...to make my torque curve look like the red line in either of these two dynos? Numbers don't matter to me, I just want the rate of accelleration to keep increasing as the RPM gets higher. Thanks in advance

 

The only way I can think of off hand to get a torque curve like that is to use a variable geometry turbo. Integrating a VGT on a MCS would be hideously expensive as you would need the turbo, the whole control system plus tons of tuning to get things right.

Scott
90SM

 

I'm not sure what the torque curves of the twincharged cars are but you might want to look into it. The SC will give you low-end and the turbo should keep it coming as the revs increase.

 

get a tune on your car that doesn't make your car go pig rich in the mid and upper portions of the rpm... that will help significantly!

 

I've noticed the that torque curve on the JCW cars don't fall off as bad as the MCS, and this must be one of the reasons why (JCW ECU). The other mods I've been looking at that could also have this affect would be a lightweight flywheel, and a revised cylinder head. Does anyone know if the JCW head has more high rpm torque than the one offered from Outmotoring? Thanks!

 

because if you have a torque curve like what you want, you'll just rev higher to when the torque curve falls off.....

On a more serious note, my head work has flattened the torque curve up top, and raised it all over the place, but I didn't go for a screamer race head that's optimized for top end.

If you're not going to get into the head, and just stick with bolt ons and tunes, then you'll get some version of the curves that you've posted. It's just the nature of the beast.

You're also fighting the tendancy of the M45 supercharger. It doesn't really come on until 3k or so, and as it spins real fast it's efficiency drops off due to gas heating, so you'll find the torque peak on pretty much all non-turbo set ups peaking between 3-5k.

Matt

 

I figure that porting and polishing will help with the high end, beyond that what other things would help? Bigger valves? Lighter valves? Where does the schrick cam provide most of it's power?

And I'm going to stay away from a new pulley since it'll most likely have even worse efficiency issues at higher rpm than the current stock pulley.

 

is building up to a strong street plus motor. I do a few track days a year, but don't race, drive the car hard, and live in really fun hills. So I aimed my mods at that and will be happy with the compramise package that gets me there, and there will be a peak torque that is below red-line, and I won't mind. Shift points are a function of the torque curve and gear ratios. But if the HP curve is still climing at red-line, then you can bet that that's where you;'ll be shifting for fastest ETs. Not exactly true, but close.

So, the Mini has problems with the exhaust side of the head. I went +1mm there, and +0.5 on the intake valves. This doesn't hurt torque or power anywhere as far as I can tell, and allows a bit better breathing at the high end. (I'm aiming for a 7500 RPM red-line)

I don't have the Schrik, nor do I know how it really works out. I've read conflicting reports on whether it helps at the low end, but there's pretty much universal agreement that it gives something up top. Since this is where you want help, it seems like it might be a good fit.

Contact one of the builders here (there are lots that can help) and discuss exactly what you want to get out of the car, and work with them. This is the best (only?) way to get real good value as you go beyond the just bolt on stage of mods.

Matt

 

Looks like I'll go with the ECU tuning route and see how it goes, and add go for a new head, flywheel, and exhaust later on...

Thanks!

 

A couple of thoughts...
What rotational mass differences have you made to your car? I ask because a stock 2005 MCS makes 168 hp at the crank (145 hp at the wheels). If you have are stock then this dyno is reading about 17% too high -- it is out of calibration. If you wheels/tires weigh less than stock that could be some of the discrepancy.
Do you trust the air/fuel reading? If so, you ought to get that sorted.

 

That's not my dyno , I just grabbed one of more clear dyno pictures to show the torque "curve" I am looking for. Thanks for the concern, though.

 

Which ECU tuning would provide more "top end" power? I've read that the MTH Tuner software's power is more noticable in the 3-4k RPM part of the powerband, and I'd rather have it in the 5-6.5k area of the powerband.




Thanks

 

Who gave you that information and what is the basis for that claim?

 

hey, thats my dyno (factory JCW car with 14.3 lb 17"Trak-Lites in place of the stock S-heavies)!

as far as the A/F goes, I have reason to believe it (I saw it, and it ran like this for 3 other pulls), and thats factory JCW, probably just a bit over conservative in the higher rpms, but they are probably just being overly careful trying to avoid knock (since they have to warranty the thing). I'd bet it would be closer to the line if it was leaned out a bit up high, but it'd be hard to say if the cylinder pressures and temperatures would be ok to do so without knock (at least hard for me to say b/c I don't know. . .), since the supercharger is being driven fairly hard (and roots chargers aren't the best at not heating the air when compressing it).

