best throttle response ideas for 2.5L

[cs daytona]

other than buying a stock t1 engine and/or car. im brewing up some ideas for a big power 2.5L with instant throttle response for autox and road race application but still practical for daily driver. can yall please reply with a setup that works great for you and why?

this is what ive day dreamed up so far:

lightweight steel flywheel
lightweight pulleys
stock 1pc intake, just cleaned up smooth runners (for velocity)
stock throttle size ?? (also for velocity)
water/air intercooler where the battery would sit (shorter pipes)
garrett disco potato ?? (or too small?)

still on the fence:

use swirl head or g-head (milled for same compression)?
higher (8.5:1) compression/low boost or leave it alone?
big valves or just back cut valves?
1pc or 2pc intake? ported?
larger throttlebody?
header or ported manfold?
if header, log or tube?
stock cam or a little bigger?

thanks guys for the input. trying to see what i can do with what i got already, without going 16v.

travis

[mario03SRT]

Lightened Crank
Alum Flywheel
Big Wheel Mitsu Turbo
Alum Rods
Lightweight Wheels
Ported Head
2.5" Exhaust no Cat
8.5 to 1 Pistons

Just off the top of my head.

[GLHNSLHT2]

hehe you'd like my car, has wicked throttle response.
2.5
Ported head by Tyler Van Lant with Manley valves that are between +1's and IMSA, Comp 26995 Beehives with appropriate hardware
JRB Tube header
BR Intake plenum on top of heavily ported lower 2 piece and bored out 58mm TB
S60 turbo with ported exhaust housing, wastegate hole and ported 3" TU swingvalve connecting to 3" straight pipe side exit.
Had a cummins i/c, when the engine goes into the new body it will have a big a$$ 3" in/out treadstone i/c in the nose.

The S60 spools up faster than a VNT. I have boost coming on at 1300 and full boost before 1700rpms. It feels like a big V8 car. Instant torque. I have a pretty sweet suspension setup that pretty much negates the need for a posi and if I even think about touch the the boost in 1st and 2nd gear around a corner both tires go up in smoke and I'll go dead straight. If the corner is bumpy you have to make sure your foot is locked because if it bounces off the pedal the car is gonna jerk itself all over.

I'm gonna try a 52mm TB after it get's re-installed to try and take away some of the throttle response. It'd be sweet on the track but on the street it can be a bit difficult.

[cs daytona]

glhnslht2- yea dude, sounds wicked! would be great with some slicks! u have a swirl head i assume? how do you think the g-head would act, assuming the same port/valves/chamber cc, etc? i was reading the of the slow pressure rise of the g-head design that might make it harder to detonate. you think the overall design of the swirl head would be a better choice anyways as far as response throttle goes?

also, your setup is basically big airflow, smaller turbo? why did you go s60? do you have pics of your intake plenum? sheetmetal im assuming?

mario- what is this big wheel mitsu you talk about? will it be too small for my 2.5?

thanks for the responses, keepem coming!

travis

[GLHNSLHT2]

Yes swirl head. The Ghead definately needs more spark. I think the swirl give a better burn. Not sure how either react in terms of throttle response.

Yes my setup is for big airflow. I went with the S60 because it was on the car with the more stock stuff. Couldn't afford to plunk down the cash for the big turbo I want at the time. IMO I wouldn't go anything smaller than an S60 on any 2.5. It's a great street turbo that would start making boost at 2100rpms and be spooled by 2500 when my engine was stock with a ported exhaust manny and 3" exhaust.

Anyway the next turbo is going to be either a 50 or super50 trim T04E compressor with a new "F1-57" (new style stage 3) T3 turbonetics. I'm hoping to decrease the spool time to be more like a stock T2 coming on about 2500 and be full song no later than 3200rpms. Should soften the power curve just enough to make it more driveable and really give it a nice top end rush.

Pics of my top end here: http://www.pnw-sdac.org/gallery/main.php?g2_itemId=3074 and of all my other junk here: http://www.pnw-sdac.org/gallery/main.php?g2_itemId=1713

[cs daytona]

wow amazing work dude! im guessing that header isnt being made anymore? looks sick! how much you making those plenums for? (for later reference and gotta find a 2pc first) im about to send you a PM. maybe you might be interested in something.

travis

[GLHNSLHT2]

No that header is a one off piece that was made oh probably 9 years ago. It was a test to see if it was viable to bring it to market but the maker said he'd have to charge like $900 to make any profit. I happened to be watching the web at the right time to snag it up. I finally got to use it oh I guess it's been just over a year now since I put it on.

[mario03SRT]

glhnslht2- yea dude, sounds wicked! would be great with some slicks! u have a swirl head i assume? how do you think the g-head would act, assuming the same port/valves/chamber cc, etc? i was reading the of the slow pressure rise of the g-head design that might make it harder to detonate. you think the overall design of the swirl head would be a better choice anyways as far as response throttle goes?

also, your setup is basically big airflow, smaller turbo? why did you go s60? do you have pics of your intake plenum? sheetmetal im assuming?

mario- what is this big wheel mitsu you talk about? will it be too small for my 2.5?

thanks for the responses, keepem coming!

travis

They take the stock Mitsu Turbo and install a bigger compressor wheel and clip the turbine. Some reduction in spool but a good jump in flow w/o any real spool compromise. The Mitsu turbo already has ZERO lag so it will still be snappy but with more punch. And it will be a direct fit w/o and thing needed but more fuel. Just bump your base fuel pressure a tad and let the adaptives do the rest. Similar to the Enforcer 1 for SRT's.

