got ya! :wink:

Quote from: Josh R.Yeah, if you look at a compressor map for the T-2small T-25 that they put on the TGP you will see that the efficiency takes a dive over 12 psi.  There's no point to run more boost if the air is superheated to such an extent that you'll probably make less power if the detonation doesn't kill the motor.  Here's an example, my friend has a stick '88 Ford turbocoupe with a 3" exhaust and a mildly ported head, ranger roller cam w/roller followers.  The stick turbocoupes have an IHI while the auto have a bigger T-3.  He was runing 18-19 psi on the tiny turbo with race gas(109).  His best on that setup was somewhere in the 15.00 range, and he had a bunch of 15.0's.  I talked to him about his car and he turned down the boost to 16 psi, but he still ran race gas and on his first run on that setup he ran a 14.7.  Point in case....more boost is not necessarily a good thing :D

Can I get an Amen?

:D

Jason

so is it cost affective to keep the t-25 and get it upgraded or just get a larger turbo and what turbo is recommened?  My heads are getting done hopefully before track season starts.

i'm not really sure but good question.  i plan on having one stock crossover so i can use the stock T-25, along with another crossover so i can swap to a T3.  Jason, what needs to be done to get that Turbo Coupe T3 to work in your car?  i'm assuming T3 flange, custom oil/coolant lines, custom support brackets, re-clock the turbo, etc.?  would there be any issues with the PROM?  what would happen if you went above 15psi when using a 2-bar MAP?
joshua

The biggest problem with a different turbo is the downpipe.  Basically, this is what you need to do for a larger turbo:

-Weld T3 input flange on crossover

-Modify coolant/oil lines (not too bad once you look at them)

-Modify/replace the downpipe.  You could cut the flange off of your downpipe and weld on a flange for the T3, but the T3 Turbo Coupe downpipe housing has the wastegate built in!  I'm working on a solution for the downpipe issue now, and I'll let everyone know what happens...because there will need to be other custom stuff.  I'll take lots of pictures.

-Hookup the compressor side piping (easiest part)

As for running more than 15psi with the chip, don't worry.  The larger turbo can flow better / more at lower a psi.  Example, for the T3 to make the boost the T25 does at 12 psi, it would only have to spin like 4-6 psi (it's a guess).  

I was looking on a turbo website, and according to my engine/turbo specs, I only need 8-9 psi to make 280 HP (at the crank).  Of course, in practice everying is not perfect, so I'll probably be at 250HP.  That doesn't include the headwork that is going to be done to the heads, so who knows.

Jason

Dude, its so great to have some guys like you here helping out!  Back from 1995 till about 2000 I was extremely active on the 2 TGP Message Boards at that time, helping out tons of people in every topic and like you, if you have learned a lot/or the good info, you can offer a lot of help to those coming up the ranks.  I know not that many know me here as I have been to busy the last few years with all the projects to help TGP owners out that culminated from those 2 previous boards and 5+ years of posting (just like is starting to accumulate here), but that is nothing AT ALL as compared to the many more emails to me direct, to the tune of over 2,000 TGP owners last I checked!!  So anyways, glad to see others like you giving out good helpful info such as your clear posting on boost not the factor for power indicator.  Like you say it?s the mass and density of that air that makes a turbo fill an engine with quality power-making air!  If I can add, the T-25 we have is rated at 29 lbs/min of air flow, good for about 260 hp, hotter days and the intercooler is very much needed and excellent marks for McLaren to spec us with one (made then by BlackStone, that I think was bought out by Spearco as our intercooler is listed there now).  The stock turbo has a 70 compressor wheel trim and a 62 Turbine wheel trim along with the compressor A/R of .80 and Turbine A/R of .68.  The biggest upgrade to the stock TGP T-25 housings and internals, so that is can bolt right back on is 36 lbs/min, enough to support 300+ hp.  If someone wants more then as you say, custom work, for only a few owners, that I would like someone else to tackle as its too time consuming for me when I have so many more regular TGP owners I am trying/will be able to serve.  

