kwiksilverz

I figured I'd post this here since some of you guys are considering the APS F Body kit.

I just got around to getting my car on a dyno today. It is an 05 (LS2) GTO with a "slapped together in my garage with the block in the car" forged 9.4:1 shortblock with stock cam and heads. Only mods are the APS, boost a pump, alky (good amount of it!) and magnaflow cat back. The "peak" numbers are a touch higher than average due to the boost spiking then falling off when on the dyno, so it gets a quick peak before falling off.

This was done on a dynojet with std smoothing (what they prefer to use there for their own reasons).

Anyway- first run, right off the street in "as-is" state (how I drive it every day) was 713 hp, 719 tq. Run 2 was about 1-2 psi more and a little fuel tweak and it put down 743 hp, 746 tq. Another tweak on the MBC and it hit 768 hp, 761 tq.

Final run was a "bigger" tweak on the MBC and added a ton of fuel just in case it hit higher boost than anticipated and it pulled off 795 hp and 778 tq .

I know I could have easily hit 800 with just a little tweak of the MBC, but I was worried about how much more the stock pump and bucket would provide for, so I quit while I was ahead.

All the runs were 5-10 minutes apart, so there was no significant cool down time or any other cheats done to get the numbers better. If I could have gotten the boost to hold steady, it would have done better also- it was peaking about 19-20 and slowly settling around 15-16 or so. Also, I was tempted to drop the exhaust since I know that is killing this car, but again, I was nervous about too much more air flow with the stock pump so I just left it as it was.

Once I do the pump, I will be doing some more tuning, then taking it back and seeing what it is really capable of with open exhaust and such- should easily see 835ish at a minimum I would have to guess with the exhaust dropped and a bit more tweaking. Possibly higher if I can stop the boost from dropping off like this, which I think unbolting the exhaust will help a lot with.

Overall, this kit has been awesome- the quality is second to none and the performance is much more than I expected out of it. Simply amazing!!

I have attached a pic of the final dyno sheet. The AFR showed as lean as 12.0 on his WB, but never went higher than 11.8 on mine. It didn't knock, so I'm not concerned .

99Z28LS1

iTrader: (4)

those are some amazing numbers...... congrats

MY99TAWS6

iTrader: (3)

UMM>>>WOW JUST WOW!!
So you are on stock fuel pump..holy hanna..that boost a pump must actually work not bad. What about injectors..60 pounders..did you happen to check duty cycles..what fuel pressure stock or you have a reg?
So what does the car feel like on the street..lets have some more detailed opinions. Man I think I have a giant woodie now from reading this. Since I am going beyond with lingenfelter cam,patriot stage 3 heads ,fast 90/nw90, and likely 427 for sure 408.
So that pretty much proves easy 1000 hp or so engine and maybe even get close to that rear wheel with my planned combo? Wonder what max psi of the turbos would be. You could just pull the lines to the gates and see what they can do but woudlnt' be doing that on stock fuel pump! Wonder if they can do 25psi and if they would still pick up a bit more power.Course some spray would do wonders too. A small shot seems to have magnified effects on boosted cars. 1000 rwhp should be doable with likely only a 100 shot.

Lets here some street driving impressions on your bad boy!!

kwiksilverz

I am running Seimens 60# injectors. The stock pump with BAP is barely keeping up, but I am spraying a dual 15gph nozzle meth setup which is covering up for a lot of lost fuel right now until I get the fuel situated. The fuel system in the GTO is a returnless setup, so my pressure starts at 58 but I am afraid to put a gauge on it to see what it is dropping too from there lol, I just tun around it for now.

On the street, I am still running the stock tires and it is a handful to say the least- good roll on car, but only above 80 . Flooring it in 3rd at any speed will result in back pedaling and steering it through and last night, once it cooled off- 4th did the same thing . I'm going to pick up some DR's shortly for it though.

The turbos will be a bit out of there efficiency range at much past 20 or so and start generating more heat, but with alky, or especially nitrous, you will help take care of that and can make them work.

I'm not going to bother pulling the lines because I think the gates are actually being pushed open from exhaust pressure too. So I am just going to upgrade the springs and drop the exhaust before the next dyno run and probably take it to the track like that too. Just have to get the fuel situated first!

hellbents10

iTrader: (10)

Very impressive indeed!!!!

HUNTER02SS

iTrader: (24)

Nice #'s. How much boost? I did not see that anywhere.

kwiksilverz

"All the runs were 5-10 minutes apart, so there was no significant cool down time or any other cheats done to get the numbers better. If I could have gotten the boost to hold steady, it would have done better also- it was peaking about 19-20 and slowly settling around 15-16 or so."

I think the last run was actually holding about 17-18 or so, but I honestly wasn't watching the boost gauge on that run- I was glued to the WB since I spent no time tuning the car at that boost level, it was just crank the MBC, add a bunch of fuel and hope for the best .

