This is My experience and what I'm doing. Just wanted to share the info I have collected for 8 months or so. Lot's of info here if not interested just warning pass it up. Do not want to change anyones mind just offering what I have learned.
Paragon and I as well as KenP have discussed this turbo stuff in PM several times.
I have been working and researching this since last fall well, started talking to STS last summer when this kit was posted on here the first time. I have to admit I'm a little disgruntled
due to the not going to do a H2 and have no plans I was told. I told the guy they sent me to do not worry I feel H2 customers are worth the effort and I'll find my own turbo system to run without STS on it. That was when I got off on to designing a twin kit.
STS does not recommend headers at all or they did not last winter when I was trying to get them to work with Me. Their additude has changed alot now and Jonahs had allot to do with that. I think they had more enguires as the year went on and Jonahs pushed them into doing what they should have done on there own along time ago. I tried to get them into a program deal that Jonahs worked out and they told Me not interested in H2's not enough business there. I told them if they would look at money spent per owner on stock vehicles a Hummer owner most likely top's the list and if not they have the desposible income to do it. I had a guy that they refered Me to since He had done allot of R@D for them and Pontiac putting an STS on a G6 and GTO for Pontiac. He tried to convince them the R@D was worth it and volunteered His labor if they would help and set an amount they wanted Me to spend. 2 months and We gave up and started on Our own. He is still is furnishing labor and R@D. He has a custom turbo builder helping Us. We are going to do a twin turbo similar for My personal use. I figured if I was going to do one just go twins as when i talked to the turbo shop he said He had already put STS on his wife's Suburban from a base kit when it first came out, had to go up in turbo size and pipe length. Runs great He said but, needs injectors and a few other things. He priced everything he thought it would take and I said I can have a SC for allot less, maybe not the perf.
We are using a different pipe coating and many other different things. We have tried several sizes and now are looking hard at some small turbo's that the rice rockets have been using to spool up quicker and found there mapping is over a broader RPM range than most of the turbo's recommended for a large block app. They have to be custom built as We are altering them from normal. This way We can have it spooled up before 2000 RPM and it will not lose top end boost like just jumping down in turbo size can do. You get into a give and take situation with the RPM range as many of Us have talked about in PM's. This is looking like it may help that alot.
STS said that headers would increase the exhaust flow to much and cause to much back pressure and a bottle kneck at the turbo. They are correct. you are trying to push exhaust trough a 1" hole versus what ever exhaust pipe size your using and that is if You are using the larger turbo's. The base kit hole is more like 3/4". They want the vehicle to be completely stock and it does not need to be more than that for their base system. I would have to chunck the $2000 in perf. mods to use STS. It works great. It is not unusual to get 100 Hp gain as well as a nice torque increase from the base kit. Jonahs should do better with the upgrades He is getting. Once You buy the base You pay for everything else on the side. Larger Inj., ADVANCE tuning, extra fuel pump, gauges, and so on. You can have $7000 in the system real quick if You want the very most perf. You can get out of it. If You change one thing on the kit youhave to go to the $500 tuning. They trade PCM tuned for stock equip. on the base kit. That is the number I was looking at if i did everything that could be added to base system. My man said for alot less We can do the twins by going to different vendors for different items. There is allot of upside to the base system. After We started R@D on the twins they checked back and He told them what We were doing and they would not support that either as they have made a blanket statement on their website saying that twins would not be helpful. I can understand that problem. We have found that with twins You can run header catback system and all the other perf. stuff You want as back pressure is relieved considerably. Twins We found will be very helpful when trying to move 7000 lbs. versus 4000lbs. (if that much) of an f body car for which the sytem was originally designed for. We shared allot of this info with them, so they may change their minds on twins as well, I hope so. They make it work for bigger engines and weight by using larger turbos and lengthening pipes depending on wheel base. I go every so often to check up and He does tests on another rig We have doing the R@D on. We do not use STS stuff as when We started even thinking about the single they would offer no support, so if I figured I had to be My own support I may as well use parts that will be warranted. I asked Him about twins and He said it most certainly is a viable idea and I'll provided free labor and research if You furnish parts. He then got a custom turbo builder to get involved and donate His time. We are using off the shelf parts so We can be sure of warranty once We get it to where it needs to be. That way if someone wants to do it the parts are easy to get. It is still a while before We get done and I will not sell it Myself to anyone but, I do not know what He is going to do. He is an independent shop that carries many brands of turbo systems and He may sell and install just for His clients. I may just give the specs to anyone who would like to do it. It is just something different and getting the heat out from under the hood is a great idea. STS is a very good company from everything I have read and heard. I would recommend them without hesitation. They have been very good to Jonahs and would be to anyone that is doing something they have. I believe without a doubt this Co. would stand behind there product once it is an off the shelf kit and they have done all the R@D to be sure it will function. Jonahs designed a great setup for gauge cluster that i recommend and I'm going to use.
