Ls3 throttle body porting

[69 blue coupe]

Is it worth the money to have ls3 throttle body ported if so,who should I go to to get it ported.thanks Adrian

[Bsinclair]

nick williams is the go to guy on this.. most people see 4-5 hp gains.. worth it??? not unless your building a package you need to extract every bit of power out of.. in my opinion its not a very good investment.

[mikels]

Originally Posted by 69 blue coupe

Is it worth the money to have ls3 throttle body ported if so,who should I go to to get it ported.thanks Adrian

Have run stock 90mm and aftermarket 100mm TB on dyno with ZERO change in power (this on ~750HP LS7) with stock and FAST intakes.

So I have to vote, "save your money!"

[69 blue coupe]

Thanks guys,just the info I needed

[71RS/SS396]

For a roots style blower you will see a pretty good gain on a NA engine there's hardly if any gain.

[Matt@BOS]

Originally Posted by 71RS/SS396

For a roots style blower you will see a pretty good gain on a NA engine there's hardly if any gain.

Tim, I have a question, and you seem like the kind of guy who might know the answer. Do you think the smaller throttle body would provide better throttle response between idle and say, 3000 rpm?

Matt

[71RS/SS396]

Originally Posted by Matt.A

Tim, I have a question, and you seem like the kind of guy who might know the answer. Do you think the smaller throttle body would provide better throttle response between idle and say, 3000 rpm?

Matt

Matt, I think it would depend on the combination it was used on, but in theory I think it would help since a smaller hole will increase velocity.

[mikels]

Originally Posted by Matt.A

Tim, I have a question, and you seem like the kind of guy who might know the answer. Do you think the smaller throttle body would provide better throttle response between idle and say, 3000 rpm?

Matt

Response / Control / Power / Reliability - all must be considered

There is a few reasons we still build Stielow's supercharged engines with a stock 90mm TB:

1- Driveability - So much so that Mark is able to run autocross courses in 1st gear (with 815 Lb/ft TQ). Seemless control.

2- Power - Have yet to find a larger TB that increases power (with this combination). Total intake restriction is critical on supercharged applications, but we have found reworking the SC inlet (speaking about LS9 style Eaton 2300 TVS blowers), makes considerable diffference at these power levels (880HP in Mayhem). TB still seems to be smaller player in the power gain department. Induction tube is also critical - and we've been working on improving this area as well.

3- Reliability - Have had issues with all larger TB's tried with ETC faults and other issues. Maybe just down to bad luck with parts used, but can't win a race you can't finish.

Should also point out that have not seen appreciable (hardly even measureable) increase in power on stock LS9 with reworked inlet. Or TB change (stock LS9 is 89mm).

Always looking for power, but not willing to sacrifice driveability to get it.

Engineering the details - with data - is best way to make componant selection.

Bottom line - if 90mm is good for 880 SC HP (which is nearly 1000HP worth of fuel and airflow once adding in SC drive losses) - how much differnce can in make at lower power levels?

[PTAddict]

Based on what I've experienced, I agree with Mikels. I've seen no evidence that moving above 90mm on high performance LS motors yields statistically significant results. The same goes, BTW, for 78mm to 90mm for lower displacement (LS1) engines.

I've always been able to tune around the drivability and code issues with larger TBs, but the effort has never been worth it, IMO. Are you sure that the possibility of 3-4 HP more at the top end of the RPM range are really worth all of the expense and trouble? BTW, these experiences are not limited to LS motors - we've seen the same from Ford mod motors, for instance.