EntropyLS1

Hi guys, my car is a '98 Trans Am. This summer I'm going to have enough money to get myself a mild F.I. setup. I'm thinking about the single turbo "street" system from gmr speed. I assume I'll need new injectors and maybe even a new fuel pump, and I'd get a boost gauge, and boost controler. Is there anything else you think I'll need, spark plugs and an ignition amplifier maybe (is there even such a thing made for LS1's)?. My goal is around 400 whp on 93 octane. The reasoning behind my going for the gmr speed kit is it looks like I could upgrade it fairly easily for a lot of hp if i wish after I graduate and the T/A is no longer a daily driver. Is there another kit you guys would recommend? Thanks for the help

White.Lightning

iTrader: (53)

I recommend the D1sc from Bob at Exotic Performance Plus. Not that much money, easy to install/tune, can be boosted up to make tons of power. Call bob he will explain EVERYTHING for you ------> sponsor on right.

Good luck
Andy

BAD FNZ

400rwhp you can go cam only... but if you want boost then go with a D1SC procharger... A turbo setup is going to be alot more than a SC setup. The install is straight forward and pretty easy to tune. Unless you're looking to make more than 600rwhp then go with the turbo. but for 400-500 go with the SC setup.

Superman09

iTrader: (65)

I really dont think a mild turbo set up costs anymore than a S/C set up. Actually the STS and GMR kit are both cheaper to get running than the D1SC. I say right there are your three best options.... turbo.. GMR as you stated or STS, or D1SC if you want procharger.

98Z28MASS

iTrader: (6)

If your looking to make huge HP numbers down the road go turbo, if your going to want to stay around 500 rwhp then go with the ds1c. You will def need to upgrade your injectors (id say 42# injectors), plus a bigger fuel pump, and a real good tune.

smokinHawk

iTrader: (48)

me id rather get the turbo........

bboyferal

iTrader: (9)

Turbo wins!

LSs1Power

iTrader: (5)

A D-1SC can give u power from 400rwhp at 4psi to 750rwhp maxed out. You won't have lag... You will have a killer low end and topend (Midrange is better in a Turbo). You don't need to change the head unit when upgrading the engine later on.... Its easy to install and Tune. If you plan to run more than 11psi i suggest getting the SDCE setup.

Good luck

bboyferal

iTrader: (9)

Correct... BUT... Low end will be better on the turbo, too.

SS4Matt

iTrader: (4)

i am looking to FI very soon. and like i've said before.....if you're the kindof person who is not easily satisfied with speed (after a while, what you have just doesn't feel like anything anymore) i would suggest going turbo. there are a lot more options to upgrade down the road then with SC. just my $0.02 from everything i have read here...and i do a TON of lurking and reading!

Smearin

Welcome to the world of F.I

Be prepared to shell out the $$$$$$

LSs1Power

iTrader: (5)

Show me a Turbo car that makes a peak of 609rwtq and at 3000-3500 RPM makes over 500rwtq while holding over 500rwtq all the way to redline?

bboyferal

iTrader: (9)

Look up some dyno graph's of front mounts.

My peak torque on a Dynojet (no load) AND w/ 3.73's without full boost on the rollers is 470. It's over 400 from 3250 rpm until 5500 rpm. So with my turbo not working right, I get similar numbers and a similar torque curve with a weak-*** boost response (5-6 psi?). I hit 8-9 psi on the street at 3100 rpm. Anyone who knows about turbo's knows that with 9 psi at that low of an rpm, I should have about 570 rwtq and over 500 from 3k rpm until redline, too... WITH ONLY 500 ~rwhp... Hmmm... Why a higher TORQUE number than HORSEPOWER? Maybe the low end?

If I made over 600 rwhp peak, my torque peak would be about 700 and be over 600 from 3k rpm until redline. What do you think full boost at redline vs. full boost at 3k rpm will do? Come on... Also, why do you think ALL frontmount turbo's make MUCH more rwtq vs. rwhp... While the opposite is true for centrifugal superchargers?

MAYBE the blower motor has to be wound up higher for peak power? Of course low end will be better on turbo's.

Show me a Procharged/Vortech car that makes 100-200 more tq than rwhp...

Powerband... Fastest LS1 built by W2W: Twin Turbo... Fastest LT1 with a custom PTS set-up: Turbo. Loading the boost is tricky, but a properly sized turbo WILL ALWAYS make more low AND mid-range power than a centrifugal supercharger.

