supercharged 87GT hci advise

Rusty87GT

New Member
Aug 29, 2020
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hey guys, new to the forum and the foxbody world and would like to pick everyones brain on a set up i was planning to do and get some advise if it will work well or if i should go another route.

car is currently stock with the following engine upgrades:
a9l computer
maf with 19# injectors
bbk 255 fuel pump
flowmaster cat back
vortech v2supercharger
powerpipe with k&n fliter
vortech fmu
paxton fuel pressure regulator
.373 gears
130amp alternator
high torque mini starter
msd ignition coil
pro 5.0 shifter
upgraded control arms and suspension

what i want to do from here is the following:
trick flow twisted wedge heads (not yet aquired)
75mm throttle body (aquired)
gt40 upper and lower intake manifold (aquired)
- lower is ported to match a felpro 1250 gasket
- upper throttlebody opening is ported to 70mm
calibrated pro flow maf and 24# injectors (aquired)

will this work with the stock cam or do i need to upgrade?
i plan to upgrade the intake, injectors, cam and complete the exhaust later but these are the items i have available right now and im on a budget.
let me know your thoughts, thanks in advance.
 
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hey guys, new to the forum and the foxbody world and would like to pick everyones brain on a set up i was planning to do and get some advise if it will work well or if i should go another route.

car is currently stock with the following engine upgrades:
a9l computer
maf with 19# injectors
flowmaster cat back
vortech v2 supercharger
130amp alternator
high torque mini starter
msd ignition coil
pro 5.0 shifter
upgraded control arms and suspension

what i want to do from here is the following:
trick flow twisted wedge heads (not yet aquired)
75mm throttle body (aquired)
gt40 upper and lower intake manifold (aquired)
calibrated maf and 24# injectors (aquired)

will this work with the stock cam or do i need to upgrade?
i plan to upgrade the intake, injectors, cam and complete the exhaust later but these are the items i have available right now and im on a budget.
let me know your thoughts, thanks in advance.
anyone have any thoughts on this?
 
Those 24lb injectors are going to be a major handicap without a fmu to raise fuel pressure under boost.

Stock cam will work, but there are better options, especially if you’re doing heads and intake. Some long tubes always make power if you can swing those as well, even a good used set.

Also, by the time you mess around with maf upgrades, and find somebody competent enough to tune a stock eec, you’ve already spent the money required to do a standalone ecu such as a Holley or megasquirt. Having done all that before, I wish I went standalone from the get-go.
 
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Which of their heads are you planning on?

EDIT: I missed the supercharger. A stronger fuel pump and bigger injectors will be a good idea by the time you get to the bottom of the list.

Having Tmoss port the lower and matching the upper intake to the TB will help match the flow potential of the supercharger and heads.

It all should work with a stock cam.
But a cam to match the intake, heads, transmission. forced induction, gears, and intended use/power band will work much better. This could be a monster.
 
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I would agree with what 96pushrod wrote above. 24lb injectors won't be enough and you will want to run a larger fuel pump. With changing the heads and the cam you will be in need of having the car tuned and by the time you buy a maf and have the factory ecm tuned and then make any changes down the road you will be wishing you did a standalone right from the start, I did.

For reference, I previously ran stock heads, stock cam with a Trick Flow intake and a Vortech A-trim supercharger with a 255lph in tank pump, 36lb injectors, adjustable fuel pressure reg and calibrated MAF (no fmu). It ran surprisingly good and I drove it regularly on the street for two years including running it at the track twice. It was a stock A9L ecm with NO tune but I did have a wide band to monitor A/F ratio, timing was set conservatively, I had a btm box to pull timing with boost and ran on 94 octane. As i said though, that was stock heads and cam.

Over the winter I added Trick Flow 170cc twisted wedge heads, 1.6 roller rockers, new push rods and lifters and a TFS stage 1 cam.After the heads/cam swap it ran and drove around the block but air/fuel ratios were out to lunch and it was not what I would consider drivable and was in desperate need of a tune.

