282Bhp from a standard 500

[The Red Baron]

Had a service done and a chassis clean and prep and got an ECU remap while it was there.

Here's the result: Previous 273.6BHP and 292.5lb.ft @ 5740rpm, after 281.9BHP and 284.7 @ 5555 rpm.

More than happy with that, especially as its pretty much standard - just a smooth induction kit from ACT fitted.

[LordGrover]

Yep, looks good. Keeps going past 6,000 RPM too. Which is nice.

Unusual that the IT is lower than ambient though...

[ESDavey]

I got 253BHP @ 4700rpm and 306lb.ft @ 3800rpm... can anyone explain how I can have less ponies but more torque please ? Differant Dyno but even so ...

and then the real question, did I win ?

(I know that its like voltage v amps but never really got it for engines)

and I get max BHP at 4700rpm rather than 5700rpm so have I got a big slow(er) thumping engine versus the Baron's higher reving screamer ?

...just found this quote which explains in terms I understand :
"BHP is how fast you hit the wall, Torque is how far you take it with you
In simple terms BHP is the "work" the engine can do, Torque is the actual turning force is can apply to the wheels."

Edited by ESDavey on Wednesday 23 September 19:32

[The Red Baron]

"BHP is how fast you hit the wall, Torque is how far you take it with you"

To complete the quote...

"Understeer is when you hit the wall with the front, oversteer is when you hit the wall with the back"!!

Looking closer at my RR graphs before and after it seems I traded off some torque for horses. Torque was slightly higher before the remap, but horses were lower. Guess they are closely related and you can't have your cake and eat it.

[Blown2CV]

Pretty much what I got out of mine, although has had straight throughs, precats out and engine rebuild since then, so we shall see!

[GreenV8S]

The Red Baron said:

Looking closer at my RR graphs before and after it seems I traded off some torque for horses. Torque was slightly higher before the remap, but horses were lower. Guess they are closely related and you can't have your cake and eat it.

If the fuel map is the only thing that changed, then from what you have said they have made it better in some parts of the map and better in others. In that case, they would have been better off leaving it alone in the regions that they have made worse.

I suppose it's possible they've adjusted the ignition timing too in which case since the timing is so crude (at WOT it's effectively constant advance across most of the rev range) they might have had to compromise some areas to improve others.

[The Red Baron]

Ignition timing was changed to eliminate some 'pinking'.

I'm pleased with this result, as the torque comes in early and stays throughout.

Am thinking about removing the pre-cats, so would be interested to hear what difference that makes. Do you need to remap the ECU again after removing the pre-cats?

[hiltonig]

for me ditching the dizzy is the way to go

[The Red Baron]

Hiltonig, what is required to get rid of the dizzy? I'm not mechanically minded, but I assume it involves replacing it with a coil pack? Is it a DIY job, or bigger than that? What are the advantages?

[bigdods]

I dont want to rain on your parade but arent those figures a bit low for a 500 ? My Chim 450 made 214BHP / 300 torque last week at the wheels, it has the ACT induction kit and pre-cats removed, main cat still in place otherwise totally standard.

Or am I just showing off

[Chimjunkie]

one of the biggest differences i have noticed between the engine sizes is the power difference through the rev range rather than the peak power.

[spend]

The Red Baron said:

Hiltonig, what is required to get rid of the dizzy? I'm not mechanically minded, but I assume it involves replacing it with a coil pack? Is it a DIY job, or bigger than that? What are the advantages?

You can still run mappable ignition with the dizzy... An option that few seem to consider, but an awful lot cheaper than having to install trigger wheel, coil packs, dizzy bung, new leads... I'm always surprised more people don't use this as an interim development for cost and simplicity when changing ECU's.

[spitfire4v8]

Chimjunkie said:

one of the biggest differences i have noticed between the engine sizes is the power difference through the rev range rather than the peak power.

