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View Full Version : Installing S mod blower, what other mods should be done



mybirdcanfly
02-03-2008, 12:25 PM
Sorry I haven't had much luck on searches if you could please give me some rules of thumb on this installation.

With the S mod install, and assuming I might want to eventually go to 300hp but not more, can I live with stock fuel pump and injectors? Future mods would be exhaust (next) and MAF soon after.

Should I put in #38 injectors or is that if you go over 300hp?

I thought the stock fuel pump is good to close to 300hp but maybe I don't remember that right.

any comments greatly appreciated

mybirdcanfly
02-03-2008, 12:44 PM
XR7 Dave commented on thread " 95 injectors on 89 without tune?", that installation of #36 injectors from a 95 bird would work, the EEC will adapt but mileage would suffer.

I guess I could refine the question that as an everyday car I want the eventual hp to go to 275ish, not necessarily 300, try to keep gas mileage as good as possible under highway driving.

Is the change to #36 or #38 injectors required for this goal?...and what really drives the need for either the larger injectors and fuel pump? If I can get to 275ish without new injectors or fuel pump, upgrading eventually throttle body, MAF, and exhaust, then that's the way I'd go.

As the blower is coming off, I just want to get the injector thing over if that is important, and then get the car back on the road and drive it first, whatever is required to make that happen, then do the next set of mods later.

mybirdcanfly
02-03-2008, 01:08 PM
http://www.sccoa.com/forums/showthread.php?t=70401&page=2

this sounds like injectors might not be necessary,
by Kurt K:
"Yes Thomas, I ran a 13.54 @ 101 but do not have dyno numbers that Randy is looking for. This was only stock injectors and throttlebody, and rest of the old-school bolt-ons." (and I think this was a 1992)

also this thread by XR7 Dave, this sounds like approximately the car I want, just don't know if the injectors and fuel pump were required:
http://www.sccoa.com/forums/showthread.php?t=70401&page=4

"I do know that a stock 5spd car can easily run 100mph with the stock IC, no tune, and minimal bolt ons (I did it, with witnesses). According to my Hp calculator (which is junk btw ) that means 275rwhp. My mods were: Magnusen S-Port blower, MP inlet, C&L meter, UD pulleys, 5%OD, and gutted cats and resonator. I used pump gas, no alcohol, and no chip or tune. I ran on street tires with bad wheelspin and stock 2.73 gears (car weighs 3870 with me in it).

I do not have a CAI, ported exhaust manifolds, aftermarket downtubes, IC fan, raised top, bigger TB, or anything else. The motor has NOT been rebuilt and has been shown to be weeping antifreeze into the exhaust. It has 100K miles on it and it has never been dyno tuned or even changed plugs, wires or any sensors since I bought it."

mybirdcanfly
02-03-2008, 03:21 PM
this supports 36# injectors could be used without tune.
also found a few sites that said 36# are good to 300hp.
so that's couple rules of thumb i was looking for.
so if 36# is good to 300, I wonder if you could say the stock 30# is good to 250hp (250 +20% is about 300hp), assuming the 36# flows 20% more and horsepower is about proportional to fuel flow.

http://www.sccoa.com/forums/showthread.php?t=96462

"2. The computers in the cars have a limited ability to adapt to changes you have installed. For instance, you may get away with upgrading to 36 lb injectors and the later MAF and the computer can compensate and you shouldn't have that much if any issues. Go much bigger, to maximize performance and maintain regular drivability I would recommend a tune personally, but some folks seem to get by without one.... to a point ."

Kurt K
02-03-2008, 05:06 PM
http://www.sccoa.com/forums/showthread.php?t=70401&page=2

this sounds like injectors might not be necessary,
by Kurt K:
"Yes Thomas, I ran a 13.54 @ 101 but do not have dyno numbers that Randy is looking for. This was only stock injectors and throttlebody, and rest of the old-school bolt-ons." (and I think this was a 1992)

Since you quoted me, my 13.54 run was done on the stock 30 lb/hr injectors, but I also blew both head gaskets on that run and broke the ring lands on one piston. Additionally, it was colder than 50 F outside, which definitely helped.

I think it's a safe bet to upgrade your fuel pump, but if you are just upgrading your SC I think injectors and fuel pump are not required. Add more mods and then think about it.

fturner
02-03-2008, 05:40 PM
I guess its how much are you willing to spend to get there?

