New to GT350 mani mod

[RSlo]

Looking through a bunch of positive experiences with 350 manifold and pulled the trigger tonight to order. Car is 2016 PP with Roush intake tuned for 105mm MAF diameter. 3" bassani catback exhaust. Still going to retain stock manifolds because haven't decided if in future if I'm going to do a procharger or twin turbo. Will install manifold and utilize stock throttle body. Still pretty green with tuning but was hoping to find direction in areas I may have to address in my tune before I install manifold. I'll try to list areas I think I may need to tweak.

MAF dial in
Plan on rev limits to 7500
Do I need any IMRC tweaks?
Do I need to mess with VCT to truly optimize
In current tune I have messed with DD tables for better seat of pants
Evntually put on dyno but do Torque/inverse tables need any massaging initially to run ok they are currently stock.

Thanks for all the feedback.

[Jn2]

If the MAF is calibrated now, it will continue to be that way with new manifold. You will need to correct the manifold volume though, pull the gt350 file from the repository and copy the changes for manifold volume. IMRC should work the same, VCT changes should be done on the dyno, leave them stock unless you are confident your changes will have a positive affect(even though it's hard to measure form seat of pants feel). Leave demand tables stock. Set your RPM to 7800 so you have some cushion and don't need to risk bouncing off the limiter.

[murfie]

I'm interested in your results of tuning this setup. Mainly the IMRC part. I believe the reason the 2015 + do not go into OP mapped point, is because the OP mapped point under IMRC configuration is missing.

[SultanHassanMasTuning]

you will def loose that SEAT feel with you swap the manifolds

[curt@injected]

I'm interested in your results of tuning this setup. Mainly the IMRC part. I believe the reason the 2015 + do not go into OP mapped point, is because the OP mapped point under IMRC configuration is missing.

The IMRC really isn't an issue on this swap.

[Plimmer]

If you are using the GT350 throttle body you will need to copy over those parameters. My setup uses the GT350 throttle body and you definitely need to fiddle with the IMRC settings to eliminate 90% of the part throttle surging.

When I first test drove my car with GT350 manifold and throttle body it surged badly on light throttle acceleration, then I adjusted the IMRC values to a blend of stock values and GT350 values and this eliminated 90% of the surging. It still surges slightly, but I can live with it and will fine tune it out one day.

[curt@injected]

Looking through a bunch of positive experiences with 350 manifold and pulled the trigger tonight to order. Car is 2016 PP with Roush intake tuned for 105mm MAF diameter. 3" bassani catback exhaust. Still going to retain stock manifolds because haven't decided if in future if I'm going to do a procharger or twin turbo. Will install manifold and utilize stock throttle body. Still pretty green with tuning but was hoping to find direction in areas I may have to address in my tune before I install manifold. I'll try to list areas I think I may need to tweak.

MAF dial in
Plan on rev limits to 7500
Do I need any IMRC tweaks?
Do I need to mess with VCT to truly optimize
In current tune I have messed with DD tables for better seat of pants
Evntually put on dyno but do Torque/inverse tables need any massaging initially to run ok they are currently stock.

Thanks for all the feedback.

I've actually done a few with the gt350 tb w/o issue. I have some stock gt350 tunes that could help.

Going against the grain here but that manifold doesn't actually gain nearly as much as people say. It actually sacrifices power all the way to about 6800. Most people are comparing a tuned gt350 manifold car to a stock tune 15. Here's a graph showing stock vs tuned vs gt350 on the same car. And yes I spent a ton of time on cam timing on both manifolds

gt350 vs stock manifold (1).jpg


Edit: Just realized that graph is standard corrected. Not that it really matters for the comparison but I don't typically use std #'s

[RSlo]

Thanks for all the suggestions. Almost second guessing myself at this point but seems there are quite a few people happy with the swap.

I guess another question would this manifold shine when adding some forced induction?

[GSLSE20B]

Thanks for all the suggestions. Almost second guessing myself at this point but seems there are quite a few people happy with the swap.

I guess another question would this manifold shine when adding some forced induction?

use the gt350 , you lose nothing below 6800 and gain a ton of torque to 7800 . you should also consider the throttle body . the gt350 throttle body is designed for increased velocity at low rpm over the gt throttle body . i gained a solid 1000 rpm of usable range over my gt manifold .

[curt@injected]

use the gt350 , you lose nothing below 6800 and gain a ton of torque to 7800 . you should also consider the throttle body . the gt350 throttle body is designed for increased velocity at low rpm over the gt throttle body . i gained a solid 1000 rpm of usable range over my gt manifold .

