injector size on ls with dsm turbo and a few other ??

[inthefastlane]

im gettin ready to do a motor swap into my 95 coupe and im going turbo . i need to know what size injectors should i go with ?? will 360's work ?? its a odb1 ls with a 97 talon turbo . im not planning on huge hp soon . id like to hit 300 to 350 by mid summer . probley going to do a ls/v turbo . planning on a minor head build up .

i also found a cast manifold with a flange for a external wastegate . i believe the turbo has a internal wastegate . now can you elimate a internal wastegate so i can have a external ?? or should i just find a manifold without the flange ??

since im here , what will it take to make 300-350hp without tons of boost and a stock block ??

ive heard that a lightweight flywheel shouldnt be used with boost , is this correct ??

 

[LS_VTEC]

To answer your flywheel question, the answer is yes. I preffered my 11lb.

 

[inthefastlane]

thanks , this is helpful . i was expecting to hear search !! i better shut up while im ahead .

 

[LS_VTEC]

Well, since you mention it. Go ahead and look around in the Reference Section. There's a lot of very good info there.

Stole his glory. lol.

 

[inthefastlane]

will 360 injectors work with on my setup ?? or should i go bigger so im not using the 360's to compacity

 

[inthefastlane]

i think he said they came out of a n/a 3000gt

 

[Briansol]

360's will get you to about 250whp ish.
turbo dsms are 450's

 

[amadeuscr]

I had 360 and it was not enough , I would recommend 450cc ! and a nice tunning

 

[DOHCtaDA9]

I recommend doing the math instead of guessing.

With what formula do you use to calculate this?

 

[amadeuscr]

pretty much

Pretty much !!!:

440cc up to 250whp
550cc 350-400whp
750cc 500whp
1000cc up are good for over 500whp

 

[DOHCtaDA9]

Does anyone know of anybody who has used a set of 2nd gen toyota supra 440's in their hondas? A buddy of mine has a set, as well as a set of DSMs, but he wont give me the DSMs!

 

[slammedvtec]

if i were you i would go big right away then you never have to upgrade, 750's will be plenty for 350 horse.

for the waste gate internal sucks, you can remove it and get the hole welded shut..

for 300 horse out of a stock ls i would say a decent sized turbo t3/t4 57 trim on 12 to 13 psi with arp head studs and cometic headgasket, and i nice tune by someone who knows what there doing.

as for the flywheel, they say the motor revs faster and slower down faster which make the turbo slow down at the same speed, but in reality i dont think it works like that but dont quote me on that one...

 

[inthefastlane]

thanks thats all i needed

 

[silver]

Bigger injectors than you need is a bad idea because you have to use them at such a low duty cycle.

Are you implicating there is a problem with that? Most DSM people over-compensate for injectors (up to 1150cc) since they are streetable. I've never had a problem with low IDC driving on my FIC1000's, however I realize this is a completely different platform so I'll yield to first hand experience.

Auto 1g DSMs had 390cc injectors, manual had 450's. All 2g DSMs have 450's stock.

By the math, 390cc injectors are good for 2.61 lbs/min of fuel, assuming pump gas and 43 psi base fuel pressure (what the injectors are rated at). 450's will do 3.01 lbs/min. Both of these numbers are at 100% IDC.

If you want to calculate based on tuned AFR, on a very conservative 11:1 tune you can support 28.7 lbs/min airflow and 33.1 lbs/min airflow, respectively. Depending on tuning and playing with BSFC numbers, you can get *up to* 10 whp per lb/min of fuel, but more realistically ~8 whp. With those numbers, the injectors will support 230 whp to 280 whp for the 390's, and 265 to 330 whp.

Please note that these are all theoretical numbers, and DO assume 100% IDC which is not that great idea. Thus, based on your goals, I would suggest....

550's or 650's and a bigger turbo--the T25 does not flow that much.

 

[philyphreak2127]

hold up the 3000gt's and talons do not come with the same turbo did he mean the injectors from the 3000gt? the te04h turbos from the 3000gt are junk to use on a single turbo setup. they only between 7-11 psi, however depending on the year and model of the talon the t25 and t28 are decent turbos. both rated somewhere near 25 psi

 

[silver]

hold up the 3000gt's and talons do not come with the same turbo did he mean the injectors from the 3000gt? the te04h turbos from the 3000gt are junk to use on a single turbo setup. they only between 7-11 psi, however depending on the year and model of the talon the t25 and t28 are decent turbos. both rated somewhere near 25 psi

No DSM ever came with a T28 stock. 1g manual cars had the TD05H 14B which flows significantly more, but will never see 25 psi. The T25 is laughably small and takes a shit above 15 psi.

50-80% is the range you want to use and 50% is pushing it.

Explain please, if you will. The only downfall I could see from having a low pulsewidth is possible poor atomization, which has not made a difference on my car at least (you never know how shitty the spray pattern is until you flow test your injectors).

 

[Turbo&Auto]

It will also take a total shit above 6K rpm.

 

[silver]

"Alright" results? Am I going to make less power by only having my injectors max out at 40% IDC? When the fuck did low IDCs become detrimental to making power? Great explanation and argument.

On the other hand, having smaller injectors and needing to upgrade just costs you money, but I suppose making your IDC fall within 50-80% takes precedence over that as well. If you can control larger injectors and forsee yourself wanting more later, what possible reason is there to go with smaller injectors?

 

[boostin4fun]

There is no need to guess what size injector you need. Go to this site and fill out the injector sizing worksheet and it will tell you... RC Fuel Injection