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Discussion Starter #1



Mitch Pederson happened to be in town right when my car needed a final tune. Build motor, stand alone AEM EMS, completely custom turbo setup, intercooler and Borla exhaust built by Joe Sims from TurboLab.

Unfortunately I'm running out of fuel capacity and can't boost higher, and by this run the car was fairly heat soaked hence the low HP. Earlier in the day we were getting 270-280ish at the wheels but the fuel map wasn't dialed in yet.

One minor detail. We were testing out a knock off chinese turbo, and well it blew it's seals.

Here it is blowing.


So next week Garret GT-28RS goes in, and then next year I'll redo the fuel system. And yes I know at some point I'm gonna have to redo the transmission. :)
 

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Yea that's a lot of torque for this little car. Definitely some potential there. Fix the fueling problem. The fuel system for a 93 octane car making (turbo powered) 400whp with an EMS is very simple and straight forward. A walbro 255 and some decent sized injectors (750cc+) would be more than sufficient. No need to even run a return if you don't want (although if you plan to track the car I would suggest a fuel starve solution).

Also the GT28rs will be a HUGE improvement. That turbo that's on there now really leaves a lot to be desired in terms of response. On the dyno it appears to be at full torque (i.e. likely full spool) around 5000 rpm.

The GT28rs will be full song around 3500ish I would guess. The transient throttle will also be much improved. The car will feel dramatically more responsive.
 

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Discussion Starter #3
That was my plan for the fuel system, thanks for confirming that it should work. I've just hit the limit of what my wife would like me to spend on the car this year. I am happier than I was though...prior to Mitch doing the tuning work I was making about 170# of torque and 260ish horsepower.

ETA: I'm at 4300 ASL here in Utah so that really screws with my ability to produce power.
 

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That was my plan for the fuel system, thanks for confirming that it should work. I've just hit the limit of what my wife would like me to spend on the car this year. I am happier than I was though...prior to Mitch doing the tuning work I was making about 170# of torque and 260ish horsepower.

ETA: I'm at 4300 ASL here in Utah so that really screws with my ability to produce power.
I understand the wife thing oh so well :eek:. And yea that is quite a big jump in torque from before the work.

Once the fueling is worked out and the GT28rs is on there, I'll bet the car is a totally different animal. It's going to be fun :)

Yea density hurts you at that level, although a turbo setup isn't hurt by it nearly as much as a naturally aspirated engine or a supercharged engine. The turbo wastegate regulates absolute boost pressure to be the same at sea level or in the mountains. The biggest difference being that the turbo needs to work a little harder (push more VOLUME of intake air) at higher altitudes to get that same boost level. Working harder does come at a little bit of a loss of power, but not as much as would be seen by the lower intake density of a naturally aspriated car for example. Also the dyno will automatically "correct" your numbers as though they were at sea level. So while the car may be faster at sea level the dyno results should stay roughly the same.
 

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Ya definently looks like the car is running out of breathe. Like a 50% loss of torque from 5K to 8K. I know you only mentioned ebay turbo, but I can't imagine what modern turbo could be smaller then a GT28. GT28 is the new T25 now-a-days. As small as people go.
 

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Discussion Starter #6
Ya definently looks like the car is running out of breathe. Like a 50% loss of torque from 5K to 8K. I know you only mentioned ebay turbo, but I can't imagine what modern turbo could be smaller then a GT28. GT28 is the new T25 now-a-days. As small as people go.
It's not an ebay turbo, it's a Chinese knock of GT28rs, which I guess could probably be found on ebay. It's the fuel it's running out of, though this run was also with the turbo blown, so it probably ran out of both.

The previous owner is the one who got the engine built, and turbo installed (I did the AEM) and he only went with 550cc injectors. Because of that I can't push it any more than about 14 pounds boost. Can't wait til next year when I can put the right sized fuel system in it.
 

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Any information/photos on the rest of the set-up (manifold, layout, intercooler, etc)? I have been pondering a GT28 based set-up for a while and am interested in what others are doing.
 

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Any information/photos on the rest of the set-up (manifold, layout, intercooler, etc)? I have been pondering a GT28 based set-up for a while and am interested in what others are doing.
Radium appears to have a nice kit over all if you are set on a turbo.

Lotus Turbo Hard Parts Kit

They sell the pieces individually as well.
 

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Radium appears to have a nice kit over all if you are set on a turbo.

Lotus Turbo Hard Parts Kit

They sell the pieces individually as well.
Yeah, I have seen that. I have access to local fab shops who are looking for work and are offering a deal on components.

I like Radium's cast manifold and downpipe and I may end up going that route. The engineer in me always wants to explore doing something myself first though (designing my own set-up)...
 

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Discussion Starter #10
I'll take some pics when were are putting the new turbo in. All if it is pretty much hand made and welded.
 

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For fueling issue. if you install BOE surge tank you get a 255 pump and fix two issues at once. That is what I did.
 

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Just a FYI- You can only get so much fuel through the stock pick-up in the tank regardless of the fuel pump you're running. There's a flow restricted ceiling somewhere around 310-350whp (inertia dyno) with the stock pick-up. We've modified the pickup, but it just doesn't make the needed difference. Need to look at an external pump setup like our surge tank or a totally custom pick-up to push past that...

Good luck,

Phil

edit: PS- Didn't see Lotus90's post. What he said!:D
 

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Discussion Starter #13 (Edited)
Agreed...and your surge tank is definitely something I am considering. :)

Oh I did have a question about it though if you don't mind. With your surge tank would I still need to replace the stock fuel rail in order to go to 700+ injectors? I would assume so just don't see any info about that on your site.
 
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