[s346k]

Originally Posted by cmitchell17

Why did you buy both a LT2 and a MSD?

why not?

i didn't expect to get an LT2 so i bought an msd.

[cmitchell17]

Originally Posted by s346k

why not?

i didn't expect to get an LT2 so i bought an msd.

Oh ok, I want a MSD since I feel that is currently our best option without hood modifications, but they are just so unreasonably expensive and anytime I see one pop up used its instantly gone. My main goal is to try to get into porting and get some porting tools and try to make my own flow bench. I would love to be able to see the pressure drop tests for myself with my own eyes so I would no longer have doubts about what pieces work and what doesn't.

[s346k]

yeah doing everything ourselves would be ideal. unfortunately i'm not a speed shop, ya know. i should get some good 4th gear stuff this weekend. hope to try this dragy thing out, also. i made a couple 1/8 mi tests with it, but traction is scarce on the street and i had about 200 lb of extra weight in the car. still fun to play with.

[Trochoidal]

Originally Posted by s346k

....'m curious to see what the msd/95 combo does in comparison. still waiting on the msd to show up.

Are you still going to post the comparison of the LT1//LT2/MSD?

[s346k]

Originally Posted by Trochoidal

Are you still going to post the comparison of the LT1//LT2/MSD?

i probably should. but if we're being honest, at this point i have way too many unidentified logs and don't remember exactly. i can't make an apples to apples comparison of the manifolds as i swapped tbs, as well.

i do recall going over the logs and never seeing the car go above 95 kpa regardless of what combo was on it. i think the inherent design of the air intakes will almost always cause this.

with any luck i will have an over the radiator setup on the car in a couple of months. i really don't see the car going much faster with little things. it's a very basic setup that i feel is at its limit. honestly, i'm surprised it runs like it does given the weight and m6.

[Trochoidal]

Originally Posted by s346k

i probably should. but if we're being honest, at this point i have way too many unidentified logs and don't remember exactly. i can't make an apples to apples comparison of the manifolds as i swapped tbs, as well.

i do recall going over the logs and never seeing the car go above 95 kpa regardless of what combo was on it. i think the inherent design of the air intakes will almost always cause this.

with any luck i will have an over the radiator setup on the car in a couple of months. i really don't see the car going much faster with little things. it's a very basic setup that i feel is at its limit. honestly, i'm surprised it runs like it does given the weight and m6.

Ah those random log files accumulate fast. As much as we all try to give them names and dates, it’s inevitable to have get logs that no attention.

You’re right. At some point the setup is maxed out regardless of IM/TB combo. I know you’ve tried a lot and was hoping to see the final outcome.

As you mentioned in my other thread, OTR would be a great option.

Thanks for the update.

[vince3]

Originally Posted by Snowblind

Monitoring kpa is a thing and I watch it religiously. Their was a H/C car strapped to a dyno at my local shop, had a MSD and ported 87. I forget the numbers he put down but I saw his kpa was down to 94 (we are at sea level for reference) on a pull. I had the guys take my 95 off my car and swap it out while still on the dyno. 24 hp gain with no other changes.

If you are still active, I want to make sure I understand this correctly. They took off the ported 87mm tb, put on your stock 95mm tb and saw a 24 hp gain?

[vince3]

Originally Posted by s346k

made some pulls with a car i've ran before. the manifold definitely helped. appears to have picked up 1.5 maybe 2 mph. im very happy with it. i think using a 95 mm tb is the ticket to optimization. i think it would mitigate the kpa loss. i'm using a rock stock lt1 tb, i almost wish i had modified the intake to accept the 95.

lt2 im + lt5 tb is going to be the best bang for the buck, hands down.

the logs showed 48.5ish lb/min with the stock lt1 intake last week. lt2 showed 51.8 almost 52 today. i'm curious to see what the msd/95 combo does in comparison. still waiting on the msd to show up.

I came across this and wanted to share my best numbers so far. This is what my ported MSD and soler 95mm did at around 6400 rpm

Mass Airflow Sensor 8,908 Hz
Mass Airflow (SAE) 53.92 lb/min

[Mountain]

Originally Posted by s346k

i believe on NA motors it's widely accepted that one can consistently manipulate the map kpa with air intake modifications. ie if you see 100 kpa @ the start of a pull (2500 rpm) and 90 at the end (6500 rpm) there's a good chance you have a restriction, presuming the car has no other obvious issues.

my question is... is there an accepted horsepower value assigned to the kpa drop? i'm presuming it varies by engine and is a percentage based value.

i know it's not a one size fits all definition of scenario, but other cars i've had showing a drop like that really didn't gain much at all after correction. after comparing logs, my car now shows 96. im on the fence about a cai, as i am still using the stock one. it does very well with insulation and general function. the car picked ~67 whp / 73 wtq on the dyno with only a ported stock intake, full exhaust and e85. stock air box and stock tb still. the car runs hard, i hope to put a number on it at the track soon.

any of you guys with similar mods and rotofabs showing a similar kpa loss? i'm moving up to an msd/95 mm tb soon and don't want to leave 20 whp on the table by using the stock air box. but truth be told, i don't think there's much gain to be had at all with only bolt ons: rotofab vs stock.

fun fact: i saw kpa values as low as 93 before i cut the air box.

is this something anyone even looks at anymore on stockish cars?

Bain Racing has some fantastic [free] videos on youtube about engine airflow. In one of them, there is talk of a rough equivalence in air intake restriction based on a certain pressure drop/restriction. I can not recall at the moment though.