The usual recommendation I believe is that 42# injectors will safely support getting you to 300rwhp, a little less if your car is an auto. Don't go with the rule of thumbs out there for injector sizing as those are based on V8's not V6's which obviously require bigger injectors for the same amount of HP.

I would ALWAYS recommend upgrading the fuel pump. the stock one I believe is a 120lph pump, and its old and its tired. Get a 255lph HO pump and forget about it. All you would need is to have the hammer down going flat out and that old pump quite on you :eek: can we say bang.

My recommendation to you is to run 42# injectors, a matched up 73mm or 76mm C&L MAF and a 255 pump and you should be able to get to 300 with that. For optimal results get a chip-n-tune, but thats just my opinion ;).

I just wanted to add that running 42# injectors will net you 38#'s because the fuel rail is at 39psi, not the 43 or so the injector is rated at.

CMac89
02-03-2008, 06:22 PM
Stock injectors, regardless of the fuel pump, will not support anything passed 250rwhp (100% duty cycle). My 270rwhp with a 255FI pump and stock injectors saw a low of 12.5:1 AFR.

42lb injectors will get you around 330-350rwhp depending on if you use methanol injection or not. If you go that route, then you will need a tune and a MAF to go with it.

Yes, get the fuel pump.

David Neibert
02-04-2008, 12:02 AM
I guess its how much are you willing to spend to get there?

The usual recommendation I believe is that 42# injectors will safely support getting you to 300rwhp, a little less if your car is an auto. Don't go with the rule of thumbs out there for injector sizing as those are based on V8's not V6's which obviously require bigger injectors for the same amount of HP.

I would ALWAYS recommend upgrading the fuel pump. the stock one I believe is a 120lph pump, and its old and its tired. Get a 255lph HO pump and forget about it. All you would need is to have the hammer down going flat out and that old pump quite on you :eek: can we say bang.

My recommendation to you is to run 42# injectors, a matched up 73mm or 76mm C&L MAF and a 255 pump and you should be able to get to 300 with that. For optimal results get a chip-n-tune, but thats just my opinion ;).

I just wanted to add that running 42# injectors will net you 38#'s because the fuel rail is at 39psi, not the 43 or so the injector is rated at.

I agree...get 42# injectors and a 255 lph FI pump with a 76mm MAF.

David

Kurt K
02-04-2008, 12:16 PM
I agree...get 42# injectors and a 255 lph FI pump with a 76mm MAF.

DavidI wasn't discounting the fact that injectors and a fuel pump are in his future, I'm just not convinced they are needed for just upgrading from a stock SC to a S-model. I guess I am only answering the first question of the 3 that are in the first post.

David Neibert
02-04-2008, 02:00 PM
I wasn't discounting the fact that injectors and a fuel pump are in his future, I'm just not convinced they are needed for just upgrading from a stock SC to a S-model. I guess I am only answering the first question of the 3 that are in the first post.

I'm guessing that his stock 110 lph pump isn't going to provide enough flow at elevated boost levels, especially with the 30# injectors. I upgraded to 38# injectors and a 190 lph pump back when I was still running a stock early model blower and the car went .5 seconds quicker with no other changes.

What he has may work, but I think it will be cutting it too close for comfort. At a minimum I would upgrade to the 255 lph high pressure pump.

David

90MN12
02-04-2008, 02:47 PM
I guess its how much are you willing to spend to get there?

The usual recommendation I believe is that 42# injectors will safely support getting you to 300rwhp, a little less if your car is an auto. Don't go with the rule of thumbs out there for injector sizing as those are based on V8's not V6's which obviously require bigger injectors for the same amount of HP.

I would ALWAYS recommend upgrading the fuel pump. the stock one I believe is a 120lph pump, and its old and its tired. Get a 255lph HO pump and forget about it. All you would need is to have the hammer down going flat out and that old pump quite on you :eek: can we say bang.

My recommendation to you is to run 42# injectors, a matched up 73mm or 76mm C&L MAF and a 255 pump and you should be able to get to 300 with that. For optimal results get a chip-n-tune, but thats just my opinion ;).

I just wanted to add that running 42# injectors will net you 38#'s because the fuel rail is at 39psi, not the 43 or so the injector is rated at.

