engine and drivetrain More Power For My Rally Car...

[tomorrowcalling]

Using a dyno that reports greater results depends on whether he wants a real power increase or more bragging rights.

 

What I want is to get closer to the Pinto engined Escorts.  The BDA and Duratec powered ones however, are long gone.

[TobyB]

Hmmmm....

 

I dunno.  I'd be looking at the wideband trace next,

just because I'm that way.  But your curves are lumpy,

and with EFI, I'd wanna make sure the A/F wasn't...

 

Thinking back, 140 was on the engine dyno, so your 120 at the 

wheels isn't too far off what I saw- you might be getting towards

the limit of what you can get with that compression/cam combo.

 

hth,

 

t

[jimk]

Jim, you have some valid points but is the condescension really necessary?  We're all on the same team here.

His post was either a thread hijack or a brain fart because switching dynos has nothing to do with the assumption that the intake was limiting power.  Switching dynos for a bigger number is fishing for bragging rights, not imporving the power output, so I am not the bad guy it was the dyno switch comment that was not on topic.

Edited October 24, 2013 by jimk

[zinertia]

Colin

What size throttle body and inlet do you have?

 

I have gone to a 65mm throttle body and coresponding inlet piping to open up a bit.  (no results yet as it is not complete)

 

Also realize that the runners, box (what is it called?) and the throttle body are all a system and just changing one is likely not to make much difference unless it is from end to end.

 

 

Dennis

Edited October 24, 2013 by zinertia

[mossyboy6]

Thats a huge flat spot from 4500-5000rpm.

Edited October 24, 2013 by mossyboy6

[gracer]

The 304 cam should produce good power up to 7000 RPM providing you have the proper springs on the valves.  Your dynosheet stops at 5800 RPM.  Max HP should be ~ 6800 RPM.  G

[allbim]

I don't think your torque curve could be that lumpy just because the intake or exhaust are not optimized.  Something must be wrong with timing or the A/F ratio.  I'm not familiar with your ECU, but if you can do data logging you should do that and you won't even need a dyno for that. I would also take a look at the crank position sensor with a scope and make sure there is nothing erratic about the trigger signal. I did that once (on a lathe) before installation and found that the Hall sensor was not reliably able to resolve individual teeth on the trigger wheel. The good news is that there is great potential for improvement. Keep us informed.

[Rocan]

as others have said, two main things are off. Your tune isn't optimal judging by your dyno curves, and you are barely getting into the powerband of a 304. 

 

get us an AFR reading/ fuel table/ ignition map to look at first (data log is best!) and once confirming that all is correct, we can better help you get that little bit more (and I suspect it's hiding above 6 grand). also a 2" exhaust is definitely nearly at capacity by 6000rpm. 

[tomorrowcalling]

Thanks for everybody's comments,

 

So far my main take aways have been,

 

1    The car needs a better exhaust, is anybody aware of a supplier that makes headers for a RHD car.?

 

2    It needs to go back on the dyno.

 

3    Checking the ignition trigger is a good point,  I don't have a scope but I do have a very good timing light so I guess if I ran it up until  it was fully advanced and check to see if the marks are jumping around it will give me a bit of an indication if this is an issue.

 

Other comments.

 

Just because the dyno run stopped at 5800, doesn't mean I do. I rev it to about 7500 as it's definitely where the power is.

 

After discussing things with my co-driver / wife changing to carbs is still an option but it would be mainly so that we change classes.

Currently we have to run as a modified historic which buts us up against historic cars with modern engines, changing to carbs puts us back in the historic class.  (Plus I need to buy a set of carbs eventually for another project so even if I change back to fuel injection, the money is not wasted)

 

Putting aside any issues my car may have, I guess a more general question is,

 

Does fuel injection with a 318 manifold have more performance potential than a set of 45 DCOE's?

 

(I'm well aware that I've asked a "how long is a piece of string" type question and the answer is "it depends" but I'm interested to hear opinions)

Edited October 25, 2013 by tomorrowcalling

[scanner]

Hi, Jaymic do headers for RHD cars

http://www.jaymic.com/shop/parts_02_products.asp?grp=02EX&page=6

 

No idea how good they are but may be worth investigating? Seems expensive though, maybe getting a set made here could work out better? Sorry cant help with finding power - i doubt if mine is making more than 70hp at the moment ! Going with the webers must be tempting to be able to compete in a more appropriate class though. Cheers Chris

Edited October 25, 2013 by scanner

[TobyB]

 

Does fuel injection with a 318 manifold have more performance potential than a set of 45 DCOE's?

 

Yes, with everything else you've listed, particularly the 300 degree cam, unported head, etc.

 

No, if everything else is free, the 318 manifold eventually becomes a limit.

 

But changing classes to get in wiht like cars is always a winner...

 

t

[allbim]

tomorrowcalling, 

Lots of good info here.

http://77e21.info/mstunedintake.htm

[tomorrowcalling]

So it's been a while since I originally asked the question,

 

I built a set of headers for the car, for those that are interested it is a 4 into 1 with 1.5" equal length primaries  33" long into a 2.5" tail pipe.

 

It's a PITA to fit, I have to remove the steering column and steering box, however the car instantly went much better, particularly above  5000 rpm with the power continuing until we hit the rev limiter at 7500.

 

I haven't had it back on the dyno, there didn't seem much point as it went so well. We did however take 30 seconds off our stage time at one event.  Enough to go from an "also ran" to 2nd in class at that event and overall class winner for this years series.

 

Thanks for every bodies advice.

[TobyB]

Thanks for the update! 

 

One thing I found was that, after changing the exhaust,

rejetting the carbs usually found more power, too, as the

whole thing flowed better.  And in a different way.

 

So if you start to want even more, a return to the tuner

might find you some.

 

t

[tomorrowcalling]

So the numbers are in.....

 

After another dyno tune, 117 Hp at the wheels compared to 105 Hp before the new exhaust