GTI-R engine question

[Caplax40]

Hey guys,

I'm thinking of going the turbo route with my Classic SE-R. It has a DE in it that was just installed, but things have changed and I'm pretty convinced that I want boost!

I was looking at the Turbo & SR20 FAQ and had some questions:

What is the advantage of the GTI-R's quad throttle bodies?

A local shop has an Avenir motor and FMIC in stock, but would it be better to go the GTI-R route? I assume that's the king daddy of the FWD sr20det's?

And I assume that both (or all DET's?) motors will bolt right up to the DE's transmission? Will it be strong enough to hand the power?

Thanks fellas.

[nametakennow]

I'll go backwards...

Yes, the trannies bolt up, and yes they are strong enough probably on up to about 300hp. After that things might get interesting. A B15 transmission can take a bit more load than a B13/14, in case you consider swapping that too.

The Avenir motor is a good bet. It's got a ball-bearing T25 at 9psi stock. However, the GTi-R motor is definitely the most powerful. Unfortunately, the swap is a bit more involved. I don't remember the details off-hand, but I could dig them up later.

ITBs are fun stuff. They net more power, but they're also more stuff to worry about breaking. The same goes for the GTi-Rs strange mechanical valvetrain. Replacement parts for GTi-R motors are tough to come by.

Here are the biggest questions: What will you be using this car for? and Do you have a pretty good amount of disposable cash around?

[RED_DET]

Leave the GTiR motor for someone with good tuning capabilities and experience with the motor. Get the Avenir and call it a day. Stock boost with right size exhaust is going to net you around 215whp. The turbo is ball bearing as already mentioned, which is going to spool crazy fast, considering a journal bearing turbo already has crazy spool, full boost before 3000rpms. The GTiR is built a little more "stout" than the other DETs, but they all can handle 400hp with ease without any internal modifications.

Then as name said, what are your plans for the car? Daily driver, weekend warrior? The avenir with boost cranked up to around 14psi, with at least 2.5" downpipe and 3"catLESS back exhaust will net around 230-240whp. If you want a little more, just get the GTiR turbo and some 444cc side feed injectors with z32 or bored GTiR maf and crank out around 280-290whp. Need more than that, add some cams, then you will be around 305whp. But those few running the GTiR turbo have learned about the internal waste gate being the factor of some detonation problems past 15-16psi. A fellow sr'er decided to run an external waste gate dumping to atomosphere along with s4's. To make a long story shorter, prior external wastegate and cams 301 @ 16psi, 311 @ 18psi with serious detonation problems. AFter external wastegate, 311 @ 16psi, 318 @ 18psi, NO detonation problems. So, an external waste gate ALONE will net you around 10-15whp at each rpm throughout the band.

Now ask yourself do you want 300whp? If so, I know the way and your car will run 116mph in the 1/4, period. I run 111mph with 275whp.

[Caplax40]

Thank you for the reply!

I didn't realize the GTI-R swap was so involving, but after some searching I'd say that it's out as an option.

I think my choices have come down to an Avenir motor or an sr20ve motor. I'm trying to craft a well rounded car that's mostly daily driven (but not always) and that can handle the occasional AutoX. Drag racing really isn't my thing. Because of this, the VE appeals since it isn't turbo charged, there's less stuff to go wrong and it's cheaper. But it's also down on power. With the DET the 220hp mark is just the beginning.

Two items I'm looking at purchasing are the JGY Customs 11 inch brake kit and a suspension that consists of KYB AGX shocks and Ground Control coilover springs, along with front and rear sway bars. These items alone will cut into my budget pretty heavily so that's why the VE also appeals.

Happy Easter btw!

[RED_DET]

VE motors still cost 1500-1700. You can get a DET for that amount as well.

[nametakennow]

If your goal is autox, your suspension is the bigger deal, but it sounds like you've researched that issue and have a decent handle on it.

Either a VE or DET will give you a good autox setup, you'll just have to drive each a little differently.

I don't see a whole lot of VE swaps. I'd personally love to do one, but it has one issue - aftermarket support in the US. With so few VEs around (though they are becoming more common), none of the big SR players in the US have courted it. JWT has been "working on" a cam setup for years now.

Personally, considering this has more DD elements to it, I'd lean towards a VE because you'd be less likely to want to do something ridiculous to it. With the DET you'd be chasing 300whp and end up possibly sacrificing engine and/or turbo longevity to get it. With the VE you'd hit I/H/E and rev it into the 7000s regularly and have a lot of fun, without the worry of blowing a turbo.

Of course, my comments come from the perspective of a frustrated former DE+T guy, but I know that a DET will be a lot easier of a time than a +T. And even pulling my bias out, I still think I'd lean VE.

[Caplax40]

VE motors still cost 1500-1700. You can get a DET for that amount as well.

