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Re: 2.8L N/A 318hp Build Recipe
Posted: Wed Jul 03, 2024 5:58 pm
by michaelmount123
Ish_944 wrote: Wed Jul 03, 2024 3:21 pm
Hi Michael,
Thank you so much for sharing your wisdom regarding these engines!
I'd also like to get your opinion and advice, if I may!
I had built a 2.85l stroker starting with a 2.5l block and a 3l crank, Pauter lighweight (for NA) rods, Chevy 4" pistons. The block was dry-sleeved and obviously bored to 4". CR is 10.9:1.
The engine has valve springs & injectors from the Turbo, a 'Road-Race' cam from Augment Automotive (from the UK), as well as their standalone ECU (which runs on IAT & MAP).
The rest of it is all stock.
My main goal with the build was to increase low-down torque, since the car is mostly street-driven.
Here is the dyno graph that it produced.
My questions are:
1. What are your observations of the dyno sheet? Does anything stand out to you?
2. Do you have any recommendations how to further improve it?
Thank you very much in advance! Your insight is very much appreciated!
I built an identical 2.5NA engine with a 3L crank, stock cams, stock exhaust, stock intake, some headwork, and a custom chip. It made around 215fwhp. I'll bet yours could be improved with proper cylinder head porting and reworking the stock Motronic chip to maximize power. The stock chip can't take advantage of the mods you've done. Put it back on the dyno with someone who can adjust A/F ratio and timing and produce a custom chip. If you're here in the US, perhaps send me your head for upgrades, but it will still need proper tuning via a custom chip.
Cheers,
MM
Re: 2.8L N/A 318hp Build Recipe
Posted: Thu Jul 04, 2024 2:48 am
by Ish_944
Thanks for the suggestions!
As I mentioned, I do have a standalone ECU, so no Motronic and no barn-door afm on this engine.
The engine was actually live mapped by the manufacturer of the ECU, Tom Barker from Augment Automotive.
Would you be willing to do a head for me even if I'm from Europe?
My medium-term plan is
* Head work
* ITB kit (I'm eyeing the one being developed over at RL)
* Racer's edge header after reading through this thread.
I'd like gain a bit of top end power without sacraficing torque between 2-4k rpm. I'd also like to have it rev a bit more freely and quickly.
Intentionally did not mention them because I wanted your opinion without any upfront bias.
What rod to stroke ratio would you recommend?
Re: 2.8L N/A 318hp Build Recipe
Posted: Thu Jul 04, 2024 6:29 am
by chris white
I would play around with the cam timing. the torque curve is rolling off too early.
Re: 2.8L N/A 318hp Build Recipe
Posted: Thu Jul 04, 2024 8:57 am
by blade7
Ish_944 wrote: Thu Jul 04, 2024 2:48 am
Thanks for the suggestions!
As I mentioned, I do have a standalone ECU, so no Motronic and no barn-door afm on this engine.
The engine was actually live mapped by the manufacturer of the ECU, Tom Barker from Augment Automotive.
Manufacturer of the chip board live maps the engine, how many hours was it on his rolling road?
Re: 2.8L N/A 318hp Build Recipe
Posted: Thu Jul 04, 2024 11:17 am
by michaelmount123
Ish_944 wrote: Thu Jul 04, 2024 2:48 am
Thanks for the suggestions!
As I mentioned, I do have a standalone ECU, so no Motronic and no barn-door afm on this engine.
The engine was actually live mapped by the manufacturer of the ECU, Tom Barker from Augment Automotive.
Would you be willing to do a head for me even if I'm from Europe?
My medium-term plan is
* Head work
* ITB kit (I'm eyeing the one being developed over at RL)
* Racer's edge header after reading through this thread.
I'd like gain a bit of top end power without sacraficing torque between 2-4k rpm. I'd also like to have it rev a bit more freely and quickly.
Intentionally did not mention them because I wanted your opinion without any upfront bias.
What rod to stroke ratio would you recommend?
Yes, I can do a head for you as long as you handle the shipping both ways.
I wouldn't change the connecting rod length. Use the Molnar rods you have.
MM
Re: 2.8L N/A 318hp Build Recipe
Posted: Thu Jul 04, 2024 12:51 pm
by Ish_944
blade7 wrote: Thu Jul 04, 2024 8:57 am
Manufacturer of the chip board live maps the engine, how many hours was it on his rolling road?
Took him about 3 hours, but the car had been running decently even before that.
Re: 2.8L N/A 318hp Build Recipe
Posted: Thu Jul 04, 2024 1:39 pm
by blade7
It's always seemed like quite an expensive option.
Re: 2.8L N/A 318hp Build Recipe
Posted: Thu Jul 04, 2024 2:09 pm
by SirLapsalot
I’m not familiar with that ECU and its capabilities compared to other current ECUs, but 3hrs is an insanely minimal amount of time to calibrate an engine on a dyno from scratch.
Re: 2.8L N/A 318hp Build Recipe
Posted: Thu Jul 04, 2024 2:37 pm
by chris white
Tuning for peak power is the easy part. Throttle response and part throttle tuning is best done on the street. The last 20% takes 80% of the time!!!
Re: 2.8L N/A 318hp Build Recipe
Posted: Thu Jul 04, 2024 2:38 pm
by Ish_944
SirLapsalot wrote: Thu Jul 04, 2024 2:09 pm
I’m not familiar with that ECU and its capabilities compared to other current ECUs, but 3hrs is an insanely minimal amount of time to calibrate an engine on a dyno from scratch.
From scratch, yes.
But he has done dozens of 2.5, 2.7 & 3.0l, hence has good base maps and experience. In fact, my engine ran so well on the base map that I crossed Europe without issues just to get to him. So this was only fine-tuning.
Chris's recommendation about cam advance seems like a great one, exactly the type of insight I posted for in the first place! Thank you very much!