hx40 or hx35 on pump gas? lag-adverse

[redaphid]

Hey guys. Long time lurker-in-the-shadows, first time poster. Doesn't seem to be a lot of info for these Holsets on pump gas though.

I'm wondering what to buy with my tax break (hx35 or hx40, bullseye housing). Here are my mods:

660cc injectors
6 bolt swap
wiseco pistons/eagle rods
dsmlink
greddy fmic & wastegate.
Act 2600 clutch
other random boltons/supports.
BigT28

I know I'l probably run out of injector duty with either of these turbos, but I'm wondering which one will give me the best performance on pump gas, as I'll never run race. I'm also a bit nitpicky about lag, so if anyone has info on the difference on spool-up for a 2.0l on these turbos that'd be great.

Pump dynos on either would also be a big plus!

Thanks guys. I've never seen a forum as helpful as you've been over the years. I've definitely gone from driver -> mechanic from a combination of amazing dsm reliability and this forum.

 

[kqodprez]

Redaphid, do a search on this site. There is like a 5 thread long discussion about these turbo's. I'm picking mine's up today due to the research that I've read upon. One of my friends has one on his VR4 and it's great! Your 660's will be maxed out so if you have plans/find some cheap injectors I'd pick them up (850's or higher). Hope you join the HX35 club!

 

[toofast82]

It really depends on what your goals are. I didnt see cams and smim listed so if youre planning on keeping those stock i would say go with the 7blade hx35. It is a 60lb/min compressor but is said the bolt on .55ar housing might not be able to max out its full potential, while it is plenty capable of maxing the 8blade hx35 52lb/min compressor. Reaches 20psi by 35oorpm in 3rd with 272s so your stock cams will spool a little quicker. This is a 500+whp capable turbo with good spool capability with room to grow in a t3 setup.

 

[50trimmed1g]

Hx40 Is what I'd go with based on reading through the holset threads. Full boost as quick as my 50 trim, 600 hp capable. What more could "I" want. I do like shear speed though.. If you like autocross or road racing an hx35 might be more suitable for you

 

[toofast82]

Hx40 Is what I'd go with based on reading through the holset threads. Full boost as quick as my 50 trim, 600 hp capable. What more could "I" want. I do like shear speed though.. If you like autocross or road racing an hx35 might be more suitable for you

Just because its capable of 600hp doesnt mean he will even come close especially with stock cams/im. The 7blade hx35 is 60lb or 600hp capable but will spool faster due to smaller turbine and most likely be more suited to his powerband as well as the compressor. These big numbers are made at 25psi+. Honestly he is probably better suited with a 16g-20g if he plans on running less than 22psi.

 

[redaphid]

I run 21 psi on the Big28, and I'm a little disappointed, to be honest. Although, I guess it's an internal gate so I lose quite a bit of boost up top.

My afrs are about 10.5 these days, which I guess is a little rich for good power. I need some time to do a good tune.

I thought about 16gs, but they are around the same 'class' as the big28, right? If I'm gonna spend some money, I want to see a big difference.

I did read a lot of the Holset threads. A lot of people say the hx35 spools at least as quick as a 16g (dsm-onster had some pretty good evidence with dsmlink, if I remember correctly).

What I'm really concerned with is power/money (have a dsm, should be obvious ) and their performance on pump gas, which hasn't really been covered anywhere that I can find.

I guess you guys are saying hx35 might be the better choice for me. How much quicker does it spool than the hx40? I don't mind buying bigger injectors or cams down the road, but it seems that aftermarket cams actually increase lag in most cases.

I'm looking for a more streetable car, but with the most power I can get out of it

 

[toofast82]

I run 21 psi on the Big28, and I'm a little disappointed, to be honest. Although, I guess it's an internal gate so I lose quite a bit of boost up top.

My afrs are about 10.5 these days, which I guess is a little rich for good power. I need some time to do a good tune.

I thought about 16gs, but they are around the same 'class' as the big28, right? If I'm gonna spend some money, I want to see a big difference.

I did read a lot of the Holset threads. A lot of people say the hx35 spools at least as quick as a 16g (dsm-onster had some pretty good evidence with dsmlink, if I remember correctly).

What I'm really concerned with is power/money (have a dsm, should be obvious ) and their performance on pump gas, which hasn't really been covered anywhere that I can find.

I'm looking for a more streetable car, but with the most power I can get out of it

The hx35 does not spool "at least as fast" as a 16g in "every gear". I have run the hx35 before as well. Tuning will make a big deal with spool with any turbo you choose. I would focus on getting some cams and smim so that you could max out a turbo that flows as much as hx35. You really havent mentioned any power/e.t. goals which makes it difficult. If your looking for 35owhp, you really dont need hx35. It is more ideal in the 450-525whp range imho

 

[jrohner]

Full boost 'as fast as a 16g' and 'by 3500 rpms' are quite different. My 16g has full boost at 2700-2800, and back when I had a SMIC it was 2500. My BC272 cams made no difference in spool.

 

[UGOT8UP]

When do you plan on buying? I'm fixing to put my HX35 8blade with the BEB housing as soon as I get my oil line's...I currently have a E316G on there now, so I could do a good comparison between the two of them.

 

[dsm-onster]

My hx35 turbo ('big' h1c with the bep bolton turbine housing) makes the same boost in the same gears at the same time as did my small 16g. I lost about 400rpms in spool to 20 psi when going from stock cams to fp2 cams with the 16g (7cm^2 td05h turbine). Every other person I've talked to directly or tuned their car has been the same: stock cams to 272s or fp2s loses 3-500rpms spool speed in third gear. Third gear is the common 'test' gear for spool speed. Different cams will alter the boost curve differently under different loading conditions (different gears, vehicle weights, turbines, compressor efficiencies).

My hx35 turbo sees full boost by 3500rpms with the bep housing as also confirmed by Maglin, another hx35 user, and *several* others you will note as you read through the threads. He!!, even TimG, who runs an hx35/40 with the stock 12cm^2 turbine housing without a divided runner manifold sees 20-22psi by 3900-4000rpms. His logs are posted in the holset threads (#3 I think). Here's the hx40 spooling to 20psi by 3900rpms with the bolton housing in 3rd gear. How can a much smaller hx35 turbine wheel NOT spool to full boost by 3500-3700rpms??!!??!!

Redaphid, how much horsepower do you want?

 

[redaphid]

Well, guys, I guess I'm going to have to give up on this project.

My built 6 bolt seized due to oil starvation. I checked the oil about a month ago, and it was fine. Doesn't seem to leak oil either. Ugh, I don't know what to do.

 

[19BLACKGST98]

Just build a motor. No reason to get rid of a 99 GSX. If you are going to get rid of it I would like to know what color it is and how many miles are on the chassie?

EDIT: Nevermind I just saw that you are in washington. Get your motor built and put some crower valve springs in your head. Then pick up one of your holsets and you will be golden