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Very disappointing dyno numbers!!

15K views 170 replies 21 participants last post by  ctgt02 
#1 ·
Well guys i just have to rant, i spent 8 grand on a built motor to gain 7 rwhp. Had it tuned today and it made 460 on 16lbs boost. Its not what i expected to say the least. The tuner said that my v1 s trim is just being overspun and not feeding the stage 3 motor enough air. The flippen power curve looks almost like my stock motor with cams. Anyway i guess i gotta find a t trim or somthing, or have vortech upgrade my s trim if it will be as good as a trim. I dont even know what i want to do yet cause im still pissed.


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#17 ·
My guess would be the heads and cams are too big for your setup. You need more air feeding the extensive port work and large cams. Cars have made right at 600rwhp with the V1 s trim overspinning it to 20psi with a mild cam and stage 1 or 2 head. You pretty much removed all of the restriction with that intake/cam/head setup. I know it's disappointing. I've seen head/cam cars making just as much power as a stock motor car before. I'd probably look into a JT or YSi at this point.
 
#11 ·
16*? dang that seems low to me, but idk about 93 octane being in **** California lol but i believe Joe had my 91 octane tune on like 17* timing or something, i would imagine you could go higher on 93 but idk
 
#13 ·
Stage 3 motor??? Wtf does that mean? Lol. Sounds like you spent a bunch of money on unnecessary stuff or your tuner don't know what he's doing. That blower should be good for more than what you made
 
#18 ·
Ugh this is frustrating but first thing first for everyone in this thread... everything you think you know about boost and what not just forget it because its not true... 20lbs on stock heads doesnt make more hp than 16lbs on TFS heads or any other head. You need to start thinking in terms of air volume. TO be totally honesty the motor with better heads and a lower boost pressure will make more hp normally if the cams are the same because more air is reaching the motor and less being forced back past the impeller.

What is your cam timing set at?

I highly doubt your running 16 degrees timing and 16lbs on 93 octane... If you are then thats a pretty aggressive tune.

Things that will make a considerable difference.

What is your AFR at?

What Cams are you running?

What ICL are your cams degreed at.


Making 500rwhp with an S trim is normally as easy as pulleying it down and adding blower cams.

Is this a 6 rib or 8 rib belt system?

What damper are you running?

What blower pulley?
 
#19 ·
you made alot of power out of your first setup cause you ran meth non-intercooler. a restriction free S trim with meth will produce significantly better numbers than a intercooled setup with meth. even thought the boost numbers are higher the cfm could be choked out.

i had a similar problem when i swapped out my motor. i went down to a small pulley and only made 15# of boost and 450 rwhp on my built motor, ported heads and stock cams. i swapped out my tiny 3 core cx racing ic for a 4 core and went up to a larger size pulley to reduce belt slip. after the swaps i made 511 rwhp and 18# of boost

here is my original post when i did the ic swap

http://www.moddedmustangs.com/forums/99-04/175137-size-matters.html

EDIT: I think you may still be non-intercooled
 
#20 ·
I didnt catch then he switched from Meth to IC but in the end you and I are on the same page... Its not about boost its about total volume of air entering the cylinders... I dont care if its under 20lbs boost or 20inch vacuum... X amount of air will equal X hp.
 
#21 ·
Alright now that i got some sleep and thought about the whole situation. All the cam timing info and stuff is on the sheet. I can post that later when i get home. Im still non ic with meth. The ic was gonna be next on the list. The pulley deal is probably my fault cause i got a iw 10 percent od crank pulley and i put on a 2.87 vortech pulley. 6 rib. But the tuner said there was not much belt slip. I will post the dyno sheet later. I guess i could go with blownstang on this thinking the s trim cant feed enuf air for my setup and make me feel a little better


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#23 ·
Also, have you verified the engine's health? I've seen a brand new engine have 25%+ leakdown due to the engine builder over boring the cylinders too much. A 9.5:1 engine and it was only building 80psi cranking pressure.
 
#24 ·
I have seen posts from members with non-intercooled Vortechs before with the same complaint. They increased boost without getting any gains. Because of the additional heat the tuner had to pull timing to prevent detonation. The result was a net gain of almost nothing. I'm not sure how meth affects the equation but that could be part of the problem. Do you know how much timing was pulled?

If you decide to get an intercooler don't go cheap. You're running too much boost for that.
 
#26 ·
Are you running pure meth or 50/50? What size nozzle?

I agree with above do a leak down test and see what you have. Honestly 10:1 one 15+lbs boost and pump gas is alot I would be running 75/25 meth being the 75% with that setup.
 
#27 ·
Im not sure on the size of the nozzle. But im running the stuff called boost juice from am. Damn, do you really think i should have a leak down test done. Even though i was overspinning the piss out of the s trim with the 2.87 pulley and od crank pulley it probably should have made over. 500 huh. Before i have any tests done i want to hear what mhs has to say. I not sure what to do right know, do i order a really good ic and put my. 3.12 pulley back on


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---------- Post added at 03:35 PM ---------- Previous post was at 03:13 PM ----------

I just talked to jordan at mhs and he said that it should be around 550. He also said that it might need more timing.


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#28 ·
I'm just throwing this out there. Do you think your clutch can handle all the power ? I switch to E85 tune and was expecting more power than my 93octane tune. Only thing I changed for E85 was a larger fuel pump. Once the tuner told me my numbers. I was like WTF. He said that numbers were good. Then I told him what it made on 93. Thus was same show too. So he goes and compares the 2 dyno runs. And found our my clutch was slipping. So I said ok. Now that makes sence. So I just live with it for now. It can hold 650hp. But down the road I'll change my clutch out once it can't hold the power. I'm using a spec 2 + clutch with stock T45 tranny
 
#29 ·
No surprise at your results, since your blowing the same amount of air into the engine as before. It just tells you that the heads, cams, intake weren't restrictions in the first setup. But now with your new setup, you can handle a lot more. The power isn't going to magicially appear unless you give it more airflow and more RPMs. Feeding it the same air at the same rpms will only give you the same results. Time to upgrade to a T-trim, and set the rev limiter to 7k
 
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