Horrible Dyno numbers and performance

Horrible Dyno numbers and performance

Author
Discussion

Etchhead

Original Poster:

24 posts

101 months

Monday 4th April 2016
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So I bought a used race car without testing so I expect a bit of this but was hoping for a bit more turnkey.

I've had my car out twice now and there aren't many knobs to adjust but I did swap fuel filter, air, plugs, FI cleaner and it still runs bad. The car has a fuel pressure regulator so I added fuel and it helped a bit bit it still acts up over 8000 and the Dyno results were horrible at only 108hp. The mechanic thinks I have an electrical issue. A coil harness had been placed and a few of the wires may have been touching. I'm trying to get replacement parts out of RadicalWest but not clear on what all I need.

Anyone else run into gremlins like this? Suggestions?

splitpin

2,740 posts

198 months

Monday 4th April 2016
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Presumably you've checked that the cylinder compressions are all OK?

Etchhead

Original Poster:

24 posts

101 months

Monday 4th April 2016
quotequote all
splitpin said:
Presumably you've checked that the cylinder compressions are all OK?
I've asked for the same but they didn't get to it yesterday. Hoping that can be done prior to the ignition parts swap just to make sure we aren't into a tired/worn engine. I'm told it has about 24 hours on it mostly DE. I've got the old EXU so not sure data can be pulled off...

Etchhead

Original Poster:

24 posts

101 months

Monday 4th April 2016
quotequote all
splitpin said:
Presumably you've checked that the cylinder compressions are all OK?
I've asked for the same but they didn't get to it yesterday. Hoping that can be done prior to the ignition parts swap just to make sure we aren't into a tired/worn engine. I'm told it has about 24 hours on it mostly DE. I've got the old EXU so not sure data can be pulled off...

Matt Graham

73 posts

194 months

Monday 4th April 2016
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I assume injected and not carbed. If it's carbed, sacrifice a chicken before running the car. Most reliable way I've found to make sure carbs run right.

If it's injected, have the injectors cleaned by someone that knows bike engine injectors (NOT a Diesel injector shop). I chased my backside for nearly 3 months one summer (10 years ago) trying to get a sick car to run right with dirty injectors. The extra time was due to the Diesel shop NOT cleaning out the little strainers on the top of the injectors (which apparently don't exist on Diesel injectors). Anyway, if it's a used race car, worthwhile to have the injectors cleaned anyway, then they are "known good" and you can proceed to log their time and know when to clean them again (every few years for me).

Also, what year and kind of car. I can probably help you source a spare set of injectors on this side of the pond.

-Matt

Etchhead

Original Poster:

24 posts

101 months

Thursday 7th April 2016
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Thanks Matt- mine is FI, although the chicken idea isn't a bad one! My mechanic received the coil, harness, wires today and will try to install then test tomorrow given time. Those fail his last options are O2 sensor and cleaning injectors.

Those all fail and I'll pick up car/trailer and tow back home (450miles) and look for close competent mechanic. Wish us luck!

BertBert

19,025 posts

211 months

Thursday 7th April 2016
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I guess you are over the water (as it were), but what about phoning Radical themselves and getting some ideas on how to diagnose. I know the car is quite old, but there might be someone there with a good memory of how it works!
Bert

Etchhead

Original Poster:

24 posts

101 months

Friday 8th April 2016
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BertBert said:
I guess you are over the water (as it were), but what about phoning Radical themselves and getting some ideas on how to diagnose. I know the car is quite old, but there might be someone there with a good memory of how it works!
Bert
Correct- I'm out in Oregon while car is down in California. I've been working with the RadicalWest guys out in Nevada and they have been going with suggestions above. Without getting the car to them or datalogs it's hard for them to get help more. They could get my car straightened out and that may very well be the next stop- but quite the tow (Portland to Las Vegas).

Etchhead

Original Poster:

24 posts

101 months

Sunday 10th April 2016
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FYI- replaced the Coil, wires and a spliced connector in that loom and it responded much better. Made 185 rwhp and freely revved I'm told (not 240 but much better than 108 and an older car 2006). Making a few tweaks to fuel pressure to optimize, but that sounds like the main issue.

Will be running it down at Laguna Seca Monday and I'll report back with how we did.
Thanks to all for the help-
Mark

splitpin

2,740 posts

198 months

Sunday 10th April 2016
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Good to hear. Not much wrong with that. Forget all those overly optimistic 240/250/260 figures, even if they are supposed to be crank plus a bit estimated for the magical (or is it mythical?) ram-air effect. A standard RPE K7 1475 in good 'right on the button' fettle (say recently refreshed but fully bedded in) gives say 185rwhp average, 190rwhp at best, a RPE K8 say just shy of 200 rwhp at best.


BertBert

19,025 posts

211 months

Monday 11th April 2016
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Made me wonder how much the transmission losses are different between the Quaiffe GDU and the good old chain drive. Anyone know? Just musing.
BErt