Top Mount Turbo Q's

[fabrisuzu]

Let me start off by saying that currently i have a rebuilt (by gpop shop) turbo from a pulsar gtir. I bought the car from a friend of mine and want to start building it to make it mine (built not bought is what i always try and go for). My plan was to drive it daily for a year or two while collecting parts and then make it a fun weekend/track car once i graduate from college.

So recently i came across a real good deal on a peak boost top mount turbo mani, so i bought it. My plan was to wait until i could put say a gt30's series or hx 35 turbo on it, with all the supporting mods naturally. Now that i actually bought it, i kinda of want it on now. I talked to yet another very helpful (being serious) person at Enjuku racing, and he said he would help me source a t3 turbine housing for my turbo if i wanted.

My question to anyone who wants, is would it be worth it to buy the turbine housing, waste gate, and lines then dyno tune or should i just wait till i have the money and go big? I really have no problem spending a little money now (compared to new turbo) if i will see/feel some gains, but dont want to waste my money because i know that some day i will get a larger turbo. Has anyone done this before?

I tried searching the turbo and most info was about trying to get it to work on the s13 sr20det (which is what i have), but because my car already has that, it didnt help me much. If i missed something or there is already a thread on this please let me know.

Because I tend to write novels, basically what im looking for here is are the gains of going top mount with a gt28 series (which is what ive been told i have) worth it or should i just wait? I currently run about 19 psi max and thats where i want to stay for now. Thanks for any help.

[DuckyD]

So you are asking if it would be worth it to convert your t28 to t3 flange so you can go top-mount?

Several thoughts:1) Topmount t28 would spool really quick and that in itself would be fun.2) You could probably sell the t3 flanged t28 down the road and make most of your money back down the road.3) Going TopMount now, you could block off the WG flange on the manifold and run internal gate for now.4) And you would get the coolant and oil lines done and out of the way.5) Depending on which turbine housing you go with, your downpipe should fit about right for whatever larger turbo you get in the future.

In other words, if you have the money now go big-boy stuff. If not, I won'd think you would be doing too much back-tracking later if you mounted and used the t28 now.

My uneducated $.02

[fabrisuzu]

Good things to think about. I really want to go top mount as soon as possible, but i understand that not doing things right the first time means more money and head aches later.

So now that it seems confirmed that it is possible and not working against me, has anyone done this before? Just curious about what results have been seen by others. Thanks for the help!

[fabrisuzu]

Anyone runnin this set up?

[fabrisuzu]

More Dumb Questions:

1) I thought the internal waste gate was some how integral in the turbine housing, so if i went with a t3 turbine housing how could i keep the internal waste gate? Or am i wrong?

2) Ive been looking and i found several t2 flanges that are weld on, would it be working backwards too much to just fab up a t2 mount and literally just move my turbo to the top mount position for now? I found several external waste gate block off plates, and for $16, im not too worried.

thanks

[fabrisuzu]

Anyone?

[Sil80315]

Save yourself a head ache, Just find a cheap t3/t4 turbo go slap on there.

Speaking of Enjuku, Ken hooked me up with the 50trim they sell and I made 372whp at 17psi with that turbo

[fabrisuzu]

thats good to hear, i m looking for those numbers myself. I think if it comes to me having to buy a brand new turbo, ill just save up and get myself a gt3071 or 76r. Thanks for the help, but if it is still possible, i would like to try using mine if anyone has had luck doing this just let me know.

[Sil80315]

yeah but to be honest the gtir turbo wont get you high numbers..maybe 320whp? Im also running cams and ISIS intake manifold

[fabrisuzu]

Exactly what i was looking for. I have read where these turbos (to my understanding they are similar to the gt2871 or gt2540) can make upwards of 380 whp, which is again about what i am looking for. Ill talk to the guys at enjuku and see what turbos they have to meet my needs, but this means that i have to buy an external wastegate which just sets me back a little further. No matter what, i refuse to cheap out, i want to do things right and if that means waiting till i can afford the t3 turbo (even though i want it now lol) i can. I have destroyed my last two vehicles making cheap purchases and refuse to do it on this one. Thanks for all the advice!!!!!

[fabrisuzu]

O and i didnt give enough detail earlier. My sr20det has a freddy intake manifold that has been cleaned up, megan bottom mount manifold, fmic, z32 maf, and a few other goodies including sti injectors. SO your numbers sil80 actually get me excited, because in the near future the top mount and cams are in the works. Thanks again for all the help!!!

