400 SBC Tbi conversion

[poppe78k25]

I've been toying with the idea of throwing a Tbi on my 400 lately. I have a 350 and a 454 version, the computers for both and the adapter plate for the intake. I was wondering if any of you guys had done this and if you had any advice for me on this setup. It's a 400 with ported 062 vortech heads assault racing intake 214/224 and 445/465 cam. Any words of advice would be awesome. Thanks guys!

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[LTZ C20]

A very important piece of information to check is the lobe separation angle of the cam. Fuel injection systems, especially with older, less adaptable systems, like the TBI, if the lobe separation isn't right, you will have issues creating the required vacuum reading from the MAP sensor at idle. It will cause drivability issues and you will spend a lot of time and possibly money to figure it out, thinking it's something with the newly installed TBI when really it's the cam.

This is exactly what happened to me with my last engine. I had no idea until someone else figured it out. I have a different engine now with a better cam with the right separation angle and I've never had a single issue.

In my opinion, if the angle isn't right, it's not worth the issues it will cause unless your willing to do the job of swapping in a new cam also. If I remember correctly, my old cam had a LSA of 112, my new cam is 110. That makes a huge difference in drivability. It's also worth mentioning, my new cam is more aggressive than my old cam.

[VileZambonie]

I've been toying with the idea of throwing a Tbi on my 400 lately. I have a 350 and a 454 version, the computers for both and the adapter plate for the intake. I was wondering if any of you guys had done this and if you had any advice for me on this setup. It's a 400 with ported 062 vortech heads assault racing intake 214/224 and 445/465 cam. Any words of advice would be awesome. Thanks guys!

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Definitely won't be happy with your current setup running a factory system and PROM. Are you talking aftermarket system?

[frotosride]

I've been toying with the idea of throwing a Tbi on my 400 lately. I have a 350 and a 454 version, the computers for both and the adapter plate for the intake. I was wondering if any of you guys had done this and if you had any advice for me on this setup. It's a 400 with ported 062 vortech heads assault racing intake 214/224 and 445/465 cam. Any words of advice would be awesome. Thanks guys!

Sent from my SM-G920P using Tapatalk

Definitely won't be happy with your current setup running a factory system and PROM. Are you talking aftermarket system?

Absolutely agree with this.... Unless it's aftermarket and you have that ability to program, you will be disappointed and frustrated trying to get it running right and actually making power if it's an OEM TBI

[poppe78k25]

I want to run the factory throttle body (either 350w/bigger injectors or the 454) I do realize I'd need to get the computer retuned. But I would imagine a big block throttle body would have the capacity to power a 400.

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[poppe78k25]

With the returned computer that is. I was just looking to see if anybody had done it and had any tricks or things they wished they would have done to help the process along

[VileZambonie]

What ECM are you going to use? That's where the dynamics happen. The factory TBI unit will work

[poppe78k25]

A very important piece of information to check is the lobe separation angle of the cam. Fuel injection systems, especially with older, less adaptable systems, like the TBI, if the lobe separation isn't right, you will have issues creating the required vacuum reading from the MAP sensor at idle. It will cause drivability issues and you will spend a lot of time and possibly money to figure it out, thinking it's something with the newly installed TBI when really it's the cam.

This is exactly what happened to me with my last engine. I had no idea until someone else figured it out. I have a different engine now with a better cam with the right separation angle and I've never had a single issue.

In my opinion, if the angle isn't right, it's not worth the issues it will cause unless your willing to do the job of swapping in a new cam also. If I remember correctly, my old cam had a LSA of 112, my new cam is 110. That makes a huge difference in drivability. It's also worth mentioning, my new cam is more aggressive than my old cam.

I would've never thought about that. I haven't actually ordered one but the one in my summit cart is a 112 LSA. I suppose I'll rethink that one. Thanks for the advice man!

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[poppe78k25]

What ECM are you going to use? That's where the dynamics happen. The factory TBI unit will work

It'll be the 454 TB, harness, and ECM and I'll just have to find someone that can retune that, correct?

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[LTZ C20]

I would've never thought about that. I haven't actually ordered one but the one in my summit cart is a 112 LSA. I suppose I'll rethink that one. Thanks for the advice man!

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The best thing to do is call Summit Tech line, tell them exactly what you want you want and what you have and what you plan to use and ask for a recommendation on a cam that will be good for that FI system. They will make a recommendation, then you can go online and look at the technical specs and see the LSA and lift and duration and then evaluate the situation to decide on the proper cam. That's what I did and I've delt with Summit Tech many times and they have never steered me wrong.

Another call to make is to Howell Engine Developments, ask to speak with person who does the PROM programming and can answer technical questions. I don't remember his name at the moment. Tell him what you have and what parts you plan to use and ask what recommendations he would make to have the system operate properly. The founder used to work for GM when they developed the TBI system. They know their stuff. They are located in Michigan, I think they open at 8 am tomorrow, CST.
Their number is (810)765-5100.

[poppe78k25]

I would've never thought about that. I haven't actually ordered one but the one in my summit cart is a 112 LSA. I suppose I'll rethink that one. Thanks for the advice man!

Sent from my SM-G920P using Tapatalk

The best thing to do is call Summit Tech line, tell them exactly what you want you want and what you have and what you plan to use and ask for a recommendation on a cam that will be good for that FI system. They will make a recommendation, then you can go online and look at the technical specs and see the LSA and lift and duration and then evaluate the situation to decide on the proper cam. That's what I did and I've delt with Summit Tech many times and they have never steered me wrong.

Another call to make is to Howell Engine Developments, ask to speak with person who does the PROM programming and can answer technical questions. I don't remember his name at the moment. Tell him what you have and what parts you plan to use and ask what recommendations he would make to have the system operate properly. The founder used to work for GM when they developed the TBI system. They know their stuff. They are located in Michigan, I think they open at 8 am tomorrow, CST.
Their number is (810)765-5100.

Wow, those guys at Howell sound like they know what they're doing. I'll have to give them a ring and see what they say. I didn't know summit had people that knowledgeable either.

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[LTZ C20]

Summit does yes, very much so. Howell yes they do, the programming guy has been there for a long time.

[poppe78k25]

Summit does yes, very much so. Howell yes they do, the programming guy has been there for a long time.

Sounds good. Thanks for the help LTZ!

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[LTZ C20]

Your very welcome.