How can a tuner choke or make a bad tune?

[cobrAA]

I'm asking here because on my local forum they're gonna be a tons of hating or a wars agains 1 vs 2 etc etc etc. and screw that.

I got tuned by #1... made 400whp last year on a stock motor with a couple of bolt on and GT-SS..

this year, I was told by numerous person including my machinist and mechanic to got to #2.. he does a better job etc etc, his tune is safer... well now I have a rebuilt motor with poncam and even more bolt on to it.. made 336whp... I played with the car yesterday it's def. slower than last year!

So, I'm wondering what comes to play when tuning a car? I thought like... you have to set the boost controller... and then you have to set the air fuel so that it's always at 12-13..

I mean, how can I possibly make 60whp less HP on a brand new motor with cams ? One use a dynapak and th eother use a mustang dyno.. One tells me that a mustang read a lot more lower.. but I don't believe it anymore because my car is def. slower than last year.

[needavdub]

Well a Mustang dyno is known as the "heartbreaker" for a reason, they read low. My old STi made 331 AWHP on a dynojet and then put down 279 AWHP on a Mustang lol. But if your car physically feels slower it probably is, there's a lot more to tuning than just the AFR's. A lot of your power is made on the ignition timing end of things, maybe your new tuner gave you a less aggressive tune for safety's sake. Or maybe he sucks...

[M13]

Mustang Dyno does read lower than Dynojet, but at the end of the day, numbers don't matter, it's how your car actually pulls that matters.


Go to a different tuner or you have major mechanical issues.

[Dragon Humper]

And FYI, a "safe tune" usually means a lame tune. Some tuners are so afraid of having a motor grenade that they had a hand in that they will keep AFRs fat and the timing curve VERY conservative (usually in the 14 to 18 deg.s range) to make sure that you don't get a batch of bad gas from effing Costco (some are that stupid to buy that crap in the first place) and really detinate the hell out of the motor.

What some tuners don't realize is that a fresh motor needs a crisp tune so that the cyl. walls and the rings can seat properly and not get washed down with extra fuel. Unless it is pig rich a fat tune won't harm the process but it will make it happen faster than it should with the extra fuel removing the oil from the walls. This is only going to happen under boost when the 02 sensor is being ignored and fueling is running off the fuel map. As long as you are driving it really gently for the first 200km you should be good. Moly rings seat themselves much quicker than iron rings (not used much anymore) and you should be good to pound on her after 200km.

You can never trust a HP comparo between two types of dynos, they will never match (and can vary up to 25%). I would suggest that you go back to tuner #1 and have him do another baseline without telling him anything that you have done. That way he won't be inclined to fudge the # to get you to get the car retuned again because he thinks that "tuner #2 has no idea what he is doing" and he can find a bunch of "hidden horsepower".

All things being equal you should be a good 20 to 30hp and at least 30lbft more than last time.



Jon.

[cobrAA]

And FYI, a "safe tune" usually means a lame tune. Some tuners are so afraid of having a motor grenade that they had a hand in that they will keep AFRs fat and the timing curve VERY conservative (usually in the 14 to 18 deg.s range) to make sure that you don't get a batch of bad gas from effing Costco (some are that stupid to buy that crap in the first place) and really detinate the hell out of the motor.

What some tuners don't realize is that a fresh motor needs a crisp tune so that the cyl. walls and the rings can seat properly and not get washed down with extra fuel. Unless it is pig rich a fat tune won't harm the process but it will make it happen faster than it should with the extra fuel removing the oil from the walls. This is only going to happen under boost when the 02 sensor is being ignored and fueling is running off the fuel map. As long as you are driving it really gently for the first 200km you should be good. Moly rings seat themselves much quicker than iron rings (not used much anymore) and you should be good to pound on her after 200km.

You can never trust a HP comparo between two types of dynos, they will never match (and can vary up to 25%). I would suggest that you go back to tuner #1 and have him do another baseline without telling him anything that you have done. That way he won't be inclined to fudge the # to get you to get the car retuned again because he thinks that "tuner #2 has no idea what he is doing" and he can find a bunch of "hidden horsepower".

All things being equal you should be a good 20 to 30hp and at least 30lbft more than last time.



Jon.

I agree, I know mustang read lower.. I was actually expecting to make quite the same number.. so a good 390whp would of been fair on a mustang because of the extra bolt-on and cams compared to my 400whp on a dynapak.

I'm telling you... I had some ''fun'' yesterday on the highway ; a GTI got VERY CLOSE to beat me. Am I slow ? I think so!

[evilgtr]

Jon you are spot on !!
A few things : a mustang dyno is not referred to as a "heartbreaker", The only
Dyno reffered to as "heartbreaker"
Is the dyno at Racing greed, it's set to read low so there's no disappointed customers when they take their car somewhere else. I know this iv had my
Car tuned their twice.
All dyno's should read within %5 of
Each other if they are set up correctly regardless is it's manufactured by Mustang or fisherprice. Lightspeed had a mustang roller dyno and a dyna-PAC 9000 from New Zealand. He recently did a comparison with the same car back to back dyno runs on both and the difference was only +5whp for every 200whp (the dynapac was +5whp higher) so do the math it's only a couple percent. Certain tuners will manipulate their dyno timing values and other parameters necessary to increase the power and give the customer false HP so they think he is a stud tuner and he is doing things no one else can. 6 weeks ago I had my car on a dyno in a car show and it put down 419whp at 14psi on a mustang. Last week I put it on lightspeeds dynapac and laid down 421whp at 14psi. Now all things considered, cold engine,increase in elevation by 1133feet I'd say that's pretty damn close.

