6k Rev Limit

[Dolly racer 33]

What fuel pump do you have, what fuel pressure are you running. I would expect to see at least 170 BHP @ the wheels with your set up. When I first built 33 in 1988 I used Mahle pistons with a 10:1 CR,139 cam & 48's & got 190 Bhp @ 7,200 @ the wheels, I am now getting 195 @the same revs with the JE pistons. I have just built another Spint engine using a Group 1 thick wall block & have developed a new cam for it & am now getting over 200bhp @ 8,000 @ the wheels using 11.8:1cr. with no power drop off. I am trying to build upthe couragfe to take it to 8,500!!

31 deg advance is all you need. Obviously the lower the CR the more advance you can put in. I just use the Lumenition system in most of my cars from Rimmers or elsewere. It all fits neatly inside the distributor with no extra wiring needed.

[Mad Mart]

I'm using a Facet pump...



With Filter King regulator set to approx. 2.5-3 psi.

170 BHP at the wheels!!! I shall continue the quest for more power.

So I think now that the throttles open fully, I will tweak the ign timing & then take it to the rollers.

[paulsprint]

I would be tempted to take it to a differant rolling road. Someone with slot of experience with webers. Also take you laptop do you can adj the timing.

[Mad Mart]

I'm tempted to take it back to Interpro. Dave there seems to know what he's doing. Other than that I don't know of any other rollers nearby.

[zombeh]

I would take it here if it's got carbs on it.

[Mad Mart]

OK, new plan. I'm going to stick with my current setup until after my first track day of the season at Castle Combe next month.

I have just bought a set of Weber DCOE 48s. Next I shall invest in another new cam. Hopefully this time it will be the TT10106 equivelent from Newman cams...

Cam lift - 0.408"

Duration - 292 degs.

Inlet open - 40 degs. BTDC

Inlet close - 72 degs. ABDC

Exhaust open - 72 degs. BBDC

Exhaust close - 40 degs. ATDC

I have heard people say that 48s are too big for the Sprint engine. I have also heard it say that 45s are too small. Presumably with the correct cam, chokes & jets either will work fine? it just depends how much power you're after.

[SPRINTPARTS]

When I first built 33 in 1988 I used Mahle pistons with a 10:1 CR,139 cam & 48's & got 190 Bhp @ 7,200 @ the wheels, I am now getting 195 @the same revs with the JE pistons.

It must be the cold weather of the English dyno's, but no one have ever seen those sorts of figures in Australia!

Mark

[Dolly racer 33]

When I first built 33 in 1988 I used Mahle pistons with a 10:1 CR,139 cam & 48's & got 190 Bhp @ 7,200 @ the wheels, I am now getting 195 @the same revs with the JE pistons.

It must be the cold weather of the English dyno's, but no one have ever seen those sorts of figures in Australia!

Mark

I am getting more than that now!!

[soe8m]

When I first built 33 in 1988 I used Mahle pistons with a 10:1 CR,139 cam & 48's & got 190 Bhp @ 7,200 @ the wheels, I am now getting 195 @the same revs with the JE pistons.

It must be the cold weather of the English dyno's, but no one have ever seen those sorts of figures in Australia!

Mark

I am getting more than that now!!

Are we still talking about tuning engines or tuning dyno's

Jeroen

[Mad Mart]

I got my road tax yesterday so today I've been able to take the Sprint for a spin. First run was just to make sure things were running as they were when I took it off the road at the end of last year. Yep fine, with the same brick wall at 6250rpm. So then I remembered I'd set the rev limit to 6500rpm. So I came back home & adjusted the rev limit to 8000rpm on the Megajolt, just to make sure the limit was well clear of the engine's potential. Second run, no difference. . So I plugged in the Megajolt again & read the configuration from the EPROM. It hadn't changed, still showing 6500rpm rev limit. Eventually, after a bit of fiddling, I realised that I hadn't stored the new data on the EPROM. So I did that & set off on the third run. Sure enough it revved to 7000rpm. It didn't want to go any further though, that was it. At least I've solved that problem.

[paulsprint]

What a result ,Never thought of the rev limit. There is a setting for soft cut which is usally a few hundred rpm early than the hard cut. Soft cut usally retards the ING timing to 10 deg btdc.

[Mad Mart]

I'm using version 4.0.2, Paul. On the options tab under 'Additional Configurable Outputs' you have rpm limit for 'Shift Light' then 'Rev Limit'. I thought the shift light setting was just to send a signal for a dashboard light? would this be the 'soft cut' you mentioned? only that is set to 6000rpm at the mo.

[paulsprint]

No shift light is as it says a shift light. The output goes to ground at a per set point ( 6k in your case ) to earth a shift light bulb. The soft cut is setting on its own. When I've got the children to sleep I will fire up
The laptop and check where it is.

[paulsprint]

Mart, sorry got myself in a bit of a muddle between megajolt and megasquirt ING settings. Anyway megajolt has no hard cut rev limit ( as the edis unit it controls has not got this function) The megajolt rev limit retards the timing back to the limp home mode ie. 10 deg btdc. hence the reason the engine ran fine without missing just wouldn't pull any more.