WAS WONDERING, SO IF I GOT 42'S OR 50'S WOULD IT HELP OUT OR NOT WITH THE STOCK FUEL RAIL BEING AT 39 PSI.

fturner
02-04-2008, 03:01 PM
If your going with an MP2 I'd say the minimum would be 42's at 39psi rail pressure. If your planning on using that MP2 to make more than 300rwhp, then go with the 50's.

Kurt K
02-04-2008, 03:13 PM
I'm guessing that his stock 110 lph pump isn't going to provide enough flow at elevated boost levels, especially with the 30# injectors. I upgraded to 38# injectors and a 190 lph pump back when I was still running a stock early model blower and the car went .5 seconds quicker with no other changes.

What he has my work, but I think it will be cutting it too close for comfort. At a minimum I would upgrade to the 255 lph high pressure pump.

David
After reading your post, it dawned on me that I did have a 190 lph at the time.

90MN12
02-04-2008, 03:13 PM
Let Me Tell You What I Have And Let You Advise Me On What To Get. I Have A 90 Anny Auto, Getting My Mp2 Rebuilt With Coated Rotors, 10% Od Sc Pulley, Ud Pulley's, Mp Top, Mp Plenum, 85mm Tb, 3.5 Cai With Filter, Going To Put In: 80mm Maf Out Of Mark 8, 2.5 Dual Exhaust Into Magnaflow Resonator Out 3.5 To A Flowmaster Super40, 255 Fuel Pump, Looking For Either 42's Or 5o's, And Possibly A Tuning Chip. Found Some Affordable 5o's Online. http://www.racetronix.com/17113738FM.html

David Neibert
02-04-2008, 04:11 PM
Let Me Tell You What I Have And Let You Advise Me On What To Get. I Have A 90 Anny Auto, Getting My Mp2 Rebuilt With Coated Rotors, 10% Od Sc Pulley, Ud Pulley's, Mp Top, Mp Plenum, 85mm Tb, 3.5 Cai With Filter, Going To Put In: 80mm Maf Out Of Mark 8, 2.5 Dual Exhaust Into Magnaflow Resonator Out 3.5 To A Flowmaster Super40, 255 Fuel Pump, Looking For Either 42's Or 5o's, And Possibly A Tuning Chip. Found Some Affordable 5o's Online. http://www.racetronix.com/17113738FM.html

Get the 50s....then you will still have enough fuel when you decide to do something with the cam and heads. Make sure you get the High Pressure/ Forced Induction 255 pump. The MAF you buy needs to be calibrated to the injectors and the EEC you are using....seriously doubt the Mrk8 meter is going to work without a special tune. You will need tuning and a chip to make it run correctly, even with a properly calibrated meter.

David

Ira R.
02-04-2008, 05:51 PM
Let Me Tell You What I Have And Let You Advise Me On What To Get. I Have A 90 Anny Auto, Getting My Mp2 Rebuilt With Coated Rotors, 10% Od Sc Pulley, Ud Pulley's, Mp Top, Mp Plenum, 85mm Tb, 3.5 Cai With Filter, Going To Put In: 80mm Maf Out Of Mark 8, 2.5 Dual Exhaust Into Magnaflow Resonator Out 3.5 To A Flowmaster Super40, 255 Fuel Pump, Looking For Either 42's Or 5o's, And Possibly A Tuning Chip. Found Some Affordable 5o's Online. http://www.racetronix.com/17113738FM.html

42's are the minimum you want to use I should think. Also, you are going to need to upgrade the IC in order to get any benefit from all of this stuff. A double IC should do nicely - possibly a front mount if you have loftier goals.

Ira

fturner
02-04-2008, 06:37 PM
Get the 50s....then you will still have enough fuel when you decide to do something with the cam and heads. Make sure you get the High Pressure/ Forced Induction 255 pump. The MAF you buy needs to be calibrated to the injectors and the EEC you are using....seriously doubt the Mrk8 meter is going to work without a special tune. You will need tuning and a chip to make it run correctly, even with a properly calibrated meter.

David

I agree, with that setup 50's would get you safe, and as David says... you will need a tune.

mybirdcanfly
02-04-2008, 07:11 PM
very nice, thanks for the comments.
I would surmise from these that you cannot hurt by going big on the injectors or fuel pump, that they "rise to the occasion" depending on other mods.
I suppose I was trying to get it running without a tune, hope to do exhaust and live with it for a while without having to put another $500 or so right away, having put out about $1500 on this and that so far.