Chris, does the hotside on your GT25 have an integral wastegate? By the looks of your last photo, the flange on the hotside looks like a standard 4 bolt setup.

The reason I ask is cause all the GT25 turbos I've seen use an internal wastegate on the hotside. Even the GT25's I've seen at Technodyne used an internal wastegate. Curious...

If you are interested in a V-band adapter plate option check this out: (if you've got the wastegate option)
http://www.atpturbo.com/Merchant2/me...egory_Code=FLS

Chris, it's great to see dyno results that were done at very common boost level and with pump gas. Looking good man!

BTW, the Ray Hall Turbocharging site has a turbo calculator link and it recommends a GT25 for displacements between 2.4-2.6L with boost setting up to 20-22 lbs @ 6400 RPM. Check it out.

http://www.turbofast.com.au/TFmatch.html

Keep us posted Chris

 

Vic, can you send me an e-mail? I've got some projects I'm working on that I'd like to discuss.

Sam

 

[QUOTE]Originally posted by Pauerman
[B].

"The reason I ask is cause all the GT25 turbos I've seen use an internal wastegate on the hotside. Even the GT25's I've seen at Technodyne used an internal wastegate. Curious..."

What kind of GT 25? Garrett? Not all are internally wastegated, there are some that are external. They are difficult to get but it's possible. We avoid using internal wastegates. They create turbulance at the outlet of the turbine and slow down flow. A good external wastegate will make better power every time.

BTW this is NOT a GT 25 turbo. Not even close.

I will keep you posted. Thanks.

 

Pauerman

The "turbo calculator" on that link is off (not accurate)..

Not even close.


The guy that wrote that script needs to go back to Algebra 2.

TonyG

 

Chris,

With all the comments on this thread about the GT 25 I got caught up on assuming your turbo was a GT 25 - sorry.

After looking through the turbos at ATP Turbo, it shows setups with the VW/Audi 1.8T engine using Garrett GT28 & GT30 turbos - makes me wonder which GT series turbo would best match our 951's

Anyway, Chris keep up the good work & good luck!

Thanks for the heads-up Tony.

Vic

 

Chris I am in the same boat as silver bullet. I need a new turbocharger. I am considering all option's...but, alas this is no easy task as there are so many different turbo combination's...and setup's. I want 400rwhp on pump gas with mild boost level's....i.e. 17-18 psi. I would also like the turbo to be capable of running 20+ psi with race gas..for that long straight at Motor Sport's Ranch(tried of getting passed by the big turbo guy's). Any info on the different a/r's and capabilities of these different turbo's would be very benficial...to me and I am willing to bet to other's as well. Thanks for all of your insight...and grat's on your number's. I would really like to not only know about the turbo's but, also would like to know how much they cost..and about installation. I know this is still very new...and you might not even be able to get them.....but, I am very turbo hungry and any help would be great thanks in advance..


sincerely,
john

 

Hey Vic,
Anything from a GT30 to GT35 would work fine for our cars. GT30 would be mild, GT35 wild.
If you wanted a stump puller, the Disco Potatoe would be the one to get - the GT28RS.

I love that name, Disco Potatoe... heh.

Take a look at Garret's catalog. I put the link in one of my previous posts.

Sean

 

Cool Sean,

Thanks

Vic

 

Just an update on this turbo. We went back to the dyno this afternoon after adjusting the wastegate spring and to do a custom chip. Well we ended up with a best of 360 rwhp @ 6200rpm and 350 ft/lbs @ 4900 rpm. This was at 1.3 bar of boost or 19 psi.

I will post the dyno chart later.

 

This is the dyno chart at 19 psi. If we replaced the factory intercooler with an improved unit I think it would make more power.

 

This is where it ended up at 1 bar. 326 rwhp @ 6200 and 308 ft/lbs @ 4900.

 

Chris,
at 1bar, the Dynojet results would be something like 350-360 i believe. nice.

If you're relying on chips to dial in your maps, you're probably leaving some hp on the table... I used the SMT-6 on my car and it works great. A friend and I got the maps dialed in via real time tunning and datalog tuning in about a half day. very nice.
The other thing you might find is that your MAF is may be maxing out.

I can give you the pro-flow part number im using. its set up for 75lb injectors and at least 500hp.
at 15psi boost, Im getting ~4 volts.... so I've got room to spare.

The APE chips work great, only problem is they have a little too much fuel in the idle cells

FYI, all this info will be eventualy posted on my web site as well. On of the first projects I will post is the "DIY kick-*** MAF kit"

Sean

 

Sean I am with you. Since we basically a custome turbo install it may sound strange but my customer is trying to keep costs down so we went with what we had as far as engine management goes.

The next car is a Motec controlled engine so that will give us better numbers for sure.

Thank you for your input.

 

Right on Sean!!!

Can't wait for your "Do it yourself MAF" pointers. Which piggyback will you be using?

I've just got a chance to see an SMT6 working on a running car. I must say that the tuning software lay-out is very nice - light years ahead of the Link AFM MAP stuff.

Can you send me the part # for the Pro-Flow MAF & do you know if this sensor will work with smaller injectors ie. 55lb'ers?

BTW, great numbers Chris. Your turbo looks very promising. At what RPM do you hit full boost? Your A/F sure does look solid - do APE MAF's have fuel adjustability? Keep up the great work man!

Thx guys.

 

Thanks Vic. It reaches full boost at about 3200-3500 rpm. At 1.3 bar this thing is an absolute rocket. Any adjustability is in the chips and changing the fuel and/or timing maps. There is a provision for adjusting the base CO but that's it for the MAF.