blower on the series 1 manifold, but it costs money.

Like I said, 321rwhp is not bad on that blower. The problem with running more boost on that blower, it gets hot....REALLY HOT. That is why Saleen switched to the MP90 (gen 4) in 2001 for the Series II.....less heat and the ability to run more boost.

 

[1 Alibi 2]

What kind of dyno ? ( Mustang & DynoJet are the common ones )

 

[Paul1981610]

Unsure of type. My buddy had his dynoed in GA and it dynoed at 415 then he had it done where mine was and it was 355.

 

[1 Alibi 2]

Results on the same dyno will vary based on conditions, temp, humidity, etc. ( SAE J1349 )
A Mustang dyno will always read lower #'s than a DynoJet.
Any chance you could post the sheet ?

 

[Deleted member 38176]

Sounds about right. As vertigasen mentioned, there is no worse blower than the early Saleen blowers. They're horrible.

For comparison, I made 420/415 with a Procharger at 8psi with basically the same mods as you.

 

[Paul1981610]

I am satisfied with my power of my car. Just was thinking my torque to hp ratio seemed weird

 

[Deleted member 38176]

How exactly are you satisfied with the power of your car? You have a blower and making as much power as a heads/cams PI 2V and a full bolt-on LS1. I dont mean to be an ass, but your performance results with a 4.6 V8 with a blower @ 12psi is downright pathetic.

 

[Paul1981610]

Because I don't race. I enjoy just driving it and having something well maintained that's more than stock. And yes you are being an ass. I was just asking a couple questions to better understand the dyno results

 

[Paul1981610]

Once again to my FIRST question can a dyno be stingy. Know of four other guys who have dynoed at other locations and get results. Then go to the place I went and are consistently getting numbers 12-13% lower. The tuner says his is stingy and you can add 12-14% to his numbers. And yes I do believe that is a little off. With the full exhaust and custom tune and the smaller pulley I would bet I am more than just 10-15 higher than the stock Saleen that these came with. I know personally that the stock Saleen tune is very conservative at best. If you add 12% to 321 you get 356 add another 15% for driveline that is 408. That actually sounds about right. Comparing to a friends Saleen with a novi2000 at 425 that feels about right.

 

[sneaky98gt]

Is that blower intercooled? If not, that could account for the power falling off up top (pulling timing to keep detonation away). Even if it is intercooled, that M90 just isn't capable of moving enough air in the higher rpm to keep the motor fed, and that could account for the power falling off, too.

Do you have a dyno sheet to post? SAE vs STD correction (and uncorrected) could all have huge effects on the power the dyno displays. The type of dyno (Dynojet, Mustang Dyno, etc.) also can affect it a LOT.

And yes, some dynoes are just stingy. The one I used to put my car regularly was just a standard dynojet, but it consistently read 6-8% low; it had stock Coyotes in the 345-355 range, full bolt-on 03 Cobras at like 475, etc. I saw lots of butt-hurt folks take their cars off that dyno, LoL!

Regardless of all this, you need to remember that dynos are not a reliable indicator of power. They are only useful for tuning (and even then, they have some deficiencies). The ONLY way of accurately measuring the power is going to the track and seeing what it traps (along with the race weight and density altitude). THAT will tell you how much power the motor is making. Don't listen to the dyno queens that only know how to bench race peak horsepower numbers. My 340 rwhp turd has gone faster than the majority of 500 rwhp cars on this board. I love it when people snicker when I tell them how much power it's made on the dyno, and then I say, "And oh yea, it runs 11.5s at 120". That normally shuts 'em up, haha.

 

[Paul1981610]

Yea. It's intercooled. And yea my tuner says he uses dyno for tuning not seeing how much power he can show

 

[vertigasen]

Ok, start by reading THIS thread.

1) By reading that, and a couple other posts, people are flat-lining HP just above 5000 rpms. This is because of a couple reasons, partly because manifold is horribly restrictive, and flows less than a stock PI plastic intake. The second was that the blower was crap. As you can see, people just can't make power with the series 1. The 2000 S-281 was rated at 350 hp @ 5000 rpms. Yes, only 5000 rpms.

2) The MAIN question you have, yes, dyno's can be different. Mine was tuned on a Mustang dyno to 669/621. A year later on a dynojet it was 718/626. Same car, just different dyno types. In your case, I don't know how much it is off. He says 12-14% off, then it may be a Mustang dyno. So, 321 +12% is pretty close to 360. I don't think you are getting any more than that.

3) The blower itself sucks! I don't know how else to say it nicely. Saleen bought the G3 M90 cheap from Eaton. They had a lot of them because they used them on several GM models in the 90's and the Thunderbird SC.....all v6's. When those programs ended, Eaton had blowers to spare....that's where the 99 (and some 98) supercharged Saleens came from. When Eaton started running low on the G3 M90's in 2000, Saleen moved to the G4 M90. Much better design, a ton better in the VE department. Minor changer to the intake manifold increased power only by 15 hp, but moved the redline to 5800 rpms. It wasn't until 2003, when Saleen did it right by moving to the Series IV, and Lysholm twin screws.

If you get 400+ rwhp from a stock blocked 4.6 with a series 1 SC, you might be the first. I think about the max I have seen with similar mods is ~360rwhp. Even then, the blower gets so hot that driving it much will cause it to pull timing due to the excessive intake heat.

Lastly - A graph is needed to see what is what.