[Sil80315]

Yeah im running the ISIS manifold. 555cc injectors, HKS step 2 cams. Turbo fab top mount manifold and the 50 trim 63 ar turbo from enjuku.

Made 372whp at 17psi letting off at 6400rpm.

[fabrisuzu]

Music to my ears, thanks much. I plan on doin the bc head package from enjuku some time after next summer if i have the money, and by that time i should have a different daily so down time wont matter. From what i have been researching, if i get too impatient, i will just go ahead and get a t25 flange and make it work right now and block of the external waste gate until i can afford a similar turbo to what ur runnin and a 38mm wastegate. Thanks for all the help

[ericb382]

Yeah im running the ISIS manifold. 555cc injectors, HKS step 2 cams. Turbo fab top mount manifold and the 50 trim 63 ar turbo from enjuku.

Made 372whp at 17psi letting off at 6400rpm.

Holy $h!t that sounds like you're pushing those injectors! What fuel pressure are you running? Have you monitored your inj duty cycle?

[kentuckyslider]

First of all what are you using for tune?? If you are running 19psi thru a T28 now then I would get this.

http://cgi.ebay.com/ebaymotors...6f73b

Just as good if not better turbo then a 50 trim and spools about as quick as a GT2871r with the 9cm2 housing. Should make very close to 400whp at 19-20psi with some cams and a good tune. If I was you I'd get a quality 38mm external wg and a HY35 for less than $300. Fab a 3" DP and rock out for less than $500 more bucks if you can do most of it yourself??

[Sil80315]

Holy $h!t that sounds like you're pushing those injectors! What fuel pressure are you running? Have you monitored your inj duty cycle?

Not sure what duty cycle the injectors were at because I didnt have a safc hooed up but fuel pressure was at 45psi but i can imagin the injectors were probably around 90%.

I wouldnt go any bigger of a turbo with out upgrading to 740's or 72lb injectors

[fabrisuzu]

I really like the holeset turbos and have talked to the guys at gsr racing about the hx35 and that is a serious option for me to consider http://www.g-s-racing.com/products.html. I know that the gsr one is a twin scroll so when i went with the peak boost i kinda checked it off my list, but i guess its time to reconsider. I have a safc2 with wide band, but def want to get a dyno tune from AMS once i get a decent build going. Right now im in the planning stages, and am trying to weigh out doing stuff now or saving for stuff later. Either way, im sure most of this wont be on my car for a while because i just bought 2 new wheels and will need new tires once sping comes around so money is tight (college kid not working). If all goes well ill graduate this spring so hopefully have a real job and can put some real work into this project. Thanks again for all the help, still deciding, but i really appreciate all your help.

Hey kentuckyslider, didnt you use the hx35? How'd that work out for you if u did?

[kentuckyslider]

Hey kentuckyslider, didnt you use the hx35? How'd that work out for you if u did?

It worked out like this....



This was at 24ish psi. The only problem is the twin scroll 12cm2 housing on the HX35 is a little lazy on a single scroll mani. It would have been better with a BEP .70ar single scroll exhaust housing and your tubular mani. I could have made the same numbers as above with an HY35 just spooled 400-500rpm quicker and had more area under the curve. The HY35 and HX35 have the same compressor and cover just the HY35 has a smaller exhaust housing and spools quicker. If you aren't trying to make over 450whp then the HY35 is the way to go on an SR. Even if you do get the HX35 you need to invest in the BEP .70ar exhaust housing and be prepared to run over 30psi of boost to get the full potential out of the HX35!! This is my experience with the Holsets on the SR!!!

The 7 blade (60lb/min) HX35 comes on all manual transmission dodge cummins trucks from 98.5-2002 and the HY35 came on all trucks with the Auto transmission. The only reason for the smaller turbine housing was to allow the auto trucks to pass emissions with the turbo spooling while on the converter.
Modified by kentuckyslider at 9:38 PM 12/13/2009

[fabrisuzu]

Kentuckyslider,Lots of really good info man thanks a ton! I think now i will wait until i can afford the hy35 and go from there. Your dyno is exactly where i want my car for the time being so it is very nice to see that you and sil80315 are getting the numbers i want with similar builds. Thanks again for all the help guy! i really appreciate it and this is why nico rules! Ill update this with some pics when my manifold come in. Peace