I ditched the factory harness and ecm for a Holley TerminatorX and upgraded to deka 60lb injectors and couldn't be happier with my choice. I had it running better than ever myself in short order and drove it for a couple months like that this year. I did have it dyne tuned recently but that was mostly just to dial it in and make sure it was safe at wot in boost and to get a number out of curiosity to see what it was making.

I was able to sell off my factory harness, A9L ecm, proM MAF and 36lb injectors for about half of what I paid for the TerminatorX kit.
 
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Those 24lb injectors are going to be a major handicap without a fmu to raise fuel pressure under boost.

Stock cam will work, but there are better options, especially if you’re doing heads and intake. Some long tubes always make power if you can swing those as well, even a good used set.

Also, by the time you mess around with maf upgrades, and find somebody competent enough to tune a stock eec, you’ve already spent the money required to do a standalone ecu such as a Holley or megasquirt. Having done all that before, I wish I went standalone from the get-go.
hey, thanks for the reply, i forgot to mention that i do have a vortech fmu and a paxton fuel pressure regulator. what is the benefit of a stand alone ecu opposed the an a9l?
 
Which of their heads are you planning on?

EDIT: I missed the supercharger. A stronger fuel pump and bigger injectors will be a good idea by the time you get to the bottom of the list.

Having Tmoss port the lower and matching the upper intake to the TB will help match the flow potential of the supercharger and heads.

It all should work with a stock cam.
But a cam to match the intake, heads, transmission. forced induction, gears, and intended use/power band will work much better. This could be a monster.
thanks for the reply! i am debating between the 170s and 190s, any suggestions? i guess i missed more than my vortech fmu and paxton fuel pressure regulator mentioned in my last response, i also have 373 gears and a 255 fuel pump.
 
I would agree with what 96pushrod wrote above. 24lb injectors won't be enough and you will want to run a larger fuel pump. With changing the heads and the cam you will be in need of having the car tuned and by the time you buy a maf and have the factory ecm tuned and then make any changes down the road you will be wishing you did a standalone right from the start, I did.

For reference, I previously ran stock heads, stock cam with a Trick Flow intake and a Vortech A-trim supercharger with a 255lph in tank pump, 36lb injectors, adjustable fuel pressure reg and calibrated MAF (no fmu). It ran surprisingly good and I drove it regularly on the street for two years including running it at the track twice. It was a stock A9L ecm with NO tune but I did have a wide band to monitor A/F ratio, timing was set conservatively, I had a btm box to pull timing with boost and ran on 94 octane. As i said though, that was stock heads and cam.

Over the winter I added Trick Flow 170cc twisted wedge heads, 1.6 roller rockers, new push rods and lifters and a TFS stage 1 cam.After the heads/cam swap it ran and drove around the block but air/fuel ratios were out to lunch and it was not what I would consider drivable and was in desperate need of a tune.

I ditched the factory harness and ecm for a Holley TerminatorX and upgraded to deka 60lb injectors and couldn't be happier with my choice. I had it running better than ever myself in short order and drove it for a couple months like that this year. I did have it dyne tuned recently but that was mostly just to dial it in and make sure it was safe at wot in boost and to get a number out of curiosity to see what it was making.

I was able to sell off my factory harness, A9L ecm, proM MAF and 36lb injectors for about half of what I paid for the TerminatorX kit.
awesome, thanks for the advice! out of curiosity how much did those set ups make on the dyno?
i am currently making 300hp to the wheels with my current set up.
 
hey, thanks for the reply, i forgot to mention that i do have a vortech fmu and a paxton fuel pressure regulator. what is the benefit of a stand alone ecu opposed the an a9l?
Ok, yeah the fmu will help with the smaller injectors. The stand-alone is more user friendly than tuning with the stock eec and chips, or quarterhorse. If you know how to work a laptop and read some pretty simple instructions you can get a cut running and tuned up.

As far as heads; it you’re buying a new set get the 190s.
 