More and more since 1990 when I first got into the TGP (after I amassed a huge library of info on the TGP) I found increasingly larger amounts of emails from those 2,000 plus TGP owners (and many with a TGP motor in an X?) to the point I had to go off line/stealth mode so I had any personally life left (I don?t, my TGP has been sitting for 4 years now waiting for me to tune it, and my Typhoon is dead and untouched now for over 2 years now!).  So this should explain why most people here don?t know me from another lister.  I don?t really want to say this from fear of being bombarded again with emails but (I PLAN to get all this info into my web site IF I get time away from emails and projects!!), I do know Wiley McCoy (and others I will not say) and a few others partner in this excellent automobile.  I also have all the info on the Pikes Peak racer, 1989 Dayton Pace Car, and so much more history, pics and info that it gets me too excited to think about it.  And being a mechanic/tuner and all that, and with taking extensive care of a few dozen TGPs here, and working with many of those 2,000+ owners on troubleshooting, I have gained a great background on all the workings with the TGP (though I am humbled by others like Shawn Lin for getting things like the electronics/gauge cluster/remote door control etc well figured out with excellent details/pics on how to fix these!!).  I will have pillar pods (partnered with Chris A on this one), and other needed plastics made up such as the vacuum block clip on top of the throttle body, and many other items those 2,000 emails and the postings on Message Boards and Talk Forums has shown me.  I have been tuning TGPs since 1990 when I got my first, ran a home-made fuel cut defender, for sure ran a Diacom Data-Logger, installed a boost control over-ride, gutted out my AC fins in front of the intercooler, upgraded to a better air filter, and lots of other fun that great turbo tuners guys helped me in understanding.  Some of those guys I miss as they were truly awesome, one guy who was the best was Lance Ward, who went off to Accel to work with the Meany borthers who designed the first DFI, Lance was a tuner/programmer and too smart for most people, now Lance runs with others, his own Engine Management company selling the great FAST system (Fuel-Air-Spark-Technologies).  Lance?s own Grand National has been running 9s for years, and he did all the work to it, even was one of the first guys to mod the ECM and tune the stock chip to run with no problem, huge Peak and Hold injectors, and so much more.  Frickin nuff about me, a few listers here thought I should fess-up on who I was so people would understand me better, my intentions, my commitment, my background etc but I cringe on how my email box is going to fill up :shock:

Jeff M

OMG, he is alive!

Welcome back Jeff!  Great info as always.   When can I come up there to show you my TGP STE and talk about stuff?  I want to see what you are working on now!

I've been wondering about the prototype TGP.  I've read it had like 305 HP/220 Ft lbs.  I'm assuming the engine is somewhat similar to the production setup, but what about the turbo/chip?  What did they do to make 305 HP?  

Hope you don't become a ghost again!

Jason

Howdy back, glad you liked the info, on the other Forum some people there complain about my posts being too long (they can be quite long).  But from me being quite active on the internet since 1995, I have learned over the years that it?s better to give all the info up front so people can have all they need (that I can give them) to learn/debate/discuss from, and save posts back and forth asking the next obvious question, but instead then the final questions that we all seek.  Second is something unselfish, and that is aside from the few guys participating in the post at that time is those who will come there over the next (?) years looking for the same info, less we want to hear again on ?how do I put the TGP turbo in my X?)  :) .  So I have to polity ignore those statements on my hogging page space less the Forum owner asks me, but from what I have found (not to brag!) is that when I and others write a good chunk of useful info, it gets asked by someone with a web site if they car use it for their FAQ, that is something that makes better use of peoples researching time I believe, but it still is fun to yak, debate, learn some more, help each other on equal terms, no matter their level of experience!!!

As for the proto-type, it ran a larger custom made intercooler, larger T-3 turbo and a nice big air filter that we should have gotten!!!!  That larger/more mass air turbo and the nice big intercooler helped immensely on the power end, but as you note and an odd thing, the hp quote was 305 but the torque was only 220 lb ft!!!  That tells me the turbo was set to spool slowly and peak higher/more mass air later than ours, and with the problem of traction when I have pushed around 280 hp, can understand why they went that way, I got some ideas for that problem!!

Being a ghost for me has been a necessity to not only stay sane, but get lots done to help the TGP community with what it needs/wants. You will get a taste when you visit, though we will have to make it short and intense for me as I got too much always waiting for me to do.  So, email me private and we can talk a good time for both of use to hook-up, and for you to check out all the behind the scene activities going on here, might want to bring a digital camera (I don?t have one yet) as you will be mad if you don?t  :shock: .

Jeff M

Jeff M. posting long posts? That's an understatement... :lol:  J/K Jeff. Good to hear from you.