That's true, but then I have to figure in the extras to get it running. The local shop that has the Avenir has it priced at $1600 bucks. Which is a good price no matter how you look at it. But then I need to get an intercooler plus piping (the shop has the Avenir's FMIC, but I don't know if that's included in the 1600), then I need to get a boost controller, a gauge or two, I assume a clutch that's rated for a higher output (this true?) and then get a 3" inch exhaust system done up. So it really starts to pile on.

With the VE it's the engine at roughly $2000 with shipping, an ECU, the Greddy MSS, some miscellaneous parts and such and exhaust and header.

In the end I'm sure the VE will be the cheapest, but I'm going to be stuck at the 190hp mark, down a minimum of 30hp for the DET. Which is over 10% less.

Ugh, the decisions.

[nametakennow]

The shop that's getting engines usually quotes prices for the entire engine- including IC, piping, and ecu.

In autoX, you won't be using all that horsepower most of the time anyway, and you may actually get better times with the lessened torque steer of the VE.

[Caplax40]

Do you think the weight difference between a VE and DET engine setup would offset any initial horsepower difference?

[RED_DET]

Heres a break down:

DET+ECU: $2100VE+ECU: $2000

Intercooler & Piping: $400Fujitsu Header for VE: $600

New clutch setup for DET: $320-350

3" Exhaust for DET: $200-300, maybe cheaper, it doesn't necessarily need to be mandrel bent, so maybe even cheaper. I had mine done for $50 3 yrs ago.2.5" Down pipe for DET: $2002.25" Exhaust for VE: $200.

Gauges for turbo:BoostOil PressureEGT $200Gauges for VE:Oil PressureWater Temp $100

VE route: $2900DET route: $3250

Simple enough if you ask me. But the bottom line is what kind of power you really want. The VE hype is all fine, but in reality, you could make just as much power as a VE with I/H/E & cams on a DE motor. The most power you are going to see with one hell of a tune is 170-180whp. You put the DET in there on stock boost you are going see 30 more whp. Turn the boost up with a $50 manual boost controller and you are going to see 50-60 more whp than the VE. One no more realiable than the other if taken care of properly. For me its a no brainer, but I'm biased to boost since I have it. Last local VE guy around here put down 165whp, I can build a DE for $1k and do that.

No there isn't going to be that much difference in weight between the two motors to make any difference.

[nametakennow]

This is true. I actually just noticed that a DE with I/H/E and JWT S5s puts out the same power as a VE while browsing around an all-motor SR board.

One thing to mention in those listed parts is that you sure as heck wouldn't want to run a 2.25in exhaust on a VE. Even DEs see gains with a 2.5 instead of a 2.25 when cam'd.

How you managed to get an exhaust for $50 is beyond me. Personally, I'd for a good mandrel-bend 3in turbo-back setup, which will definitely drive up the cost, but also make room for more power up the road.

Still, I see your point, RED, so it's a bit of a matter of personal preference. Though if the power differences are that large, I suppose the DET is pretty much the hands down winner.

[Caplax40]

So, would the usual engine bolt ons (pulleys, cams, cam gears, etc.) along with I/H/E yield as much power as a VE? This might be a good cost/performance path for me. Sure, it's less power than the DET, but it's also less concerns about reliability and breaking something. Not to mention cost.

What are these S5 cams you are speaking of? I looked on JWT site but the highest I see is S4.
Modified by Caplax40 at 8:58 PM 4/19/2006

[RED_DET]

All those bolt ons, plus a tuned ecu will get your close to 170whp. The s5 cams have more topend than the s4 cams. Most report they loose a little power below 3000rpm, but between 5-8000 the car is a whole difference animal. You would probably want to change out the valve springs, retainers and rocker arm stoppers with s5's, especially reving past 8000rpm. If you go with s4 cams, which would be plenty, new valve springs, retainers and stoppers won't be necessary.

JDM SR20:$400Header:$200(SS Auto Chrome header)Cams: S4 cams, $400 used $550 newExhaust: $400ECU: $550 (straight from JWT)Pulleys:$200

Almost 1k less than the VE swap. 160-170whp.

[nametakennow]

And this is one of those rare cases where the SSAC header is actually a very good option. They just made a new generation that terminates into a 2.5in midpipe, which will be a lot better for a cam'd motor than the old 2in setup.

I've heard the same thing about S5s dropping bottom power pretty badly, so for the sake of drivability, you may want to stick to S4s.

Also, installing cams can be hairy, and it's not cheap to get a shop to do it, but still cheaper than a VE swap.

As RED said, valve springs, retainers, and rocker-arm stoppers would be a great investment for a rev happy NA DE setup.

[Caplax40]

JDM SR20:$400Header:$200(SS Auto Chrome header)Cams: S4 cams, $400 used $550 newExhaust: $400ECU: $550 (straight from JWT)Pulleys:$200

Almost 1k less than the VE swap. 160-170whp.

And actually, I already have a JDM engine in there, so that money would go to a shop to install the cams. Are cam gears even necessary?

[RED_DET]

THey could net some more horsepower if dialed in correctly.