...besides a 15% pulley, which I am installing today. Most of my driving is done between 2500-4500 RPM, and I don't like to keep the motor spinning too fast except for on track days.

Any suggestions as to which mods will boost torque in the low end of the powerband? The goal is to get some more "useable" horspower and torque, I'm not interested in adding ponies up in the 6500 range.

Thanks!
J.

 

a lightened or even lightened/larger crank pully would prob help the engine spool up faster. Other then that, ecu flash, lighter rims, lighter flywheel... the list could go on but then so does cost.

 

Wheel/tire change (perhaps lowering the overall gear ratio, but definitely reducing the rotational inertia) and ECU mods are the only reasonable things that will affect the low-RPM range without side-effects.

I'd suggest lightweight 15x7" wheels and 205x55 or even 205x50 tires, which can lower the gear ratio by 3-5%.

 

Oops, forgot to mention that I did switch tires & wheels- 17" forged Motegi Traklites (14.2 lbs each) and Kuhmo Exsta SPTs. I kept the 17" size for the reduced sidewall profile which I prefer on the track. Overall, I like the combo and it has save me a good deal of rotational weight.

What about a header? After some searching I've found some conflicting dyno charts...some show a good torque gain early on, while others show the gain only above 6000 rpm...

 

Try the Cosworth Head the smaller values should help you with your low end. http://www.customminishop.com/product/m7-chead.htm

 

Conventionally speaking, a 4-2-1 header should help increase mid-range torque and power, while a 4-1 header should increase top-end torque and power. Lots of choices here - good luck!

 

Not necessarily in any particular order of priority, but...

1. Lighter wheels and tires. Reduce rotating mass and on the road, it is like picking up ~20 ft/lbs. of torque. Reduced rotating mass also helps with braking distance....

2. 17% s/c reduction pulley. The 17% pulley pushes the torque gains further down the power curve.

3. Cam (and head that can use the cam) that is tuned for lower rpm output.

4. ECU tune that is optimized for lower output.

5. CAI and Exhaust that allow the head and cam to do their thing without restrictions.

Actually, these are probably all tied together in a package.

 

5.0l V-8?

 

a header will add mid-range torque.

 

Smallest supercharger pulley in production and the largest crank pulley that will fit. Which equates to 19%+4%=23% reduction. I ran that setup for 10k plus miles no problems. Was awesome crusing on the highway in 6th gear.

 

Great idea; but what about weight distribution? Unless of course, you are proposing a mid-engined configuration....

 

GO GIAC i got 12lbs. torque down at 1800 to 5000 rpms over prior. only 4 hp more but the torque is awsome.

 

Well how about you add some 380cc injectors... Then install an apexi AFC. Then when you cut the fuel back you will also be adding timing. And as long as the intercooler doesn't head soak on the dyno you will pick up a noticeable amount of HP and TQ.

 

Hey, he asked about low end torque, although if you could squeeze a side oiler 427 mid engine, a 9" with a set of 4.56's out back, now that would ruin more than a couple of peoples days!

 

Your math is all wrong. That isn't how ratios work.

 

Please enlighten me...

 

Well, without looking up the ratio of the two pulleys, let's pretend it is 1:1 to start. If you reduced one pulley by 19% and increased the other by 4%, the ending ratio would be about .779:1 (or 1.284:1, depending on which way you look at it), for a total equivalent "reduction" of about 22%. You can't add the decrease of one pulley and the increase of the other to arrive at a meaningful figure. This can be MUCH more exaggerated if the two pulley diameters are not 1:1 to start with (I am too lazy to look up the actual diameters).

Hope that helps.

 

True but I believe the Alta crank pulley is calculated to be the same as decreasing the supercharger pulley 4%.

 

I am after the same solution, and after much reading and discussion, I have decided on the following additional mods to what I have (see the sig):
> +4% lightweight Alta crank pulley
> 400cc injectors
> hood scoop and hood vents
> ream the stock header pre-cat to fully opened, and match the stock header flange and gasket to the exhaust ports
> ECU tune by Fireballed (luckily, I'm local to So Cal) If I weren't I might go with GIAC and 19% pulley instead of the +4% crank and Fireballed, since so many seem to have been pleased with the GIAC/19% route.
> NGK equivalent of Denso 24 (next step colder plug from where I am now)
> mod the stock IC as shown in the following thread:
https://www.northamericanmotoring.co...ad.php?t=80549

If that does not keep detonation away, then I go to the m7 DFIC.

REASONS: I have decided that since I have 40000+ mls or 4 years left on my warranty, AND I am in CA, and I don't wnat major headaches for smogging, I will not do any head work yet. AND, it seems to me that unless one does head work, none of the aftermarket headers are all that much bang for the buck. Just my 2-cents.

If I were out of warranty, I would be looking at a head from m7 (Cosworth) with a cam, a header, intake manifold and I'd like to get that Dinan fuel delivery setup if possible along with the DFIC and maybe even the M62. Not sure what pulley setup with this other gear, but, basically, pretty much m7 all the way except for the MTH tune. I think I'd go to Fireballed since they are close to me and seem to have unlocked some of the Siemens secrets.

 

Ahhh, interesting. Can anyone confirm this?

 

I really am not paid by DDM but the 62 gave me about 40lb. I don't know of anything close except the TC of course

OldRick had some good ideas..... switching to 15s will surprise you.....

19%, which I ran is good...just don't red line the engine much and be prepared to lose a belt now and then.... (I lost two in two years)

any of the ECU mods will help but 12 lb from GIAC gets my atention.

I see you an "04" --- get the new gear box 05 - 06 ....

I have ridden in a few Cosworth head cars and like the low end very much.... in all fairness I have only stock and WMS to compare it to.

find one of the discontinued Schrick "steet" cams as they improved the mid range..... I had one and can verify this......

I really like the 5.0 solution.....actually probably my favorite but I need video , pictures and of course a dyno to prove that it really improves the torque.....

good luck.....

 

SpiderX- how low in the powerband do you start to see the extra pounds with the 62? The 62 would be an option for me once the kit is all fianalized and officially on the market.

I did some searching and found out I have a GIAC dealer very close to me...how much should I expect to pay?

I like the 05-06 gearbox idea...good reason to add a LSD at the same time! Might be tough to find though...

The 5.0 might work too...but so would the 1925 Stearns-Knight sleeve-valve inline 6 I have in the garage...425 LB/FT at 1600 RPM! It's almost as big as the MINI though...

 

You might just want to consider picking up a 200 header - like OBX or Megan rather than do this work. you can re-use the stock cat. I think you will get more bang for the buck this route but it will be a few dollars.

 

The TQ curve is pretty nice from about 2500 there is no doubt that 4K is still the "sweetspot"

 

325.00 installed. Ask yor dealre about reflashes (in the even the dealer flashes over) as well as return policy (in the event you are not happy). I was not disappoint - the contrary, I was delighted.