After realizing my turbo was too big or my 306 was too small I needed to make a change. Either build a larger engine or find a turbo more suited to my 306. My engine is a Dart based 306 with forged internals and TFS-R heads, Spetter Hyd roller Cam, Igloo Cooler. It made decent power on the Dyno. 550rwhp on 93 oct @ 15 psi, and 739rwhp on c-16 @ 25psi. The converter needs to be tightened up. Power comes in above 5k. I did some homework and decided to change the turbo since I am not going to compete in any class except possibly a true street event. I have a PTE74GTS on my stock block 95 lightning and that turbo works very well. I custom built the turbo system on the mustang to accept the S400-88 turbo. I was looking for a S400 style turbo to replace the larger S400-88. I picked up a S400-SX turbo from Dave@ Majestic. The wheels are similar in size to the PTE74GTS all in a T-6 Package. I will keep you posted to the performance differences after I bolt in the S400SX this weekend. If it is perfect I will be selling the S400-88. The S400-SX is on the left, the S400-88 is on the right.

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The 88mm wheel in the turbo on the right is awesome. The new one will definitely come on strong.

 

I agree. Who built it?

 

Majestic Waco built the S400-88.

 

So does your new S400SX have the 75m compressor and 83mm turbine? That should definitely come on a lot harder then the 88/96 S400 you had.

Justin

 

Yes the S400-SX does have the 75mm ETT comp and the 83mm turbine wheel. It coming on alot sooner is exactialy what I want to hear. Thank You.

 

I have a freind that may be interested in the bigger turbo if you get rid of it, pm me a price. Thanks

 

When you get em, I would definitely like to see dyno results. The turbine T4 or T6?

 

Drac0nic, Both turbos are the t-6 flange. 1.10A/R on the S400-SX and 1.32 A/R on the S400-88. With it snowing here today I was hoping to test the new turbo on the street but I dont think that will happen, so I might head to the dyno. I have a loose converter that the car blew threw with the S400-88, I dont know if the S400-SX would show any better dyno graphs. Where it spools is what I am looking to improve on. I should be able to test that on the trans brake, this weeked, if the weather is bad. I'll keep you posted.

 

Re-read the post, and the 88 is using the larger turbine wheel so it will be fine. I spoke to another gentleman earlier that said the 88 was coupled with the smaller turbine wheel, but apparently its not. If so that would be a turd....

 

The old turbo is a S400-88 with a 96mm turbine inducer and 88mm turbine exducer. The compressor wheel is a Garret 88mm wheel 88mm inducer and 118mm exducer. The compressor wheel flows 120lb/min. The new turbo is a S400-SX with the 75mm ETT Comp wheel and 83mm Turbine inducer and 74mm turbine Exducer. Hope this clears up any confusion.

 

Hi Gen1sve,

Any updates on the s400sx turbo? I am planning a s400sx T4 build on my 88 hatch with meth injection, intercooler, stock block 302, freshened with new rings, bearings, F cam, AFR 185's, Mega Squirt, 60lb injectors, bbk intake, built c4 with transbrake & reverse manual valve body, 3.73 gears, slicks, & lightened body.This will be a 1/8ith mile track only car with a few quarter runs thrown in. I will add subframe connecters and a 10 pt rolll cage too. My ultimate goals are high 5's in the 1/8th & high 9's in the the quarter.

So many people on here do MPT70 builds on a stock block 302's, with high perf cam, heads intake etc. Dave at majestic talked me into the s400sx saying its more efficient so I should run faster at similar boost. I will max boost at 20 - 22 lbs. And if I ever upgrade my block I can upgrade the turbo to a T6 88MM and be in the mid 8's in the quarter as an all out race car. I want to learrn to tune and race etc on my stock block 302. If I blow the short block, big deal, I just go to the junk yard and grab another 5.0 302 short block and freshen it. I will eventualy go to a Boss 302 block with a 367 cid stroker kit for racing.

Just curious how yours ran with a s400sx turbo on a 306 cid motor. What rpm it boosted etc. It has to me a much stronger turbo than a MPT70. I want to keep my power band or rev range from about 3000 RPM to 6300 if possible, to meet my performance goals. Turning up the boost and keeping the revs down equals a longer lived short block! lol

Hpbob

 

It did not help as much as I thought it would. If you keep the compression reasonable 8.5:1+ it will be a great turbo much better than the MP70. I put the S488 back as the sx changed the VE and I do not have a wideband as of yet and can not monitor any changes to the tune. I am making changes to the tune for spool and I am getting close. The car did run a 10.49@137 @ 20#. Keep in mind I the motor is barley 8:1. I do have the sx and if I get a wideband and do not get the 88 to work I can swap it out and retune, or change pistons. If not the sx will go on my lightning.

 

totally different motor but here are my results with a Miketurboinc s488 t-6 1.32 a/r
408 ls1
12 psi
[email protected]
1.57 60'
4000# raceweight
2400 stall and 3.08 rear
2psi launch