What do you mean by "you should get that A/F sorted" dmh? Its factory JCW software, what issue do you take with factory tuning, other than it obviously being a little conservative on the A/F ratio? What A/F do you recommend at redline for a car with 15% pulley, intake and exhaust? How much hp do you think could be gained from raising this A/F ratio to your recommended A/F at redline (just looking for your best guess here, not a number I'll hold you to later. . .). Would you recommend pulling ignition timing as well to compensate, or just leaning it out til it gets closer to knocking? Just interested to pick your brain a bit, interested to know how you might tweak a JCW cars factory software. . .

 

 

I mean that it is way rich and needs to be corrected if you want to see the engines power potential. I will not tell you exactly what or how I would do it in a post but suffice it to say I have done numerous JCW cars. These are simply conversations to have on the phone or in person.

 

were really weak in the lower RPM bands.... Both MTH and the factory tunes have improved over time....

Matt

 

Hot Rod-
Maybe I misunderstood, what I was getting at was the mid to high power differences of MTH verses the competition. If you were just referring to the Standard verses the Tuning I now understand.
Don

 

I was just curious how much hp you think you might be able to free up on an otherwise stock JCW car, given what looks even to my uneducated eyes to be way too rich of tuning at redline. Not looking for a number that I'll sue you over if I don't make that much hp, just a guess. Are there any dynos of JCW cars that you've done that I can look at?

 

One way to add some TQ via a bolt on mod will be with the addition of a header.

An ECU remap will also help smooth things out as well. When looking at ECU remaps, take a look at at GIAC. Recently a buddy of mine who has been a long time user of MTH, tried GIAC and felt that it did more for HIS car.

Here is his thread https://www.northamericanmotoring.co...ad.php?t=87762

Here is my thread on GIAC
https://www.northamericanmotoring.co...u+giac+upgrade

 

GIAC, though a good product, actually does less than MTH. MTH grows with engine modifications, alters the DSC, raises the rev limit to 7200, and alters the fan control. As far as base power the two are similar but once you add modifications…And with MTH you do not have to see a dealer -- you can do it yourself.

 

Giac also raises the rev limiter, i believe they touch the DCS and I do not know if they touch the fan. As far as "do it yourself" here is something i posted previously .........

"After a year of reading all of the ECU posts this what I mentally put together.

MTH

Pro - most customizable software non-piggy back system. The tuner option is designed to take you from no mods to all of your mods in a 12 month period. Greatly, improves the vehicle.

Con - Service. There is a history of poor and slow service however there is a new US player for MTH (Don of Presion Mini) and since his involvement have only heard positive things .

Neutral - Install, its do it yourself. MTH provides the file and Cartune software. You need to have a PC and purchase the necessary interface cable. I say this is neutral because for some this is positive and others this is a negative. Another neutral is their file library while vast, it has taken some more than one file to get the "right one" on their car. Again this is neutral because it is the price one might pay for true customization.

Another semi-con is that I do not get the sense that if they advance a particular file (i.e. for a set of specific mods) that MTH users of the old file are automatically updated / advised. Only via the board do people hear about a new version and the user must request it. If I am wrong here someone please correct me.

GIAC

Pro - Install - easy, done by local distributor. 30 day money back policy. After reading many, many post; I did not find one person who expressed any disatisfaction (MTH cannot say the same). Greatly improves the vehicle.

Con or Neutral - limited file options 1) 15 pulley (which I understand was developed for a car w/ 15/cai/catback) and 2) 17/19 pulley (which I understand was developed for a car w/ 17 or 19/cai/catback) but requires larger injectors. If you plan on doing more its is a CON.

The decision on which one is right for you is based on the degree of mods you intend to do and the install process which is more appealing (i.e. GIAC is more simplistic than MTH). For me it was easy - In my case BOTH had files to adress my MODS and I would have been equally happy but I found the GIAC install process more appealing.

Bottom line - both greatly enhance your vehicle, as a MOD it comes in second right after the pulley and is a must in my opinion."