EDIT: Keep in mind, the turbo's numbers will be negatively skewed on any dyno anyway while the blower spins away and doesn't know if it's on a dyno or the street... And you COULD STILL see the difference in powerband... And the turbo will STILL have higher tq. numbers = more low end.

bboyferal

iTrader: (9)

Peaky/High powerbands: max-effort NA, small displacement motors, max-effort centrifugal blowers, over-sized turbo's, etc. <MORE RWHP THAN RWTQ>

Balanced powerbands: centifugal blowers, max-effort Roots blowers, slightly over-sized single turbo's, Street cam NA, most twin turbo's, etc. <SIMILAR TQ and HP>

BIG area powerbands: Twin Screw blowers (proper application), Big displacement and street NA, nitrous, Roots blowers (efficient app's), most single turbo's (properly-sized), many twin turbo's, etc. <MORE RWTQ THAN RWHP>

My opinion of course, loose estimation, for the sake of a rough, proportional observation with some possible mistakes.

AND this doesn't mean anything anyway because ANY powerband can run fast... Look at the fastest Supra's in the 8's on DR's. They have very peaky powerbands... But the low end for LSX's... Turbo for the win.

LSs1Power

iTrader: (5)

Similar numbers to what exactly... LOL... When you have higher peak TQ number than HP that doesn't mean you have a better low end. Low end power means which will produce more power between 2500-4000RPM. Thats low end. Midrange comes between 4000-5500 and topend starts after that until 7K or so.

Believe me i have looked at tons of dyno sheets its not even funny. When a turbo produces great low end power it will most likely run out steam around 5500rpm because its sized to work in that range. If the turbo gave great topend it will most likely suffer down low. I said midrange because usually turbos make great power in the midrange no matter what they are sized for because by that time they are already spooled. The nice thing about a SC it performs well in all ranges.

I really dont want to get into Turbo VS SC discussion now, but thats what i have seen in my experince with Turbo and SC'd cars.

If im going with a drag car setup i will most likely go with a huge single turbo plus Nitrous for spool up just because there is nothing like a huge turbo performance in midrange and topend which is what you need in a drag race.

bboyferal

iTrader: (9)

EXACTLY... I agree... so potentially, you could size a turbo to beat anything on the low end (dropping a bit up top, I know)... OR... You could size a turbo to beat anything on the top end (but suffer in the low, I know)... OR you could properly size a turbo, cid vs. turbo size, to slam hard and peak in the middle and have MINIMAL drop-off up top and MINIMAL lag down low...

The BETTER LOW/midrange END is WHY the TQ #'s are HIGHER than HP for MANY turbo set-ups...

Centri SC's: The better rwhp than tq is why the centrifugal blowers have mid to high on the powerband as the better area... They are wound up higher... their power is higher...

You may be right, but I would like someone to address this accordingly.

LSs1Power

iTrader: (5)

Again higher peak TQ than peak HP doesn't mean the setup has a better low end.
Its true that Centri SC are peaky in nature which is why their midrange is most likely lower than a Turbo. The reason they are peaky are because they start with a faily large amount of boost from 1500RPM for example in my case i see 10psi at 2000 RPM, but then it starts building boost slowly until redline 13psi and hold it. That is why it make more power down low and then hold great power on the top end because with a SC there is no boost drop unlike most turbo kits when they face increasing backpressure and tend to drop few psi before the redline (That also depends on the size of the turbo).

bboyferal

iTrader: (9)

So... your peak boost is 13 psi? And you make 10 psi at 2k rpm? With a Procharger/Vortech?

Just askin'...

Oh, and...

I don't know about that...

LSs1Power

iTrader: (5)

D-1SC

You can check the dyno sheet your self and you can see the Boost log on it. The dyno shows 11.7 psi at 3600RPM and a max of 13.6psi at 6K RPM.

The same thing happend when i had the SC pullied for 8psi before.... I used to see 5psi on 2000 RPM and then it starts climbing until 8psi. With that i used to get 400rwtq at 3K RPM and 500rwtq at 4200RPM on a Dynojet. If you want to see that dyno sheet i have it somewhere too

EntropyLS1

well I really didn't want this to turn into a SC vs Turbo thread as I'm sure there are a plethora already. Thanks for the info though. And yes I will be going with the turbo because my plans are to upgrade later for around 750ish hp. Plus I really like turbo noises!