Clipping Big16g cons AND pros

[13secGST]

Ok. Basically I'm going to buy a big16g maybe by Friday but definetly before next friday. I've been told by Mike at DSS that I should get a one with a clipped turbine.

I have also searched here and heard a lot of negative stuff because it only reduces the effieceny of the wheel and takes longer to spool while adding ever so slightly on the top end.

While researching I found that people with TDO5 20g's clipped went from 116mph - 121mph in 1/4...really I'm not big on the 1/4, I'll be running pump gas 95% of the time and want a really good street car. Thats why I'm going with the big16g.

What do you guys have to say...is it worth it on a big16? Since I basically want a steet car I feel kind of negative about it cause my mid range is also very important. Also I heard that a clipped big16 can boost 26psi vs. 23psi on an unclipped, is that true? I thought the wastegate opened before that. 3 more psi could mean a lot in the hp arena as long as the turbo is still effiecent. But I also have a VP FMIC kit on its way...soo

Please nobody say...its bad or its good, I am looking for opinions on why it is bad and hopefully people that have driven cars with both could inform us on the pros and cons of each vehicle.

 

[Blk_99gst]

I have a big16g with a 10deg clip in my 99gst. I also wanted the best street able car, and the big16g was as big of turbo as I was ever going to get. I knew clipping it would get me some extra pull on the top end. And once I got the turbo on my car, I knew I never wanted to pull it off again just to send it somewhere to get clipped. So I got mine clipped from the start.

I can only comment for a clipped big16g. I haven't raced an unclipped big16g gst with similar mods; so I don't know if I have more top end then him. Spool up isn't bad at all. If starts coming alive around 3000, and I have full boost before 3500 (I'm pushing 19psi).

If I had to do it again; I'm not sure if I would go clipped or not. Just like you, I've read a lot saying that you shouldn't clip the turbine wheel. But if you or I are looking for more earlier spool up time, I might switch to the gm maf translator which is suppose to knock 700rpm off of spool up time.

As far as your question about 26psi v.s. 23psi. The wastegate will open at whatever psi you have set on the boost controller (and that your bov can handle 20+psi) Both turbos (unclipped and clipped) would be capable of making 23 or 26psi.

Good luck with your decision. Let us know which route you go with.

 

[13secGST]

Originally posted by Blk_99gst

As far as your question about 26psi v.s. 23psi. The wastegate will open at whatever psi you have set on the boost controller (and that your bov can handle 20+psi) Both turbos (unclipped and clipped) would be capable of making 23 or 26psi.

Good luck with your decision. Let us know which route you go with.

Well...I've heard that the internal opens no matter what when you get to a certain psi. clipped around 26 and unclipped 23 and it was because the clipped flows more through the turbine and doesn't put as much pressure on the wastegate at the same psi.
But thank you for your input...I'm also looking at 10deg if any
3500rpms seems pretty good for a 16g especially clipped...what other intake and exhaust mods do you have? ie. UICP? 3" turbo back...

 

[13secGST]

nm I checked your profile...3" turbo back an UICP nice right now I have stock dp, 2.5" test pipe, and 3" cat-back, I also have UICP but when I put on the turbo I'm gonna put on a FMIC at the same time so I'll have full hard piping there. VP kit

 

[JayHass]

Instead of clipping put a bigger housing on the turbine. 8cm or even a 10cm. This way you get more flow and keep the integrity of the wheel.

BUT IMHO if you want a pump gas street turbo, get a small 16G. It's more efficient even though it doesn't flow as much on the cold side it will allow you to run more boost on pump...unless you have a HUGE FMIC then it really doesn't matter.

 

[13secGST]

yeh when I put the turbo on I am putting a VP super street kit on at the same time...the core is 24x10x3 I think. So yeh it is a huge fmic

BTW I just talked to Mike at DSS and he said that you want a big 16g clipped because if you don't it will flow the same as a small 16g cause it has the same turbine wheel and housing. But I think I'm gonna go with Slowboy cause I can get a better deal there.

 

[tsi_turboawd]

did you get the BIG 16G clipped 10* yet? ..how do you like it. Im thinking about getting a clipped B16G also.

 

[13secGST]

yep...I got my turbo clipped, its not bad spool up. With everything I have done to the car now its actually pretty good...like by 3600 and first starts to spool at 2700. Thats what my DSMLink recorded when doing a 3rd gear pull...

But once I adjust my low end timing more I think I can gain a few hundred rpms.

I would really think hard though about your turbo upgrade, because the turbo you choose will be the limit of your power. And if you are going big16g, then I would look into the EVO III 16g because it has a lighter weight wheel that will most likely reduce spool up. and a lighter weight turbine housing.

Now would I go clipped again? Hmmm I'm having a hard time deciding. Cause it depends...I actually probably would, because right now my turbo spools quick enough to spin the tires in second...if I wasn't clipped they may spin even worse...but No, I don't think I would go clipped again...I would get a LSD, like I am going to now...to control the wheel spin.

 

[m1k3]

If you are worried about the wastegate opening too soon you can either get a stronger actuator or go external.

 

[mike9146]

I haven't owned a non-clipped B16G, so I really can't compare, but on my 1G with stock compression/FMIC/3" exh. I see 15psi on my SAFC at 3050 RPM in 5th gear. Your higher compression should lower that figure if you have a free-flowing exhaust and intake path.

 

[13secGST]

if your going in 5th gear then...yes you will see a much higher boost at a much lower RPM...If you want to go by when I see full boost in 5th gear...well I could tell you that I spike ocassionally to 25psi by 3500

Ohh and to people who respond to earlier posts in this thread...look at the date...this was 5 months ago...I understand about wastegates and other things now...but thanx for trying to help

 

[theTuner]

it might just be in my head... but i have a b16g clipped and ported ... and like i said it just might be my imagination , but my 3rd gear top end is pretty quick, for such a small turbo, i love it