Turbo's are universal and anyone can try what ever idea they want. Any of You that want a turbo do not even have to buy a kit. Go to a force induction shop and if you can imagine it they can try it. In fact We at the same time are messing with a sequential turbo set up to broaden the range of RPM to keep boost building or just maintaining it. That is a very interesting idea that the custom turbo guy got us into and there is a major car co. that will have a deisel with sequential coming out if it is not already, have not checked. So We are seeing if We can do something with it in gas.
Anyway if You have any questions PM me on what is happening if You have interest in the twin stuff and Jonahs has kept Me up to date on His system so He will be Our test subject on the STS. He is getting allot of feedback from STS.
He has all the latest info on it. We have kept check just to see if STS is doing anything different.
I will be putting on a SC by the end of April if I can get it painted and installed in that time frame. Alot has to do with Me getting the SC in time to finish the project by end of April. It is on it's way. We hope to have turbo finalised by the end of summer. It is allot slower than i had imagined but, the induction guy is very careful not to waste parts on a whim so I'm greatful for that. We are going very slowly and carefully to be sure We do it right and not build something quickly that will cause damage. We just do not want to do the project with a final install without very in depth testing. There are pluses and minus to both SC and turbo. What I have found is if You shop you can get a complete SC kit with intercooler, injectors, fuel pump, etc. for less than a turbo with all the same stuff. In fact as much as $2000 less.
But, I believe You will get absolutely better perf. out of a turbo. So it is just boiling down to what you like or are use to. I plan to build an offroader later maybe this year and put twins on it or put SC on it and twins on the Mall Queen.
Good luck Jonahs You the Man.
I hope You can get the discount as I told them last fall and winter if i helped with developement that I would like to get a discount for forum buddies and they did not care at that time. I hope they have changed. If You guys go with the base unit it will help allot but, if You start adding turbo's and other stuff which when I went to the guy they sent Me to He said the first thing was go up in turbo size, larger inf., extra fuel pump, etc.
I asked why, He said because your talking 7000 freakin pounds not 3500. You got to have a turbo that is going to spool up a little quicker. He said his experience is the kit turbo will start spooling good at 3000 RPM. Yes the H2 gets there guick he said but, by that time everybody else is gone. I ran numbers on My Girl with no forced induction and will run more using Gtech Pro and I'm showing 325 to 355 at the wheels avg. over 7 runs. I still do not know waht to make of it as talking to tech said trust it. I'm going to make a bunch of runs yet. But, the 0 to 60 is only 9.32 sec. slow to start then blast out at about 3000 RPM. Granted i have allot of mods. But, I wished it had more low end to get it rolling and it just will not roll quick enough. Agrivating but, I'm not going to the NHRA either.
Let us know how it goes Jonahs and the numbers when they dyno it. This could be some affordable power if they can make a kit at $3995.00 with the items specific for H2. It will be the way to go.
TAZ