Ok, yeah the fmu will help with the smaller injectors. The stand-alone is more user friendly than tuning with the stock eec and chips, or quarterhorse. If you know how to work a laptop and read some pretty simple instructions you can get a cut running and tuned up.

As far as heads; it you’re buying a new set get the 190s.
i appreciate your time and advice, thanks again.
 
also, do you think i will need a tune if i keep the stock cam?

Hard to tell. I'd get it tuned either way, it's leaving HP on the table not doing it. The big limitation on the stock ECU is that it doesn't like big injectors. I think you will be ok with the 255lph in tank pump as long as you go bigger on the injectors. It starts to squirm when you want to keep the fuel rail pressure high. I think I added an inline pump when I went over 85psi of fuel pressure. I'm still on a stock ECU though. I know after paying someone to tune it, you are halfway to the price of a stand alone, but then I would have to learn how to tune the standalone.

Kurt
 
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Hard to tell. I'd get it tuned either way, it's leaving HP on the table not doing it. The big limitation on the stock ECU is that it doesn't like big injectors. I think you will be ok with the 255lph in tank pump as long as you go bigger on the injectors. It starts to squirm when you want to keep the fuel rail pressure high. I think I added an inline pump when I went over 85psi of fuel pressure. I'm still on a stock ECU though. I know after paying someone to tune it, you are halfway to the price of a stand alone, but then I would have to learn how to tune the standalone.

Kurt
thanks for the response, i have never got a tune before, do they adjust timing, boost, fmu and fuel pressure as well as chip the ecu? or its just ecu related?
 
thanks for the response, i have never got a tune before, do they adjust timing, boost, fmu and fuel pressure as well as chip the ecu? or its just ecu related?

The ideal is to get rid of the FMU all together. It's a bandaid from back in the day. In the 90s when guys like me were getting into this, doing ECU tunes was something ricers did. Dinosaur V8 guys were still coming out of the carb age. NMRA even had a dedicated class for EFI guys who didn't do any ECU tuning.

A proper tune is done with the fuel pressure and base timing at least set close to stock settings. All adjustments are done through the ECU. All elements of your fuel system should be sized accordingly to the demand. That means you have the 30/36 lb/hr injectors, the right fuel pump, etc. That will make the car run better not only at peak power, but also in regular driving conditions. The FMU falls short in the transitions of full throttle and all other driving situations.

I don't have a whole lot of experience with blower setups. I'm running a nitrous setup where I spike the fuel pressure for correction. So I don't have the apples to apples information to be really helpful. For comparison though, I did put nearly 500hp/700tq to the wheels on a 255lph fuel pump and 30lb/hr injectors. I'm advising you against this approach for a blower car.

Kurt
 
The ideal is to get rid of the FMU all together. It's a bandaid from back in the day. In the 90s when guys like me were getting into this, doing ECU tunes was something ricers did. Dinosaur V8 guys were still coming out of the carb age. NMRA even had a dedicated class for EFI guys who didn't do any ECU tuning.

A proper tune is done with the fuel pressure and base timing at least set close to stock settings. All adjustments are done through the ECU. All elements of your fuel system should be sized accordingly to the demand. That means you have the 30/36 lb/hr injectors, the right fuel pump, etc. That will make the car run better not only at peak power, but also in regular driving conditions. The FMU falls short in the transitions of full throttle and all other driving situations.

I don't have a whole lot of experience with blower setups. I'm running a nitrous setup where I spike the fuel pressure for correction. So I don't have the apples to apples information to be really helpful. For comparison though, I did put nearly 500hp/700tq to the wheels on a 255lph fuel pump and 30lb/hr injectors. I'm advising you against this approach for a blower car.

Kurt
thanks again Kurt your feedback is greatly appreciated, i think based on everyones comments i need to revisit my injector size to 30 or 36lbs with my setup, i know somone with a similar set up running even higher injectors (46lb) but i think 36 would plenty on this setup as i am on a stock block and do not want to exceed 500hp to the wheels.