Mods Without Chips?

[Jotronic]

Just ordered a big 3" to 4" exhaust from Dave at LR for my 88 951 and I'm having Charlie work his Raptor magic on my turbo. But I then realized that my F9Tech DME may not be able to adjust for these modifications. Is this the case or should the DME adjust fine, albeit without being able to take full advantage of the new parts? I'm still heading down the stand alone ECU path soon, roughly, so should I wait or can I install these first and be ok?

[Tom]

Depends in part on what chips you are using and how much boost you run. Factory chips will trigger its so-called overboost protection if the amount of load/air flow into the motor exceeds its pre-set limit. If you have after-market chips, then the overboost protection is probably disabled, meaning you can continue to make power up to the limit of the airflow meter's ability to measure air (say, 300hp). If you start making that much or more, the car will start to go lean -- either because the injectors are max'd out and/or because the AFM is max'd out, or both. MAFs and big injectors help overcome these limits. Typical power upgrade path for that reason has been cat-delete and chips first, then MAF with boost controller, then turbo, then everything else....

[Jotronic]

Thanks, Tom. My F9 DME is running stock chips and the entire setup is stock save for my MBC. Yeah, I kind of realized after I posted that I'll probably need chips or a tune. My exhaust needs to go on soon as I recently discovered my muffler is rusted and the tip is about to fall off. I mean, if the muffler is having issues, it's time to order a 3" down pipe and a 4" exhaust, right? The turbo can wait to be installed but I'm assuming the new exhaust is ok with the stock DME, yes? I also spoke with Charlie and he said that it would indeed be recommended to get a tune with his turbo because it runs so much more efficiently than the stock unit.

Time to expedite my choice of stand alone ECU!

[Tom]

Have you considered starting with a good set of chips (e.g. Vitesse Racing), MBC, cat-delete, wideband, and the upgraded turbo. You might be shocked at how strong a 275 -300rwhp 951 feels. I actually think that's kind of the sweet spot for the chassis, and sticking with the factory engine management with VR chips means the car will retain factory smoothness 365 days of the year, morning, noon, and night (with a small fraction of the effort needed to install and tune a stand-alone). If you push beyond what, with stand-alone or otherwise, you have to start thinking about a new clutch, bigger injectors, stronger ignition, CV joints, etc., etc. I went down that road and don't regret it, but the car kind of takes on a perma-project status when you do....

Re the 4" exhaust, I'll just mention that my car made 500hp/500t on a dynojet using a 3" exhaust. Hard to imagine any functional benefit from a 4" exhaust, but it will make clearance and fitment more of a challenge. Just something to think about...

[JamesM]

I have old MAXHPKIT chips that I could make copies of if you want to try them. I got a raptor s and Charlie said the chips I have might work ok, they are for a lindsey 48. I haven't gotten a change to try them yet because my turbo project is a wip. I would be willing to make you copies with my eprom reader/programmer if you wanted to try them first. I am going to be running a adj fpr and a wideband which would be requirements to make sure these chips are working for Charlie's turbo. I got them for cheap enough that I thought it was worth the risk before I eventually try and go standalone.

[Jotronic]

Have you considered starting with a good set of chips (e.g. Vitesse Racing), MBC, cat-delete, wideband, and the upgraded turbo. You might be shocked at how strong a 275 -300rwhp 951 feels. I actually think that's kind of the sweet spot for the chassis, and sticking with the factory engine management with VR chips means the car will retain factory smoothness 365 days of the year, morning, noon, and night (with a small fraction of the effort needed to install and tune a stand-alone). If you push beyond what, with stand-alone or otherwise, you have to start thinking about a new clutch, bigger injectors, stronger ignition, CV joints, etc., etc. I went down that road and don't regret it, but the car kind of takes on a perma-project status when you do....

Re the 4" exhaust, I'll just mention that my car made 500hp/500t on a dynojet using a 3" exhaust. Hard to imagine any functional benefit from a 4" exhaust, but it will make clearance and fitment more of a challenge. Just something to think about...

I did consider chips when I first got my car in 2022, but moved on to thinking more about a stand alone now that I've got my suspension and brakes finished as well as vacuum and fuel lines upgraded. To be fair, I didn't look at chips very long because I decided I wanted to have options that I could add myself without having to rely on a new chip. And they never made a ton of sense to me since I don't see how a chip can be the most efficient manner of tuning a car when no two cars are the same even with having the same parts. I prefer the idea of being able to just slap in a chip and forget about it, but when I want to move up to more modern ignition options, I don't see chips being an option. I don't have super big HP ambitions, but definitely up to the 350 range so perhaps I should revisit that that option.

