What size of wastegate is necissary ?

[inatalonIXLR8]

I've got a 2.4L stroker w/ 1st gen head, and I'm looking at buying a Garrett GT30R turbo. The engine is built for major power, but to break it in I won't run more than what the stock drivetrain can handel. Less than 400 Hp?

The exhaust manifold I bought has the 2 bolt flange for the 38mm wastegate, but I believe there's adapters you can buy to put a 50mm wastegate on is there not?

I would hate to have to buy parts over again if there are no complications with running a larger than necissary gate. Can anyone tell me what size gate is manditory for each power goal?

Also, I'm not sure which GT30R turbo to get any ideas?

Thanks as usual for everyones help!

[E-Klips]

I run a 38mm WG with a GT42r which is a hell of a lot larger than a GT30. Its not about how much power you make, its about how the turbo performs. I've never had problems with the 38mm WG. If the turbo spikes boost a lot, you might look into a larger WG. By the way... A 50mm WG is way overboard for your turbo. A 38mm WG would be fine, especially if its mounted on the manifold.

[crunchymilk55]

38 is fine

[inatalonIXLR8]

At what Hp levels should you up grade to a larger wastegate?

And any ideas on what trim GT30R I should get?

P.S. Thanks Crunchy, you always seem to cruise the new questions and give informed opinions, I for one have always valued your input.

[E-Klips]

Just so you know a 2.4L isnt a stroker. You might want to look at something a little larger than a GT30r just because it might be a little small for that motor. A GT35r would be perfect. Or if you want to stay bolt on, FP3065 or FP3575. But it all depends on what your goals are. Those turbos will all spool pretty quick on a 2.4L motor.

The stock drivetrain can handle a lot more than 400hp. Just get a good clutch and you'll be fine.

To tell you the truth, I wouldnt worry about a large wastegate until you are running very high boost. If I decide to run methanol next year I will probably upgrade to a 44mm wastegate just due to the fact that I'll probably end up running 50psi of boost. Right now I average 42-45psi just due to the turbo spiking boost because the wastegate cant open fast enough.

Like stated before, a 38mm wastegate is fine, especially if you already have a manifold flanged for one. You could get the adapter 38mm to 44mm but I dont think its really worth it.

Do you have a 38mm wastegate already?

[inatalonIXLR8]

No not yet. I've been cruising ebay for a Tial model, but it's getting hard to tell which are real and which are knock offs!

[E-Klips]

A tial is a very good choice. Like I said, since you already have a manifold flanged for it, might as well go with it. Plus it is cheaper than a larger one.

Now, about the turbo... What are your goals?

[crunchymilk55]

Just going to throw some info out there regarding turbo choice.

On a 2.3 or 2.4, I wouldn't use anything smaller than a GT35R (which is a great turbo btw). Now obviously if you are looking for very fast response times and really quick spool up then you'll be fine with the GT30. However, most people that choose a 2.3 or 2.4 are usually looking for major power and really quick times. To do that you will need a larger turbo. Like E-klips mentioned the FP turbos are a great choice. They also have turbos with GT40 wheels stuck in GT30 housings.

Regarding engine break in, not sure how much you've read about it, but I wouldn't use a new turbo (whichever you end up getting) on engine break in. There are tons of threads debating this on different forums with people having perfectly fine turbos after breaking in an engine, but there are also those with trashed turbos as well. A local here ruined a new 50 trim even though he changed his oil quite religiously with the break in and did all the steps correctly. 100 bucks for a 14b now is a lot better than a rebuild.

[inatalonIXLR8]

So the GT35R hey? I've been hearing that from a few other people as well. I would like this car to be a daily driver geared towards autocross more than drag racing.

You guys are right, I would hate to send a verage of fine metal particles through a brand new turbo. I've already got a nicely working 14B that I probably should use. What will the boost cut be like with that set up?

Which of the Gt35R turbos should I get for after the motor is broken in, and do you know of a good place to pick one up for a more than resonable price?

And lastly and most importantly, engine management. There's a local dealer pushing a high priced Autronic set up that looks good, but I've been leaning more to AEM. Or do you think good old DSMlink is up for the challenge?

[Black99GST]

i would go with DSMlink... It pretty much kicks A$$ bang for the buck wise...

[inatalonIXLR8]

Do you run the GM maf with that, and would it be capable of running the 2.4?

[Thor06]

You can run a GM MAF if you like and yes, it'll work on a 4g64. I would get whatever GT35r you can, I think they are all about the same, but I dont really know. On garrett's website they are all rated the same except one IIRC so they cant be too different.

[crunchymilk55]

well if you really want to keep it autoX than the 35r might be a bit much. It's not laggy on a 2.4, but for autox you pretty much need instant boost. Then again turbos cars are never really that good at autoX regardless of turbo size. A smooth powerband > turbo's powerband when it comes to autoX. I even find the evo3 a bit laggy when I'm autoX'ing.

and yes, DSMLink.

[kjewer1]

For autox I would agree with the GT30R, probably for the first time ever Definitely a minimum of 35R for drag race though. I would go with a larger 30R, like the 3076 for example (55 lbs/min). Good for about 500-550 WHP, and should make full boost on a 2.4 at about 25 psi.

The WG thing is really a non issue IMO. It has nothing to do with the size of the turbo, or the amount of power you plan to make. It's all about how much of the turbo's flow you are NOT going to use. After all, isn't the function of the WG to dump excess exhaust flow? A 30r or a 35r on a 2.4 will not have a lot of exhaust flow that needs to get dumped, so a 38mm will certainly suffice, unless you plan to run ridiculously low boost for some reason. I ran a 38mm with 20 psi spring on my T67 on a 2.4, and it would hold that 20 psi to redline with no creep (venting all 4 runners).

You only need large WGs running large turbos at very low boost, since you will have a lot of exhaust gas to bypass to be able to run that low boost. Larger gates also have the downside of being easier to blow open, same as internal gates (force = pressure * area). If you are putting the gate on the O2 housing I do recomend going a little bigger, since it is harder for the exhaust gasses to get out. In fact, FP did step up to the 40 or 44mm gate on thier bolt on turbos with thier cast stainless turbine housings.