FYI,
Marion

Marion

[cs daytona]

cool! good to know, ill have to ask cindy about than one. mitsus seem to be plenty abundant in the pick a parts down here.

travis

They take the stock Mitsu Turbo and install a bigger compressor wheel and clip the turbine. Some reduction in spool but a good jump in flow w/o any real spool compromise. The Mitsu turbo already has ZERO lag so it will still be snappy but with more punch. And it will be a direct fit w/o and thing needed but more fuel. Just bump your base fuel pressure a tad and let the adaptives do the rest. Similar to the Enforcer 1 for SRT's.

[TheCanadian007]

Curious question, somewhat off topic, I'm going to be running a Garret T03 turbo off a Spirit R/T (.48" A/R). I'm swapping the exhaust housing with one from a T2 Garret, so I won't have to drill and tap the manifold for the T3 pattern. On an unported, mostly stock 8v engine with a 1 piece intake, 2.5" exhaust going through a glasspack, at which RPM would one expect it to fully boost to 12 or 14 psi?

With a 52mm throttle body, would one have excessive turbo lag and poor throttle response for a city daily driving vehicle?

Cheers, TheCanadian

[R/T]

Put a turbo "bypass" valve before the TB.

Like a reed valve intake on a 2 stroke engine.

The engine would suck air through a one way valve before boost builds up, and react like an NA car.

When boost builds, the valve shuts and you'r turbo'ed.

Been wanting to try this for a while....

[cs daytona]

Canadian- is ur engine a 2.2 or 2.5? Im guessing the r/t turbo wouldnt be that much bigger than a t2 garrett.

R/T- are you talking about an intercooler bypass? Like a pipe between the discharge pipe and just before the tb? Ive been thinking the same thing but never thought of a reed cage setup. Thats a great idea! Thanks

travis

[WLKivett]

... it was called a D valve on here years ago.

[Reaper1]

If money is no object:
-lightened crank
-light custom steel or titanium rods
-forged pistons 8.2-8.5:1
-nicely ported swirl head with conical springs, PT lifters, titanium retainers and keepers, nice roller cam (roller S60, or F3/4)
-custom ITB intake with sealed manifold(like Warren Stramer's)
-equal length tube header with a smaller GT DBB turbo, or larger Mitsu(something like an 18G possibly)
-3" exhaust from turbo back, no cat, muffler optional
-IC is your choice, but I'd stick with air/air if it were me(lighter, simpler, works fine for your design goals)
-lightened stock flywheel (see TU's options)
-lighter pulley set (I'd personally almost like to see a light version in a slightly less underdriven configuration than what is currenly offered inlcuding PS pulley, water pump and alternator pulley)
-modded/ported water pump (or an electric one)
-blueprinted oil pump and modded pick-up
-windage tray/crank scraper
-adjustable cam gear, custom light intermediate shaft gear
-clearly a custom tune set-up
-lightweight wheels

I think I got most of it! LOL That should be able to get you a good 3-400hp at the wheels, a rev capability safetly to 7500rpm(or more possibly), and VERY snappy transient response! Nah...I've never thought about this...

[Reaper1]

Put a turbo "bypass" valve before the TB.

Like a reed valve intake on a 2 stroke engine.

The engine would suck air through a one way valve before boost builds up, and react like an NA car.

When boost builds, the valve shuts and you'r turbo'ed.

Been wanting to try this for a while....

... it was called a D valve on here years ago.

There is a product being marketed now that incorperates this idea WITH a BOV. It's called a "sonicvalve" or some crap like that. Yes, it was called a D-valve a long time ago because Gary Donovan "came up with it"(I'm sure the idea has been around much longer) and made one out of regular stuff from Home Depot. Does it work? Sure. Is it needed? Not if the whole engine is put together as a system and is tuned correctly!

[TheCanadian007]

Canadian- is ur engine a 2.2 or 2.5? Im guessing the r/t turbo wouldnt be that much bigger than a t2 garrett.

The engine is an '88 2.2 T1 out of a Lebaron. It's mated with a turbo spec A413 tranny and is going into my light L-body. The turbo has a .48 compressor housing, with a 45mm inducer - It's a tiny bit larger than a T2 turbo. Non ported intake, non ported exhaust.

[TurboRon25]

Yes, it was called a D-valve a long time ago because Gary Donovan "came up with it"(I'm sure the idea has been around much longer) and made one out of regular stuff from Home Depot. Does it work? Sure. Is it needed? Not if the whole engine is put together as a system and is tuned correctly!

I believe it was called a "D-valve" because it was first implemented in all it's Home Depot glory by the FMMLs resident rocket scientist, Dan Culkin.
Please correct me if I'm wrong, Man that was a long time ago.

Ron

[Reaper1]

I believe it was called a "D-valve" because it was first implemented in all it's Home Depot glory by the FMMLs resident rocket scientist, Dan Culkin.
Please correct me if I'm wrong, Man that was a long time ago.

Ron

WOW!! Yeah, that was what seems like infinity ago! LOL Maybe it was Dan. I remember that Gary tried it for sure though on his Daytona.

[cs daytona]

canadian- you would probably really like the t3/t2 turbo your talking about. i liked by original t2 alot until it took a poo on me. the hybrid turbonetics i have now is good for a more built up engine. around town, i still miss my t2 garrett!

reaper- ill never know how it feels to have the "money is no object" feeling LOL! but i know pretty soon my engines gonna be out again for something stupid anyways. so i just thought id get some ideas on how to make a DD/weekend warrior. on a side-note, what size ITB throttlebody would be good for what i want? off a motorcycle maybe?

travis

[Reaper1]

Honestly I hadn't gotten around to doing the calculations to figure out what size ITB's would be good, but Warren Stramer could praobably point you in the right direction!