Turbo charging a tbi 350

[0xDEADBEEF]

He also stated it would spool late, which means it spools even later on a 5.3. Maybe the 5.3s he's referring to spin up to 7000 and now that I'm paying more attention to the title, this is a TBI 5.7.

I think it's just the difference between a 200ish NA HP engine and a 300ish NA HP engine using the same size turbo.

 

[Supercharged111]

I think it's just the difference between a 200ish NA HP engine and a 300ish NA HP engine using the same size turbo.

Yeah, not that a 350 couldn't spool it, but one with no airflow would struggle. Although airflow south of 3000 RPM I don't know if even the TBI would give up that much if any to the 5.3?

 

[L31MaxExpress]

Yeah, not that a 350 couldn't spool it, but one with no airflow would struggle. Although airflow south of 3000 RPM I don't know if even the TBI would give up that much if any to the 5.3?

350 has its peak VE much lower in the RPM range and is larger. It should spool a turbo up much lower in the RPM range.

Then again when I had the Weiand 177 on my 350 TBI years ago it had INSTANT transmission destroying torque. It made 7 psi off-idle and peaked at 10-11 psi. With the stock heads and cam it came on like a light switch.

 

[RDF1]

Can you explain why an 88 would be good on a 5.3 but too big on a (larger) 5.7? Not being d i c k i s h, genuinely asking.

Doh! I left that one hanging big time.

The 5.3s are running TH400 with trans brake and leaving at 5500-6000 rpms on the 2step and shifting at 8500-8800 rpms and 35-40psi boost.

For a truck with a stock 5.7 it would take forever to get into boost. and when it did make boost you would need some big wastegates to regulate it down to 5psi.
If he would have mentioned a 60mm turbo then that would be perfect for lowish boost (5-8psi) and almost no lag. but then again what injectors and how would you tune a TBI for that?

 

[L31MaxExpress]

Doh! I left that one hanging big time.

The 5.3s are running TH400 with trans brake and leaving at 5500-6000 rpms on the 2step and shifting at 8500-8800 rpms and 35-40psi boost.

For a truck with a stock 5.7 it would take forever to get into boost. and when it did make boost you would need some big wastegates to regulate it down to 5psi.
If he would have mentioned a 60mm turbo then that would be perfect for lowish boost (5-8psi) and almost no lag. but then again what injectors and how would you tune a TBI for that?

i would use the stock injectors and a rising rate FMU like I did on the Weiand years ago. EBL Flash ECM board. At idle the fuel pressure was around 15 psi. At 10-11 PSI boost my fuel pressure was 50 psi. EBL coding has a correction table to allow for variable fuel pressure as well as a 2 bar map sensor.

 

[Supercharged111]

Doh! I left that one hanging big time.

The 5.3s are running TH400 with trans brake and leaving at 5500-6000 rpms on the 2step and shifting at 8500-8800 rpms and 35-40psi boost.

For a truck with a stock 5.7 it would take forever to get into boost. and when it did make boost you would need some big wastegates to regulate it down to 5psi.
If he would have mentioned a 60mm turbo then that would be perfect for lowish boost (5-8psi) and almost no lag. but then again what injectors and how would you tune a TBI for that?

So my 7000 RPM shift guess was coming up a smidge short. . .

 

[618 Syndicate]

Doh! I left that one hanging big time.

The 5.3s are running TH400 with trans brake and leaving at 5500-6000 rpms on the 2step and shifting at 8500-8800 rpms and 35-40psi boost.

For a truck with a stock 5.7 it would take forever to get into boost. and when it did make boost you would need some big wastegates to regulate it down to 5psi.
If he would have mentioned a 60mm turbo then that would be perfect for lowish boost (5-8psi) and almost no lag. but then again what injectors and how would you tune a TBI for that?

That makes sense, thanks for clarifying.

 

[RDF1]

i would use the stock injectors and a rising rate FMU like I did on the Weiand years ago. EBL Flash ECM board. At idle the fuel pressure was around 15 psi. At 10-11 PSI boost my fuel pressure was 50 psi. EBL coding has a correction table to allow for variable fuel pressure as well as a 2 bar map sensor.

Way over my head.. Ive thrown away so many tbi 350s its not funny.

 

[RDF1]

So my 7000 RPM shift guess was coming up a smidge short. . .

There is room for improvement. 5.3 at almost 9000 rpms sound sweet.

 

[RDF1]

That makes sense, thanks for clarifying.

I was in a rush the other day and didnt think to finish that one out.