If your not happy with your tune try another shop,some guys are geniuses with RB motors others are to conservative because they simply don't know and want to be cautious. I found a tuner I trust and that means me trailering my car 9 hours everytime I want it tuned.. Or send it to Jon
Jon you should a tuning shop in sask !

[evilgtr]

Jon what are your target a/f's at wot and peak ign timing ? I can't remember what I'm at with meth but does 22 sound right and a/f 12 ?

[Zacho]

I'm asking here because on my local forum they're gonna be a tons of hating or a wars agains 1 vs 2 etc etc etc. and screw that.

I got tuned by #1... made 400whp last year on a stock motor with a couple of bolt on and GT-SS..

this year, I was told by numerous person including my machinist and mechanic to got to #2.. he does a better job etc etc, his tune is safer... well now I have a rebuilt motor with poncam and even more bolt on to it.. made 336whp... I played with the car yesterday it's def. slower than last year!

So, I'm wondering what comes to play when tuning a car? I thought like... you have to set the boost controller... and then you have to set the air fuel so that it's always at 12-13..

I mean, how can I possibly make 60whp less HP on a brand new motor with cams ? One use a dynapak and th eother use a mustang dyno.. One tells me that a mustang read a lot more lower.. but I don't believe it anymore because my car is def. slower than last year.

I could make it long, but in short if your car is definitely slower (100% sure) then the tune has to be garbage, or something mechanical is holding you back (mechanical timing incorrect/engine problems/whatever). But something everyone should know is don't stress the actual figures so much. You need to hit the track/use a reference to really see if there is a difference in performance versus before.

As far as what goes into tuning a car properly...well it isn't as easy as just setting afr and boost and calling it a day. You have tons more parameters and conditions.

[gtrjon]

evil who is this tuner that you trust so much? im guessing andrew?

[Skym]

I've noticed there's 2x types of tunes used on new engines. One is a break in tune (less rwhp or awhp) and the other is a power tune that's done after break in.

[nelsonmxmarc]

Alex, are you talking about ACSP? The numbers there are very conservative.. A guy running his built SR20 made like 315.. then 400 or so with Robin. There's a discussion on MR i think.

[Dragon Humper]

Jon what are your target a/f's at wot and peak ign timing ? I can't remember what I'm at with meth but does 22 sound right and a/f 12 ?

I run really good fuel all the time (about 96 to 98 octane with 10% methanol mixed in for good measure) so my #'s are NOT something that you want to gleen from. My AFR's are in the 12.2 to 12.3 range (you can be a little lean with 15% alcohol mix, 5% ethanol + 10% methanol) and I am running 32 deg. of ign. timing from 3500 all the way to 9000 at up to 1.5bar, it pulls back a little above that. I pulled a little timing out over the J-land tune at the torque peak (about 3 deg.) because that is where the cyl. pressures really max out. I also added a whole bunch of timing in the full vacuum to 0bar (no vac, no pressure) to bring the boost in sooner and make the off boost torque curve much better. At 8.5 to 1 and tiny little bores you can get away with a lot. The only time I let the timing get near 40 deg. is in a light cruise (lean cruise, 16, 17 to 1 AFR) situation with not much load, that's how I can get close to 30mpg on the hi-way and up to 20mpg in town (if I stay out of the boost...lol).

The fuel mileage alone is worth a big single, with virtually no boost being made below 3000rpm I can cruise the car around like it's a Sentra sipping fuel, when I want to pound the snot out of a ZR1, all I have to do is call up the big boost on the controller and rev her past 4500rpm.



Jon.

[Black BNR32]

evil who is this tuner that you trust so much? im guessing andrew?

cam at Lightspeed in red deer

[evilgtr]

^ thanks I must have missed that one from Jon.
Yes Cam tunes my car but Andrew built my motor

[DreadedFist]

Dynos are a tuning tool, don't look at the number produced, look at the percentage gain of horsepower/torque that is the result of mods and/or a tune. AFR doesn't make the most power, ignition timing does. This is why you can tune for 10:1 under load and still make great power, you just need more ignition advance. On the flip side, you can run 12:1 under load, but can't use nearly as much ignition advance.

Different philosophies. Rich with lots of ignition is safer, exhaust gas temps are lower. 11 or 12:1 under boost with less ignition will run hotter exhaust temperatures. Less ignition advance + less fuel = hotter which can = more likely to detonate.

IMO, for purely a street car, you can get away with 12:1 under wot because how often is a street car being driven hard enough to get EGT's hot enough to cause damage? On the flip side, for a car that does nothing but wot pulls through the gears, assuming you aren't using race fuel, you'd probably want more fuel and ignition to keep things cooler.

Source: I'm making it up as I go.