Yes you do

[AKDMB]

I've actually done a few with the gt350 tb w/o issue. I have some stock gt350 tunes that could help.

Going against the grain here but that manifold doesn't actually gain nearly as much as people say. It actually sacrifices power all the way to about 6800. Most people are comparing a tuned gt350 manifold car to a stock tune 15. Here's a graph showing stock vs tuned vs gt350 on the same car. And yes I spent a ton of time on cam timing on both manifolds

gt350 vs stock manifold (1).jpg


Edit: Just realized that graph is standard corrected. Not that it really matters for the comparison but I don't typically use std #'s

I knew it was way too good to be true. There is rarely a "magic bullet" bolt on part that carries power past peak and doesn't take away power down low.

[curt@injected]

I knew it was way too good to be true. There is rarely a "magic bullet" bolt on part that carries power past peak and doesn't take away power down low.

I mean I'm not set in stone on it. If someone were to show data demonstrating otherwise I'd be interested to see it. Most of the time when i try to tell someone what i found they tell me I'm wrong without providing data. They say another one of the big name tuners can do it better etc. I think we all know there isn't some kind of secret sauce tuning recipe on the coyotes. Cam timing + ignition timing + fueling = power. I spent a good bit of time on both manifolds and thats the result i came to. Plus my power numbers are not far off what any of the other big name guys accomplished.

I could show graphs that seem to demonstrate power gains all across the power band with the gt350 but it wouldn't be a true intake to intake comparison

[RSlo]

I've actually done a few with the gt350 tb w/o issue. I have some stock gt350 tunes that could help.

Going against the grain here but that manifold doesn't actually gain nearly as much as people say. It actually sacrifices power all the way to about 6800. Most people are comparing a tuned gt350 manifold car to a stock tune 15. Here's a graph showing stock vs tuned vs gt350 on the same car. And yes I spent a ton of time on cam timing on both manifolds

gt350 vs stock manifold (1).jpg


Edit: Just realized that graph is standard corrected. Not that it really matters for the comparison but I don't typically use std #'s

Was this your personal car or a customer? Even though some evidence of loss was he still happy with the performance of the GT350 manifold. Is that lower end difference so great that someone would change back to the stock manifold? Thanks.

[curt@injected]

Was this your personal car or a customer? Even though some evidence of loss was he still happy with the performance of the GT350 manifold. Is that lower end difference so great that someone would change back to the stock manifold? Thanks.

I believe this was the third we had done. The first two we were comparing to a stock baseline. I thought the cars ran pretty good.

This was the first that i had a true apples to apples comparison on. I spoke with the customer shortly afterward and swapped the intake and tune back free of charge. I/we didnt feel right charging him with the results.

[murfie]

The IMRC really isn't an issue on this swap.

I've actually done a few with the gt350 tb w/o issue. I have some stock gt350 tunes that could help.

Going against the grain here but that manifold doesn't actually gain nearly as much as people say. It actually sacrifices power all the way to about 6800. Most people are comparing a tuned gt350 manifold car to a stock tune 15. Here's a graph showing stock vs tuned vs gt350 on the same car. And yes I spent a ton of time on cam timing on both manifolds

gt350 vs stock manifold (1).jpg


Edit: Just realized that graph is standard corrected. Not that it really matters for the comparison but I don't typically use std #'s

Interesting observation that you don't need to change the imrc settings but you also say you don't retain power down low.

[RSlo]

Think I'm going to hold off on the intake for now. Am also curious if the opening and closing of the IMRC can be messed with to actually gain some of the low end torque back. Good discussions here. Really appreciate all the input here.

[RSlo]

Was doing some datalogging with the IMRC control sensor and it seems it is either closed(1.13V) or open(3.96V). Under IMRC wondering if you can tweek Optimum power of having the "Low RPM position" set "closed" and set the threshold to say 4500 or whatever. I would think that be an interesting dyno experiment for anyone with the 350 manifold.

[rshoe09]

even on most bolt on cars I do I set the threshold at 4000rpm, helps with midrange a bit

[RSlo]

Cool. Full bolt on like LTH, exhaust, CAI,? I only have catback and CAI. Any worth trying the threshold on my current setup? Was the midrange observed on a dyno or mostly seat of pants? Thanks.

[rshoe09]

Cool. Full bolt on like LTH, exhaust, CAI,? I only have catback and CAI. Any worth trying the threshold on my current setup? Was the midrange observed on a dyno or mostly seat of pants? Thanks.

I do it even on cars with just a cai, and yes this was dyno proven