One of the biggest differences I've seen is the variation in rolling road figures however it's relatively easy to get a 4.5 RV8 to give the same top end figures as a 5litre (you just have to rev it a bit higher), but they lose out absolutely everywhere else .. so you're right in that the hp through the rest of the rev range is the biggest difference.

[Alex]

ESDavey said:

I got 253BHP @ 4700rpm and 306lb.ft @ 3800rpm... can anyone explain how I can have less ponies but more torque please ? Differant Dyno but even so ...

and then the real question, did I win ?

(I know that its like voltage v amps but never really got it for engines)

and I get max BHP at 4700rpm rather than 5700rpm so have I got a big slow(er) thumping engine versus the Baron's higher reving screamer ?

...just found this quote which explains in terms I understand :
"BHP is how fast you hit the wall, Torque is how far you take it with you
In simple terms BHP is the "work" the engine can do, Torque is the actual turning force is can apply to the wheels."

Edited by ESDavey on Wednesday 23 September 19:32

Sounds like you may have some worn cam lobes.

[Lefty Guns]

Nice numbers. Weren't TVR being a bit cheeky in quoting 340bhp new?

[GreenV8S]

spend said:

You can still run mappable ignition with the dizzy... An option that few seem to consider

Definitely true, and a useful half way house, going to coil packs will take more hardware and work but gets you a stronger spark (some won't need it), removes the jitter from dizzy drive backlash, removes the dizzy as a source of HT problems.

[blitzracing]

The Red Baron said:

Hiltonig, what is required to get rid of the dizzy? I'm not mechanically minded, but I assume it involves replacing it with a coil pack? Is it a DIY job, or bigger than that? What are the advantages?

You dont just need coil packs, but something to drive them with and a crankshaft trigger wheel. There is a system called Megajolt that is sold as a kit of parts for acround £400, (or about £250 if you build it yourself with second hand bits) that is fully mappable, but you are at about a third of the cost of replacing the whole ECU at this point so you have to consider if just replacing the ignition on its own is a good way to go. I would think the gains are not huge over a correctly working distributor on near standard engines.

http://trigger-wheels.com/store/index1.html

[spend]

blitzracing said:

There is a system called Megajolt that is sold as a kit of parts for acround £400, (or about £250 if you build it yourself with second hand bits) that is fully mappable, but you are at about a third of the cost of replacing the whole ECU at this point so you have to consider if just replacing the ignition on its own is a good way to go. I would think the gains are not huge over a correctly working distributor on near standard engines.

Is there actually any difference in cost between MegaJolt & Megasquirt?

They can also be configured to use your existing dizzy for base timing info and distributing the spark from the coil rather than having to install coil packs, TW, leads... as I mentioned earlier and particularly significant to the cost conscious amongst you.

[blitzracing]

spend said:

blitzracing said:

There is a system called Megajolt that is sold as a kit of parts for acround £400, (or about £250 if you build it yourself with second hand bits) that is fully mappable, but you are at about a third of the cost of replacing the whole ECU at this point so you have to consider if just replacing the ignition on its own is a good way to go. I would think the gains are not huge over a correctly working distributor on near standard engines.

Is there actually any difference in cost between MegaJolt & Megasquirt?

They can also be configured to use your existing dizzy for base timing info and distributing the spark from the coil rather than having to install coil packs, TW, leads... as I mentioned earlier and particularly significant to the cost conscious amongst you.

I doubt there a huge difference in the actual megasquirt / megajolt electronics price. I was taking a ball park figure against an Emerald system that seems to be the popular choise for the EFI side of things.

[GreenV8S]

blitzracing said:

I doubt there a huge difference in the actual megasquirt / megajolt electronics price. I was taking a ball park figure against an Emerald system that seems to be the popular choise for the EFI side of things.

I don't know if prices have changed in the meantime but my MegaSquirt came fully assembled for £320 a couple of years ago. I bought quite a few extra options such as a hardware simulator, extra drivers for water injection and knock control etc and with postage it came to about £350. Self-assembly would probably have halved that.