BadMonkey

iTrader: (1)

Awesome numbers. Congrats on the Kit

MY99TAWS6

iTrader: (3)

Man oh man.with a bit more tweaking and you don't even have heads or cam yet. I am wondering what would expect to see on dyno then if did run a 427 with my fast90/90 and gt7 ling cam and stage 3 lq9 patriots..Should be another 100 hp up or just reach similar numbers at lower boost? Would think my power curve would shift lower and spool would be earlier. Do you get pretty much full spool at 4000? and do you feel it at mid 3500 range or a bit lower? Bigger engine should spool a bit quicker too. Not sure what effect a turbo cam will have. This kit sure seems to be performing great. Is the f body kit turbos exact same size as the gto turbos.? The vette kit think runs bigger ones?

Not that need anymore power than what you are getting. So 60 pounders can do the job but of course the meth is helping. So running 100% meth injection? and what about your timing can you share any detail on that?

eb02z06

iTrader: (18)

Very nice!!! Lets see some underhood pics!!! From what I have seen the APS kits are very clean and well done.

kwiksilverz

Lol, you're going to LOVE the underhood pics of my car- I went sleeper all the way down to keeping the stock air box in place . You'd never think it put down what it does by looking at it! The interior has just a boost gauge mounted in an autometer cup on top of the steering column and a wideband display hidden in the ashtray- very stealth looking. No one would ever think twice about running it .
Joe

kwiksilverz

And here's the car .
Joe
Edit- shoot, sorry the pics I have are two big. I'll have to get a resized pic for you.

Tiago

iTrader: (27)

why does the power drop off immediately after it peaks? stock valve springs?

I know you meantioned the boost was spiking, why woudln't it sustain?

kwiksilverz

No, I have upgraded springs. It was spiking boost by ~2 psi and then settling, which is why it had the little hump/peak like that, then the boost would drop as it came down from there which is why it tapered off so fast up top . It really has a lot to do with the combination of trying to run 7.5psi springs up to 20 psi using an MBC while having a restrictive exhaust pushing the gates open. It will get the spike because the MBC and gates are trying to hold, but they just can't. It also doesn't help much that I have about 6' of hose coming from my compressor housing to MBC and a 6' line from each of the MBC outlets to both gates- so it is going to spike just due to the hose length alone . I am going to try to re route how I have it plumbed and see if I can make it a bit more stable, but I feel it is a losing battle until I upgrade the springs in the gates and free up some exhaust flow.
Joe

kwiksilverz

I should add, it is also tough to keep the boost on with a no-load dyno, so that wasn't helping matters much either . It does hold much better on the street.
Joe

MY99TAWS6

iTrader: (3)

yeah likely help to go to higher gate springs so you don't have to use mbc to go up so much.I had to change spring in my talon from 14 to like 22 to get closer to 30 tops. You should just try a cutout on the exhaust. That should do good things and is cheap. So any idea of your timing ?

MY99TAWS6

iTrader: (3)

Oh what is your tuning program and are you still running maf or speed density.I thought maf coudn't do that type of power ?

kwiksilverz

Sine you are into DSM's- I'm Joe P. (the boost controller guy). Anyway, yeah, I need to go with 1 bar springs to try to get it to hold better, but I don't want to really go too crazy getting the boost to hold until I get a better fuel supply.

As for dumps, I thought that too- but I think I may actually just rotate the wastegates and block off the opening in the exhaust so that the gates dump to the atmosphere. This way I'll have my nice quiet car at cruise and such yet have the exhaust flow of a larger exhaust. Plus all hell will break loose when I lay into it .

As for tuning, I am using HP Tuners. It is not ideal to run a MAF this high, but I prefer MAF over speed density for day to day driving. I may go 2.5 bar speed density though so that I'll be able to tun for various boost levels and just turn the boost up and down as I want and the ECU will "see" it. Right now, if I tune at 16 and then turn it down to 10, the ECU still fuels for 16- just like if I get a spike, it goes a bit lean since the ECU doesn't see the extra boost either. It is working though .
Joe

cablebandit

iTrader: (37)

nice numbers. Please do not try a lot of load time on the street....the street load is way more than the dyno load and you will pop the motor when it goes lean since your fuel system is on the edge on the dyno.
Nice stealth.....tell em its got a tornado air insert

kwiksilverz

Oh, for sure. I turned the boost down before leaving . I am not going to push it hard on the street until I get my fueling resolved. I honestly didn't expect it to go as far as it did with what it has. I was hoping for mid 600's or so out of it with the stock pump, but it went further than i thought. Like I said, it was 713 on my first pull and that's how I drive it daily, so that's good enough for stock tires every day .

Thanks- it is very stealthy . Hmm, maybe I should call GMHTP and see if they'd be interested in doing a story on it .
Joe