Do you controll the tq from the turbo chip to keep the trans from going into peices. I think this is only a problem in a takeoff and not when you are already in motion(seen those FWD dragsters snap drivetrain parts only on takeoffs and not after words too often).  Then again you do control tracktion with your chip in the hole-I guess the same thing as keeping the trans from going boom w/slicks.

I know GM has controlled the power from the SC3800 to keep the 4l65-e from going "snap". After maket chips ignore that procaution and make thouse engines have alot of grount down under and then goes bye bye trans.


AAA . Any Ideas for an aluminum pan on those TGPs with a sheet to controll the oil from dancening in air when autocrossing or just having fun at a empty field. I am sure those 440s would benefit from one.

Ahh it ain?t so bad.  Of the few TGP owners that have had problems with their tranny, most of that was because of the tranny shop not knowing this tranny and what to do for it, kind of the same issue I hear from the many TGP owners I have talked to that have asked for my help because their service garage or dealer has either messed up their car or could not figure out the problem with their engine or whatever.  I can?t fault the service garages or the dealers so much, there are not enough of these vehicles out there to give a shop enough experience to working easily on one of these.  As for the rest of the owners/trannys, I know guys with 180K and more miles on original tranny, engine and turbo, some guys with over 260K miles (original components unknown but still on the road).  I also have one TGP owner who has run over 150 drag races at the track clocking some mid 13?s corrected and has lasted just fine, even though he lives in scorching hot Arizona, amazing.  I have some chip?d guys that have run for several years with no problems, though I can setup the chip to maintain the torque management features, GM has these so if someone is really nasty to their tranny, they will not see any warranty claims, specially if the owner opted for one of the many extended warranty plans, out to 72months/100K miles.  Indeed some owners have not liked it when their tranny died, main cause, and more people are believing this now and less confirming it (pun intended!!!) is high speed runs at 90mph plus!!  The thing is what I have said many times before, 4th gear only has one clutch and one steel, not a lot to hold the power transfer to push a car through that much air at 90+ mph (even if there are some other gears joined in, 4th still plays the main part).  I proofed this once myself, under warranty, when I exceeded 150 mph, then after getting cocky another day, was running 100 to 120 mph up a deserted highway for an hour or so, after that my tranny was shifting into 4th gear at WOT, that is not supposed to happen (to save there being that much power at WOT on poor 4th gear) and I knew I got carried away, and paid the price when I finished my 6 hours trip only to come to a stop and never move again, at least until the tranny was replaced (under warranty, that is supposed to be the time you beat on your car).  Another less common problems is the fluid running away from the pickup and the tranny pump running dry, not good, a local guy here took out his TGP tranny after a few dry runs like this, but the fix is as stated adamantly by Mr. Shift Gil Younger (the guy who owns, runs and does all the stuff) of TransGo, to overfill the 440-T4/4T60 by 4 quarts!! I do not want to take a huge amount of time debating this claim, both my TGPs and all the local TGPs here have been running this 4 quart over for years, and many in other states that have headed the warning, benefit of adding more fluid.  This extra fluid makes sure there is enough for those who like to zoom around highway merges like the fat tired TGP can do, and any autocrosses you might tackle.  

As for any other weaknesses in the drivetrain, tested that one too, speedo read 120 mph going around a corner at about 15 mph, then the tire hit a pot hole, shafts held, front end did not bend, nothing happened except the tranny case cracked!!  Good testament that the drivetrain is able to take more than anyone could throw at it, and a long way even from some good hooking slicks.  And there has never yet been a dead 1st gear, I mean if you give that a thought, 1st gear in applied soon as you put the car into driver, no changing from one gear to the next like 2nd, 3rd and 4th, and there is some good design clutches in 1st.  I do hear you on the FWD drag cars, their shafts were not designed for any big hp, but ours is a pretty fat guy.

So, indeed there have been some dead trannys, but I look at it with this analogy; on eBay there are guys who have sold over 40,000 items, and have 39,990 positives, and 10 negatives, you can?t always be lucky, perfect, please everyone all of the time, or never see a repair bill.  So frequency of failed 4T60 is not such an issue for most, fact is the 4T60 was renamed and completely redone internally to leave behind the very poor history of the older version 440T4, it was a crap pile to own for many.  

Hope that was informative and entertaining as well :) !

Jeff M