I did change my order today from a 4" to a 3" exhaust. I looked further into how it would fit and realized that they hang pretty low below the car based on one YT video I saw of an installation. If I change my mind, I can change out the back half as the 4" system isn't actually 4" at the front of the length. Thank you for your comments and questions.

[Jotronic]

I have old MAXHPKIT chips that I could make copies of if you want to try them. I got a raptor s and Charlie said the chips I have might work ok, they are for a lindsey 48. I haven't gotten a change to try them yet because my turbo project is a wip. I would be willing to make you copies with my eprom reader/programmer if you wanted to try them first. I am going to be running a adj fpr and a wideband which would be requirements to make sure these chips are working for Charlie's turbo. I got them for cheap enough that I thought it was worth the risk before I eventually try and go standalone.

That's very cool of you, James. Thank you. Seems like you have a similar outlook on this. I'm having an O2 bung welded onto the exhaust at LR before they ship it so I'll be adding a wideband, and I have an adjustable FPR ready to go in. Moving this to PMs.

[944m3]

I have the Raptor from Charlie and I hit overboost protection any time I build up speed. I always thought overboost would kick in during 2 or third gear. But I hit it in 5th gear all the time.

to take full advantage of upgraded turbo, I would say chips and 3bar fpr are a must.

[Tom]

Have you considered starting with a good set of chips (e.g. Vitesse Racing), MBC, cat-delete, wideband, and the upgraded turbo. You might be shocked at how strong a 275 -300rwhp 951 feels. I actually think that's kind of the sweet spot for the chassis, and sticking with the factory engine management with VR chips means the car will retain factory smoothness 365 days of the year, morning, noon, and night (with a small fraction of the effort needed to install and tune a stand-alone). If you push beyond what, with stand-alone or otherwise, you have to start thinking about a new clutch, bigger injectors, stronger ignition, CV joints, etc., etc. I went down that road and don't regret it, but the car kind of takes on a perma-project status when you do....

Re the 4" exhaust, I'll just mention that my car made 500hp/500t on a dynojet using a 3" exhaust. Hard to imagine any functional benefit from a 4" exhaust, but it will make clearance and fitment more of a challenge. Just something to think about...

I did consider chips when I first got my car in 2022, but moved on to thinking more about a stand alone now that I've got my suspension and brakes finished as well as vacuum and fuel lines upgraded. To be fair, I didn't look at chips very long because I decided I wanted to have options that I could add myself without having to rely on a new chip. And they never made a ton of sense to me since I don't see how a chip can be the most efficient manner of tuning a car when no two cars are the same even with having the same parts. I prefer the idea of being able to just slap in a chip and forget about it, but when I want to move up to more modern ignition options, I don't see chips being an option. I don't have super big HP ambitions, but definitely up to the 350 range so perhaps I should revisit that that option.

I did change my order today from a 4" to a 3" exhaust. I looked further into how it would fit and realized that they hang pretty low below the car based on one YT video I saw of an installation. If I change my mind, I can change out the back half as the 4" system isn't actually 4" at the front of the length. Thank you for your comments and questions.

350 is kind of no-mans land for these motors, imho. It's enough power that you need most of the typical upgrades (whether using the DME or a stand-along) such as injectors, clutch, turbo, wideband, boost controller, etc. Yet at 350, you can probably make more with those mods. You can get there either way with the DME or a stand-alone, but a lot less work/risks using the DME (unless you get help from someone like @chris white who has a proven system with lots of happy customers). If you are into setting up and tuning a stand-alone, absolutely go for it, but don't think you need to do that route to get to 350 (or even 450)hp...

[JamesM]

Motronic is pretty robust and stable, but for me I just can't justify buying new chips or a maf it when the cost of that is going to come close to what a standalone would cost. Particularly for 951s the harness gets really crispy too. Maintaining the original dme and klr has just gotten quite expensive and modifying it to run new sensors such as a maf and map and replacement chips cost lots of $$$. Also all the maps are available for download off of rouge tuning and I don't think it would be very difficult to port those over to a standalone for a pretty reliable setup. But most of all I am doing this because I enjoy tinkering so this will be a fun project after I get my car built.